Want to skip right to the survey? Click here! (Must be at least 18 years old and have graduated or be close to graduation from a US academic institution in chemistry or a closely related field.)

Every time I go back to Wisconsin to visit my family, I get asked the same questions: “So, how is your research going?” “Why do your experiments never seem to work?” “When are you going to graduate?”

“Wait, explain to me what you even do again?”

Have I explained my research to them hundreds of times at this point? Perhaps. But they’re not chemists; my parents are accountants (and not the fun kind), my brothers are computer geeks, and I am the sole scientist. So every time they ask, I try and explain my research to them in a way that makes sense: I say that I am making glow-in-the-dark particles called carbon dots that will change colors when they touch bad bacteria like Salmonella or Listeria.

They don’t need to know that my materials are technically not glow-in-the-dark because they’re fluorescent, not phosphorescent, and the timescale of fluorescence is much shorter than it is for phosphorescence. They also don’t need to know that I am being completely delusional when I say it will change colors when interacting with bacteria; at best, it will glow less bright, and the suppression of the fluorescence is what will help me to detect and quantify the amount of bacteria present. They also don’t need to know that it’s unlikely I’m going to be able to detect both Salmonella and Listeria because one is Gram positive and one is Gram negative and their surface chemistries are very different, necessitating very different glow-y nanoparticles to detect them. They don’t need these details to get excited about what I am doing, and that excitement is what is important to convey. As long as their eyes are not glazing over with boredom and confusion, I am doing my job of effectively communicating my science. And sometimes they might even ask follow-up questions about some of those details!

Frequently, people view scientists as ineffective communicators who are only concerned with being viewed as the smartest person in the room. In fact, a 2024 Pew Research study found that more people view scientists as having a superiority complex than as being good communicators (woof).

Not to say those haughty scientists don’t exist, but the world of science communication extends so much further than confusing and frankly eyeroll-worthy presentations that only a small sliver of the population could possibly understand. It’s also present in BBC nature documentaries, in your local aquariums, in butterfly museums, and in YouTube video essays about the history of life on earth (check out Lindsay Nikole, by the way; her videos are my latest hyperfixation because she’s a very effective science communicator!). It’s present in the blog post I wrote about how you can use crochet to model nanotechnology. And yes, it is present in conversations with my parents about my graduate studies.

Now more than ever, it is important for scientists to put value on engaging with non-scientists and talking about science effectively. Despite science communication and outreach work helping to further research institutions’ goals for community engagement, some researchers still see it as a distraction from academic progress. Support for students to learn about and engage in science communication with the public can vary a lot across different graduate programs – and even among research groups within each program. But we don’t really know how those differences can shape a graduate journey, and lately I’ve been really invested in this issue. For example, do people who care about science communication learn how to do it on their own regardless of programmatic support? Does having support to explore science communication and outreach during graduate school influence how scientists approach public communication after they get their PhD?

To help explore these questions, I have created a study looking at how participation in science communication and outreach during graduate school affects post-graduate outlooks. One of the hypotheses being explored is about how employers versus academic institutions value science communication skills. Results from this survey could be used to support decisions about investment in developing these skills throughout graduate school.

If you are interested in participating in this study, you can use this link or scan the QR code below. Participants must be at least 18 years old and have graduated (or intend to graduate within the next year) from a US academic institution in chemistry or a closely related field. All survey submissions are anonymous, and there are no foreseen risks associated with this study.

Thank you for considering participating in this study!

REFERENCES

1. Juhasz-Dora, T.; Lindberg, S.-K.; Karlsen, A.; Ortega, S. Biofluorescent Response in Lumpfish Cyclopterus Lumpus to a Therapeutic Stressor as Assessed by Hyperspectral Imaging. Sci Rep 2024, 14 (1), 2982. DOI: 10.1038/s41598-024-53562-7
2. Tyson, A. & Kennedy, B. Report: Public Trust in Scientists and Views on Their Role in Policymaking. Pew Research Center 2024. Retrieved from https://www.pewresearch.org/science/2024/11/14/public-trust-in-scientists-and-views-on-their-role-in-policymaking/

I feel a mix of celebration, sadness, and defiance as I sit down to write about Pride Month here on the Sustainable Nano blog. Given the current administration’s attacks on people with various marginalized identities, including LGBTQIA+ folks,^1,2 it feels more important than ever to celebrate the identities, accomplishments, and histories of resistance among the queer community, especially in science. Queer folks have always been part of STEM, whether “mainstream” institutions accepted their existence or not.³ As Elizabeth Stivison points out in “LGBTQ+ scientists in history,” many scientists have felt the need to hide their identities (when that was possible) in order to succeed in STEM.⁴ But I am heartened by the joy, defiance, and persistence in the community I see all around me in scientists like Andre Isaacs, Chanda Prescod-Weinstein, and Riley Black. (People with marginalized identities shouldn’t have to work so hard to just exist in scientific communities and I hope that by taking up the topic here as a straight-cis-white woman, I can take a tiny burden from my colleagues who usually don’t have a choice about opting in to this work because of who they are.)

As the Center for Sustainable Nanotechnology is coming to a close in just a couple of months – and this blog along with it – I can think of no better topic than Pride Month as the focus for one of our final posts. (After 13 years of funding, the CSN was not eligible for another grant renewal, even before the proposed gutting of the National Science Foundation.⁵) Our tag line of “Nanotechnology, Sustainability, and Life in Science” has always been meant to capture the range of human experience that is part of the endeavor of science. The CSN is not a building or a collection of papers; it is a community of scientists, valuing each other as whole people as we work together on big scientific questions.

Others have already written more than I ever could – and more eloquently – about the experience of being queer in STEM. So perhaps the most helpful thing I can do is to point readers toward a few resources to explore more deeply and find community, or to understand better how to provide support for queer colleagues in STEM.

First, be sure you check out a few other relevant blog posts from members of the CSN:

• Applying to Graduate School: Advice for LGBTQ+ students from the community
• Artivism in Chemistry
• #InfertilityUncovered

Other online reads & references

• 500 Queer Scientists visibility campaign
  • 2018 interview with co-founder Lauren Esposito
• oSTEM.org (Their annual conference is Oct 16-18, 2025 in Baltimore, MD.)
• Support for LGBTQ+ chemists must include addressing their basic needs by R. Lee Penn and Argo Farlin
• The TikTok Chemist – profile of Andre Isaacs by Alice Motion
• NASA Pride Flag: The story of the pride flag made from NASA imagery: Bluesky’s most-liked image by David Shiffman (Note that the original link to where this image appeared on the NASA website is now broken – just one example of the erasure being perpetrated by the current administration.)
• The James Webb Space Telescope Needs to Be Renamed by Chanda Prescod-Weinstein, Sarah Tuttle, Lucianne Walkowicz & Brian Nord in Scientific American
• ‘A towering legacy of goodness’: Ben Barres’s fight for diversity in science By Sarah Kaplan in Standford University’s Neuroscience News

Books

• The Disordered Cosmos: A Journey Into Dark Matter, Spacetime, and Dreams Deferred by Dr. Chanda Prescod-Weinstein, Associate Professor of Physics and Core Faculty Member in Women’s and Gender Studies at the University of New Hampshire.
• Autobiography of a Transgender Scientist by Dr. Ben Barres, Chair of the Neurobiology Department at Stanford University School of Medicine (see list above for a lovely obituary of Prof. Barres)
• Virology: Essays for the Living, the Dead, and the Small Things in Between by Joseph Omundson, Professor of microbiology at New York University
• How Far the Light Reaches: A Life in Ten Sea Creatures by Sabrina Imbler, Staff Writer at Defector
• A Little Queer Natural Historyby Josh L. Davis, Science Writer for the Natural History Museum in London

I know these lists only scratch the surface. Comment below or on BlueSky with your favorite suggestions to add!

REFERENCES

1. Ramaswamy, Swapna Venugopal. “LGBTQ+ advocates see Trump’s actions on Pride Month as ‘bullying’.” USA TODAY, 5 June 2025, https://www.usatoday.com/story/news/politics/2025/06/05/trump-administration-pride-month-lgbtq-policies/84027617007/.
2. Parshall, Allison. “How Supreme Court Trans Health Care Ruling Will Affect Kids. Scientific American, 18 June 2025, https://www.scientificamerican.com/article/supreme-court-skrmetti-decision-permits-ban-on-gender-affirming-care-for/.
3. Langin, Katie. “NSF still won’t track sexual orientation among scientific workforce, prompting frustration.” Science, 13 January 2023, https://www.science.org/content/article/nsf-still-won-t-track-sexual-orientation-among-scientific-workforce-prompting.
4. Stivison, Elizabeth. “LGBTQ+ scientists in history.” American Society for Biochemistry and Molecular Biology Today, 18 June 2021, https://www.asbmb.org/asbmb-today/people/061821/lgbtq-scientists-through-history.
5. Mervis, Jeffrey. “Exclusive: NSF faces radical shake-up as officials abolish its 37 divisions.” Science, 8 May 2025, https://www.science.org/content/article/exclusive-nsf-faces-radical-shake-officials-abolish-its-37-divisions.
6. Oloyede, Kemi. Queer, PoC, Creative, STEM. Analytical Chemistry, 2021, 93(21), 7541–7542. doi: 10.1021/acs.analchem.1c01826.

Plastic pollution has become one of the biggest global environmental challenges in recent years. Around 10% of plastics produced each year end up as waste in water bodies.¹ Approximately 30 million tons of plastics are released into the environment each year with impacts to soil, freshwater, groundwater, and surface waters that are of global concern.² The global demand for plastics is mainly driven by thermoplastics like polypropylene (PP, found in food storage containers), polyethylene (PE, found in plastic bags and food packaging including bottles, containers, and wraps), and polyvinyl chloride (PVC, found in water pipes). Other commonly used plastics include polystyrene (PS, found in foam packaging), expandable PS, and polyethylene terephthalate (PET, found in plastic water bottles and soda bottles).

Plastics are not just used for consumer products but also for making synthetic fibers, foams, coatings, adhesives, and sealants which are essential in various industries.⁴ Over time, plastics degrade into smaller fragments: you may have heard of microplastics, which range from 0.1 μm to 1 mm smaller than a width of a pencil tip), but they can also break down farther into nanoplastics, which are smaller than 100 nm in size( one thousandth the thickness of a sheet of paper)^2,4.  This breakdown occurs through biological, chemical, and physical processes. ² Biological processes happen when living organisms digest or metabolize plastics. Chemical processes happen when certain chemicals interact with the plastic and break it apart at a molecular level. Physical processes are caused by things like ultraviolet light, weather, and mechanical forces like the plastic simply scraping across dirt or rocks. As plastics degrade, they can break down into smaller and smaller pieces or particles.

What do these different kinds of degraded plastics mean for humans? Tiny particles like micro- and nano-plastics can easily get into our bodies in various ways. Many research studies have found plastics present in human bodies, including in the blood and brain, heart and kidneys, liver and lungs, human milk and placenta, and testicles and semen.⁵ For example, one study found >700 nm plastic particles in human blood, and another reported 2-12 μm microplastics in human breast milk.⁵  A single plastic teabag could generate approximately 11.6 billion microplastics and 3.1 billion nanoplastics in hot water.¹ Infant feeding bottles made of polypropylene have been found to release up to 16 million nano-/microplastic particles per liter in to  infant formula.⁶ Therefore, infants are at risk of plastic exposure from consuming formula prepared in polypropylene bottles. Nanoplastics can also be released into food and drink from food packages such as paper cups, instant noodle containers, and take-out boxes. When consumed, these nanoplastics can infiltrate bodily tissues through cellular internalization and may result in toxicological consequences.⁵

Simply put, nanoplastics can enter the human body through food, tap water, and plastic beverage bottles contaminated with microplastics and nanoplastics. Scientists have found seafood (mollusks—including mussels, oysters, and clams) and sea salt to be highly contaminated with nanoplastics. Furthermore, agricultural products such as fruits and vegetables can absorb nanoplastics through plant roots when grown in contaminated soil, allowing these particles to enter the human body upon consumption.⁵ And studies suggests the presence of plastics in the human body may cause health complications such as cognitive impairment, or neurodegenerative diseases like Alzheimer’s disease (AD) and Parkinson’s disease.^1,7,8 For example, in one study, human neuronal cells were found to internalize polyethylene nanoplastics (33 nm), and developed abnormalities following semi-acute (48 h, 22.5–1440 mg/L) and chronic (18 days, 22.5–360 mg/L) exposure. The internalization of nanoplastics was associated with altered gene expression and oxidative stress. Also at high concentrations (≥180 mg/L), more cells died.⁷

The Blood-Brain Barrier

The blood-brain barrier (BBB) is a protective barrier that separates the brain from the blood. It is semi-permeable, meaning it carefully controls what enters and leaves the brain. This barrier allows essential nutrients and oxygen to pass through while blocking harmful substances, helping to maintain a stable environment for brain function. Scientists have found that nanoplastics can pass through the BBB by attaching to the membrane and getting endocytosed.⁵ Endocytosis is like a cell “eating” or “drinking.” The cell wraps around a molecule, pulls it inside, and forms a small bubble-like structure to transport it. This helps the cell take in nutrients, remove waste, or communicate with its environment.

One study on mice models has shown that exposure to nanoplastics increases the permeability of the BBB. This means that substances that would normally be blocked by the BBB could pass into the brain, triggering inflammatory responses. Furthermore, the studies that investigated the neurotoxicity of one type of nanoplastics showed that nanoplastics crossing the BBB activates microglia (a type of clean-up cell in the brain and central nervous system).¹¹ Microglia are a key part of the immune defense system in the brain which respond to pathological events. Additionally, findings suggest that the synergistic interactions of nanoplastics with other biomolecules can trigger neurotoxicity.¹ Overall, nanoplastics exposure can lead to increased production of reactive oxygen species (ROS)⁸ which may cause oxidative stress, inflammation, and DNA damage⁵. These in turn can cause long-term effects such as increasing the incidence of neurodegenerative diseases like Alzheimer’s disease.¹

Detection methods

Scientists have been working for a long time to learn about the health consequences of nanoplastics in humans and the environment. One of the most fundamental challenges of nanoplastics research is simply being able to detect the nanoplastics in our blood and other tissues. Because these particles are less than 100 nm, we need specialized instruments to see them. Research shows that nanoplastics have a greater potential than microplastics to cause harm because they are so small that they can actually get inside of individual cells.⁵ And as we’ve discussed in previous blog posts, the high ratio of surface area to volume makes nanoparticles (including nanoplastics) more reactive than larger particles.¹² Accurately quantifying and characterizing the nanoplastics infiltrating our bodies requires multiple complementary detection techniques. For example, researchers use a technique called pyrolysis gas chromatography/mass spectrometry (Py-GC/MS) to identify and measure the levels of micro- and nanoplastics in tissue samples.¹³ This method involves digesting organic tissue with potassium hydroxide, separating the plastic particles using an ultracentrifuge, heating the collected plastic, and using a mass spectrometer to analyze the gas emissions to identify and quantify different polymers.⁵ However, the Py-GC/MS method has limitations. It can be difficult to detect certain plastics like polyethylene and polyvinyl chloride. Also, the digestion process can create residues that might interfere with the analysis. Py-GC/MS also does not provide information about the nanoparticle shape and size. Other techniques like Raman spectroscopy and machine learning approaches also have been used in detection of nanoplastics.¹¹

Techniques like fluorescence microscopy and electron microscopy are helpful but pose a challenge in spotting the tiny plastic particles in tissue samples. The nanoplastics are more difficult than other materials to detect using electron microscopy because they actually don’t have a ton of electrons! (They’re not “electron dense” like gold and other metallic materials that make great electron microscope subjects.)

Key takeaways

While the full scope of the impact of nanoplastics on human health and the environment is still being uncovered, the research is clear: nanoplastics pose a significant threat that cannot be ignored. The projected doubling of global plastic production by 2050⁵ underscores the urgent need for action. These tiny particles are not just a distant concern; they are already infiltrating our bodies, with studies finding them in human blood, breast milk, and even the brain. The potential health consequences, including neurodegenerative diseases and other serious conditions, are alarming!

Using environmentally friendly alternatives to plastics can significantly benefit human health and environmental sustainability. The responsibility is not only with the global scientific community but also with the corporate sector. Global corporate responsibility in reducing plastic usage can take many forms. Just a few examples:

• Sustainable packaging: Invest in biodegradable, recyclable, or reusable packaging to minimize plastic waste.
• Supply Chain Optimization: Reduce plastic use in logistics and transportation by using eco-friendly alternatives.
• Product Innovation: Develop plastic-free or minimal-plastic products to reduce reliance on traditional plastics.
• Recycling Programs: Implement take-back programs for plastic products and support global recycling initiatives.
• Corporate Partnerships: Collaborate with governments and NGOs to drive large-scale plastic reduction initiatives.
• Consumer Education: Raise awareness and encourage responsible consumption through campaigns and incentives.

I hope this post has contributed to the consumer education piece of the puzzle. However, there is also reason for optimism. The growing awareness of the problem is driving innovation and change. Companies are starting to invest in sustainable packaging, optimize their supply chains, and develop plastic-free alternatives.¹⁴ Furthermore, scientific research is continually advancing our understanding of health and environmental impact of nanoplastics, and also designing sustainable polymers that can replace conventional plastics.^16,17 The responsibility for addressing this challenge lies not only with the scientific community but also with corporations and consumers alike. By supporting companies committed to reducing plastic waste, advocating for stronger regulations, and making conscious consumer choices, we can collectively mitigate the risk posed by nanoplastics. This is not just about protecting our own health but also safeguarding the health of future generations and the planet. The time to act is now, to ensure a healthier, more sustainable world for all.

References

1. Gou, X.; Fu, Y.; Li, J.; Xiang, J.; Yang, M.; Zhang, Y. Impact of Nanoplastics on Alzheimer’s Disease: Enhanced Amyloid-β Peptide Aggregation and Augmented Neurotoxicity. Journal of Hazardous Materials 2024, 465, 133518. DOI: 10.1016/j.jhazmat.2024.133518.
2. Teng, M.; Zhao, X.; Wang, C.; Wang, C.; White, J. C.; Zhao, W.; Zhou, L.; Duan, M.; Wu, F. Polystyrene Nanoplastics Toxicity to Zebrafish: Dysregulation of the Brain–Intestine–Microbiota Axis. ACS Nano 2022, 16 (5), 8190–8204. DOI: 10.1021/acsnano.2c01872.
3. Hahladakis, J. N.; Velis, C. A.; Weber, R.; Iacovidou, E.; Purnell, P. An Overview of Chemical Additives Present in Plastics: Migration, Release, Fate and Environmental Impact during Their Use, Disposal and Recycling. Journal of Hazardous Materials 2018, 344, 179–199. 10.1016/j.jhazmat.2017.10.014.
4. Rani-Borges, B.; Ando, R. A. How Small a Nanoplastic Can Be? A Discussion on the Size of This Ubiquitous Pollutant. Cambridge Prisms: Plastics 2024, 2, e23. 10.1017/plc.2024.25.
5. Should we be worried about the microplastics in our bodies? https://cen.acs.org/environment/pollution/Should-worried-microplastics-bodies/102/i37 (accessed 2025-02-01).
6. Li, D.; Shi, Y.; Yang, L.; Xiao, L.; Kehoe, D. K.; Gun’ko, Y. K.; Boland, J. J.; Wang, J. J. Microplastic Release from the Degradation of Polypropylene Feeding Bottles during Infant Formula Preparation. Nat Food 2020, 1 (11), 746–754. DOI: 10.1038/s43016-020-00171-y.
7. Prüst, M.; Meijer, J.; Westerink, R. H. S. The Plastic Brain: Neurotoxicity of Micro- and Nanoplastics. Particle and Fibre Toxicology 2020, 17 (1), 24. DOI: 10.1186/s12989-020-00358-y.
8. Liu, Z.; Sokratian, A.; Duda, A. M.; Xu, E.; Stanhope, C.; Fu, A.; Strader, S.; Li, H.; Yuan, Y.; Bobay, B. G.; Sipe, J.; Bai, K.; Lundgaard, I.; Liu, N.; Hernandez, B.; Bowes Rickman, C.; Miller, S. E.; West, A. B. Anionic Nanoplastic Contaminants Promote Parkinson’s Disease–Associated α-Synuclein Aggregation. Sci Adv 9 (46), eadi8716. DOI: 10.1126/sciadv.adi8716.
9. Paul, M. et al. Micro- and nanoplastics – current state of knowledge with the focus on oral uptake and toxicity. Nanoscale Adv, 2020, 2, 4350-4367. DOI: 10.1039/D0NA00539H
10. Alahmari, A. Blood-Brain Barrier Overview: Structural and Functional Correlation. Neural Plasticity, 2021 (1), 6564585. DOI: 10.1155/2021/6564585.
11. Shan, S.; Zhang, Y.; Zhao, H.; Zeng, T.; Zhao, X. Polystyrene Nanoplastics Penetrate across the Blood-Brain Barrier and Induce Activation of Microglia in the Brain of Mice. Chemosphere 2022, 298, 134261. DOI: 10.1016/j.chemosphere.2022.134261.
12. Hudson-Smith, N. Valentine’s Day Science: What do M&Ms have to do with nanotechnology? Sustainable Nano: a blog by the NSF Center for Sustainable Nanotechnology. 2019. https://blog.susnano.wisc.edu/2019/02/14/valentines-day-nanotechnology/
13. Li, P.; Lai, Y.; Zheng, R.; Li, Q.; Sheng, X.; Yu, S.; Hao, Z.; Cai, Y.; Liu, J. Extraction of Common Small Microplastics and Nanoplastics Embedded in Environmental Solid Matrices by Tetramethylammonium Hydroxide Digestion and Dichloromethane Dissolution for Py-GC-MS Determination. Environ. Sci. Technol. 2023, 57 (32), 12010–12018. DOI: 10.1021/acs.est.3c03255.
14. Nihart, A.J., Garcia, M.A., El Hayek, E. et al. Bioaccumulation of microplastics in decedent human brains. Nature Medicine (2025). DOI: 10.1038/s41591-024-03453-1
15. Mars is reimagining packaging with innovations | Mars, Incorporated. https://www.mars.com/news-and-stories/articles/packaging-innovations-pilot-programs (accessed 2025-04-09).
16. Chaudhary, M. L.; Patel, R.; Gupta, R. K. Polymers with Chemical Recyclability: An Approach to Sustainability. In Depolymerization: Concept, Progress, and Challenges Volume 2: Advances and Breakthroughs; ACS Symposium Series; American Chemical Society, 2025; Vol. 1500, pp 1–16. DOI: 10.1021/bk-2025-1500.ch001.
17. Research Areas and Resources | Center for Sustainable Polymers. https://csp.umn.edu/research (accessed 2025-04-09).

Our planet’s climate is warming faster than ever before and exceeds known paleoclimate rates of climate change.¹ This rapid shift disrupts the delicate balance that allows plants and animals to thrive. As many as a million species are directly facing the risk of extinction caused by climate-driven environmental changes, with several other species being directly or indirectly affected. But there’s a twist: some organisms might be able to evolve and adapt to survive.² In this blog post, we’ll explore the fascinating world of climate change adaptation on the genomic level, changing organisms’ biology to survive a rapidly warming planet. However, it is important to recognize that while animals may adapt to a changing climate to some extent, their survival is not guaranteed. Therefore, it is crucial that we take responsibility for reducing our contributions to climate change to help safeguard their – and our – future.

Evolutionary Adaptation to Climate Change

Climate change is altering the planet very quickly, which provides an opportunity for scientists to study how it impacts a variety of species. This includes changes in evolutionary selection patterns, allowing species to adapt to climate change.³ While some species can move or adjust their behavior, a vital question emerges: can they evolve genetically in time to survive the altered climate? One area of research focuses on the potential of genetic adaptation as a buffer against climate change’s harshest effects. By inheriting traits that enhance survival in a new environment, populations can potentially avoid going extinct or having to drastically shift where they live. However, the picture is complex. A number of factors influence a species’ ability to adapt genetically, including existing variation, selection pressures, and other ecological processes. By understanding these complexities, we can better predict the fate of species in a changing world.^4,5

An important aspect of understanding genetic adaptation is to determine what traits are directly or indirectly influenced by climate change. Traits directly influenced may include how big the organism can grow, when it reproduces, and how it responds to changing.³ More indirect effects can include things like predator-prey interactions and parasitism³ or acidity and soil type causing a range shift.⁵

One of the most obvious consequences of climate change that affects humans is increasing temperatures. Studies have found that organisms can increase their thermal tolerance. For example, Daphnia magna (a little crustacean) showed increased heat tolerance in an experiment where temperatures were raised over two years. Similarly, Acropora hyacinthus (a species of coral) was able to adapt to increased temperatures and showed reduced levels of bleaching upon heat stress. The molecular mechanisms for this likely include biochemical adaptation of the organisms’ heat shock proteins – proteins that maintain cellular homeostasis and protect from stress – and decreased body size, which gives them a higher surface-to-volume ratio to allow for more efficient cooling.⁵

The ability of a species to adapt to climate change depends on factors such as genetic variation within populations, differences in genetic diversity across regions, and population size. High genetic variation provides more opportunities for beneficial traits to emerge, helping populations survive environmental changes. However, species with low genetic diversity, like certain Drosophila (fruit fly) species in rainforests, face evolutionary inertia. Evolutionary inertia means they struggle to adapt and are more vulnerable to extinction because they do not have many genetic variations to provide the “raw material” for natural selection to act upon. Populations with higher genetic diversity have higher chances of already possessing traits that could help the species survive in a changing environment. Individuals with those traits are more likely to survive and pass on the beneficial gene variations. Without enough variation, populations have fewer chances to evolve in response to climate change. Smaller organisms that have large populations are more likely to show genetic changes in response to climate change. This is because having more individuals and shorter lifespans allows for more genetic differences to appear over time, either by chance (genetic drift) or through new mutations.

However, organisms don’t always need genetic variation to get different results. (Think about how human identical twins always have some small differences even though their genes are the same.) When a single genotype (set of genes) produces more than one outcome (phenotype) in different environments, it is called phenotypic plasticity. Phenotypic plasticity is also an important aspect of species’ responses to climate change. To complicate the matter, phenotypic plasticity itself can also evolve in the context of adaptation to climate change. For example, climate change can alter temperature, pH, and CO₂ concentrations in the environments where organisms live, but those environments are often already inconsistent even without climate change added in. Thus, the evolution of plasticity may play an essential role to maximize organisms’ fitness in heterogenous environments, since the plasticity itself involves different versions of a given gene.⁶ For example, a study on Parus major (great tit birds) showed heritable variation in how individuals adjust their breeding times. This means that individuals inherited the ability to move their breeding time to whenever their caterpillar prey was abundantly available.⁵

Genetic adaptation is only one example of how animals can adapt to climate change. In my next blog post, I’ll approach this problem from a different angle: how animals adapt their migration patterns when the climate changes.

References

1. IPCC, 2021: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., et al. (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY. doi:10.1017/9781009157896
2. Fabbri, E., & Dinelli, E. (2014). Physiological Responses of Marine Animals Towards Adaptation to Climate Changes. In S. Goffredo & Z. Dubinsky (Eds.), The Mediterranean Sea (pp. 401–417). Springer Netherlands. doi: 10.1007/978-94-007-6704-1_23
3. Franks, S. J., & Hoffmann, A. A. (2012). Genetics of Climate Change Adaptation. Annual Review of Genetics, 46(1), 185–208. doi: 10.1146/annurev-genet-110711-155511
4. Edelsparre, A. H., Fitzpatrick, M. J., Saastamoinen, M., & Teplitsky, C. (2024). Evolutionary adaptation to climate change. Evolution Letters, 8(1), 1–7. doi: 10.1093/evlett/qrad070
5. Meester, L. D., Stoks, R., & Brans, K. I. (2018). Genetic adaptation as a biological buffer against climate change: Potential and limitations. Integrative Zoology, 13(4), 372–391. doi: 10.1111/1749-4877.12298
6. Kelly, M. (2019). Adaptation to climate change through genetic accommodation and assimilation of plastic phenotypes. Philosophical Transactions of the Royal Society B: Biological Sciences, 374(1768), 20180176. doi: 10.1098/rstb.2018.0176

¿Qué tienen que ver las nanopartículas de plata con los copos de nieve y el crochet? Por lo general, ¡no mucho! Pero recientemente, los científicos han creado métodos para hacer formas parecidas a copos de nieve a partir de nanopartículas de plata,¹ y sus métodos me recordaron no sólo a los copos de nieve sino también a cómo hago algunos de mis propios proyectos de tejer.

Entonces, ¿qué tienen en común estas diferentes formas? Los copos de nieve, como muchas otras estructuras del mundo natural, están compuestos de patrones llamados fractales. Los fractales son formas complejas que tienen unidades que se repiten a sí mismas, lo que significa que no importa cuán alejado o cercano estés, la forma parecerá consistente.

Tomemos, por ejemplo, un árbol desnudo. Al alejarlo, puedes ver un laberinto de diferentes ramas que salen de un tronco principal para formar todo el árbol. Si te acercas a una rama, comenzará a parecerse a un tronco del que salen ramas más pequeñas. Y si nos acercamos más, las ramas más pequeñas tienen aún más ramitas saliendo de ellas. Cada vez que hace zoom, la imagen consta de una unidad de repetición similar. Aunque eventualmente la rama de un árbol terminará en un capullo de hoja o una flor, en un fractal matemático puedes seguir acercándote infinitamente.

¡Los patrones fractales también entran en juego con los copos de nieve! En los copos de nieve, los cristales de hielo se forman como capas de moléculas de agua que se adhieren a las superficies congeladas del copo, y las esquinas se acumulan más rápido que los bordes formando un hermoso patrón de seis lados (consulte “La ciencia de la nieve” para conocer más detalles). Esto también crea un fractal natural, con los brazos teniendo regiones de ramificación adicionales que crean una sensación de autosemejanza independientemente de qué tan cerca estés del copo de nieve.

Pero, ¿qué pasa con el crochet? Como una entusiasta artista de fibras, también me alegra saber que los fractales sirven para crear patrones fáciles de tejer. Esto me ayudó a visualizar realmente cómo funciona el acercamiento y alejamiento de fractales simplemente relacionándolo con un proyecto parcialmente terminado. Tome este tapete que creé para comprender un poco mejor los fractales:

En las primeras etapas de la creación del diseño, forma un patrón en espiral distintivo.

A medida que lo construí más, se mantuvo de la misma forma general. No importaba qué tan avanzado estuviera el patrón, todavía se veía muy similar, solo que en un tamaño diferente.

Ésta es una de las características clave de un patrón fractal: es autosemejante a diferentes aumentos.

Un patrón fractal de ganchillo. Independientemente de qué tan ampliado o qué tan “hecho” esté el patrón, la forma general de la espiral sigue siendo muy similar. Los diferentes colores no son intencionales porque me quedé sin hilo. Observe el mismo ganchillo rosa en cada foto para tener una idea del tamaño creciente. (Fotos cortesía de Abby Stitgen, patrón cortesía de Zouzou Crochet³.)

En el mundo natural, así como en el crochet, existen límites en cuanto a qué tan pequeño o grande es el objeto antes de que deje de repetirse. Tomemos, por ejemplo, un copo de nieve tejido a crochet. En el patrón que hice, hay doce brazos que se extienden desde el centro alternando brazos largos y cortos, y en cada uno de esos brazos hay más perillas ramificadas (llamadas “picots” en términos de crochet). Sin embargo, es prácticamente imposible agregar más ramas al diseño (al menos, usando el mismo hilo) debido a los límites de lo pequeño que es un solo punto.

Esto es cierto para todos los fractales naturales: las ramas de los árboles eventualmente terminan, los copos de nieve no pueden seguir acumulando hielo más allá de un diámetro pequeño y una rama de crochet no puede ser más pequeña que una sola puntada. Pero en teoría, los fractales pueden repetirse un número infinito de veces. Tomemos, por ejemplo, una forma geométrica llamada copo de nieve de Koch:

En este diseño, cada iteración agrega un nuevo triángulo equilátero en el lado externo de un triángulo anterior. A medida que se va construyendo, la estructura adquiere la forma de un copo de nieve. Acercar cualquier lado externo, sin importar cuánto lo haga, daría la misma imagen de un triángulo con triángulos cada vez más pequeños adjuntos, repitiéndose hasta llegar a un triángulo infinitamente pequeño.

Ahora, volvamos a la nanotecnología. Recientemente, se ha investigado mucho sobre formas de aplicar diseños fractales a diferentes tecnologías. Después de todo, la previsibilidad de la estructura y la gran superficie pueden crear propiedades muy deseables que ya han sido explotadas en organismos naturales como árboles y plantas. Hemos hablado mucho en este blog sobre cómo el aumento de la superficie es un aspecto muy importante de la nanotecnología, y puedes ver que la superficie de la derecha es mucho mayor que la de la izquierda:

En un ejemplo del uso de fractales en nanociencia, los científicos han podido diseñar un fractal parecido a un copo de nieve hecho de nanopartículas de plata. Utilizaron péptidos para unir las nanopartículas de plata, haciendo que se agregaran en estructuras fractales hiper ramificadas.

Estudios preliminares han descubierto que estos fractales de nanopartículas de plata pueden usarse como sensor colorimétrico para diferenciar virus. Brevemente, lo que esto significa es que cuando se añaden proteínas virales a los péptidos puente y a las nanopartículas de plata, las proteínas virales pueden interferir con la construcción de los fractales de plata. Todo esto se puede visualizar a simple vista, donde las soluciones fractales son de un azul intenso y las soluciones con interferencia de virus son más rojas y amarillas. Aún más impresionante, los investigadores que realizaron el estudio pudieron diferenciar (¡con 100% de precisión!) entre muestras enriquecidas con coronavirus y muestras enriquecidas con influenza completamente por esta diferencia de color de interferencia fractal.

A medida que los científicos continúan descubriendo nuevas formas de crear fractales a nanoescala, podemos seguir aprovechando sus propiedades únicas. Otros beneficios de sus altas áreas superficiales pueden incluir la mejora de la actividad catalítica, y las propiedades ópticas mejoradas pueden explotarse en nuevos sensores. Los fractales demuestran que las formas naturales comunes pueden ser bastante geniales y tener propiedades científicas asombrosas.

Referencias

1. Retout, Yash Mantri, Zhicheng Jin, Jiajing Zhou, Grégoire Noël, Brian Donovan, Wonjun Yim, and Jesse V. Jokerst. ACS Nano 2022 16 (4), 6165-6175 DOI: 10.1021/acsnano.1c11643
2. Libbrecht, K. The physics of snow crystals.Reports on Progress in Physics, 2005, 68 (4), 855-895. doi: 10.1088/0034-4885/68/4/R03
3. Doily crochet pattern: https://zouzoucrochet.com/spiral-star-doily-free-crochet-pattern/  
4. Snowflake crochet pattern: https://irarott.com/blogs/free-patterns/christmas-snowflakes-crochet-pattern 

Millions of people across the US recently got their first view of the Aurora Borealis, or “Northern Lights”, as the night sky turned a rainbow of unusual colors. When I mentioned the aurora in my last blog post about astrophotography for Valentine’s Day, little did I know that this summer would be such an amazing opportunity to see this colorful phenomenon in action.  In recent months, those of us in Madison, WI have been treated to several beautiful displays of green, red, and purple auroras; and I was able to capture some of them on camera:  

But where do these beautiful colors come from?  

Auroras are caused by charged particles ejected from the sun that travel to earth and interact with our atmosphere. This summer we were at the point in the sun’s 11-year cycle when its magnetic field is most unstable; forming sunspots, flares, and coronal mass ejections when enormous amounts of highly energetic charged particles are hurled into space. When this occurs and the particles head toward the earth, they get caught in our magnetic field and spiral around, concentrating near the magnetic north pole (which is in northern Canada) and magnetic south pole. The auroras form as these charged particles crash into gas molecules in the upper fringes of the earth’s atmosphere – about 100 km (62 miles) above the earth’s surface. And this is where chemistry comes in!

Our atmosphere has a rather constant composition of 78% nitrogen and 21% molecular oxygen (O₂) up until 100 km (62 miles) above mean sea level, an altitude known as the Karman Line. At altitudes higher than the Karman Line, the composition suddenly changes: N₂ and O₂ decrease, and atomic oxygen (O) becomes the main component:

To understand why Auroras form at this height, we need to talk about electron orbitals and spin. Electrons in an atom can have different states or “levels” of different energies. For example, the three most important configurations of the four key electrons in an oxygen atom are shown here as up and down arrows arranged in three different energy levels:

Spectroscopists label the three levels as ¹S,¹D, and ³P.  The meaning of these designations isn’t important here, but each arrangement of electrons has its own unique energy. When electrons change from one configuration to another, they have to absorb or emit energy so that the total energy is conserved. (You may remember this phenomenon from Cathy Murphy’s post about “Electrocuting a Pickle”, as well as my Valentine’s Day post.)

Under normal conditions, most O atoms are at the lowest-energy (most-stable) ³P configuration. But when those charged particles from the sun ionize nitrogen molecules, which then collide with the oxygen in the atmosphere, some of these O atoms are excited up to the high-energy ¹S configuration level by various collisions.  After these O electrons get excited up to the highly energetic ¹S configuration, you’d think they would release their energy (as light!) and jump down to the ¹D or ³P configuration. Instead they get stuck. For complicated reasons having to do with the laws of quantum mechanics, the electrons in each of these configurations can’t easily jump between these different configurations. Spectroscopists call these “forbidden” transitions. But “forbidden” isn’t truly forbidden: these transitions are really just kinetically unfavorable. If the atmospheric pressure is low enough that there aren’t many other molecules around to interact with, then after some time (a few tenths of a second), the electrons in these ¹S atoms will jump down in energy anyway, even though it’s supposedly forbidden, and give off light. And where do we have low pressure with molecules not bumping into each other very much? High up in the atmosphere! When these electrons jump from the ¹S to ¹D configuration they emit light at 557 nm, which is green. So, we have a green aurora.

Once in the ¹D configuration, the electrons still have a lot of energy, but they get stuck again—and stuck even worse than before, because now in order to drop down to the ³P configuration they also have to change the spin of one of the electrons (indicated by the arrows on the diagram). Once again, even though it’s unfavorable, if there is no other way to get rid of its remaining energy, the electron will eventually drop from ¹D to the lowest-energy level (³P) configuration. The energy is emitted as light at 630 nm, which is red. 

But if both red and green are created by oxygen atoms, why do we see red and green coming from different locations in the sky? At altitudes lower than ~100 km above mean sea level (where the pressures are higher), the O atoms get excited, but collisions with other gas molecules jostle the electrons and let them drop to lower configurations without emitting light. When this happens, we say the emission is quenched.

Ultimately the aurora depends on a subtle balance of having enough collisions with N₂⁺ and other species to excite oxygen electrons up to the ¹S configuration, but few enough collisions so that the O atoms emit light instead of being quenched. 

This balance is reached at altitudes near the Karman Line, 100 km (62 miles) straight up.  Green light can be emitted from altitudes of ~ 100 km above mean sea level, but red light is produced at even higher altitudes because the red ¹D-³P emission is more easily quenched by collisions with other gas molecules at lower altitude. So, green light is emitted from lower down in the atmosphere, while red light is only emitted from higher up. 

The auroras sometimes show other colors too, due to emission from nitrogen and other gas molecules. Green and red are the most common, but nitrogen (N₂⁺) in particular can give rise to a beautiful purple color from very high altitudes. Auroras can give off many different colors, and are surely one of Nature’s great spectroscopic spectacles!

When I received my acceptance to the CSN Summer Undergraduate Research Experience (SURE) Program last spring, I was so excited for the opportunity to immerse myself in a whole new field of chemistry research in Dr. Christy Haynes’s lab, and to explore Minneapolis, a city I had never been to before! Coming from a small primarily undergraduate liberal arts college in Massachusetts, I was also very curious about what it would be like to work in a bigger laboratory with graduate students and postdoctoral researchers. Little did I know that amidst learning to synthesize carbon dots, attending group meetings, and conducting many different experiments, I would also be reconnected with a passion that I have held close to heart since I was a young child through the CSN SURE’s SciArt program.

When I was younger, my vision for my future focused on art and writing. Though like many others, my career goals changed depending on the book I was reading, what sport I was playing, and just whatever caught my attention as I was learning more about the world around me. I also loved being outside and observing the simple forms of nature in my backyard, be it butterflies flitting from flower to flower, birds hopping on different branches, or the figures I could make out in the clouds. As I began to doodle these in my spare time, I also started to think more deeply about what I was seeing. I started wondering about the types of insects and plants I saw, and what made them different from each other beyond what I could see with my naked eye. This curiosity led me to further investigate the flora and fauna that surrounded me as I grew up, and eventually as I got older, they became my bridge into the world of scientific research.

(Warning: photos of insects and birds coming up)

When I first heard about the summer SciArt program, I was not sure what to expect. I opened the email about the program and was pleasantly surprised at the open-ended prompt that was given to us by Dr. Semarhy Quiñones-Soto, CSN’s 2024 Scholar-In-Residence.¹ The objective of the program was for research students to “learn about science art/communication, and the importance of effective dissemination skills in the presentation of research findings to a broader audience.” The only restrictions that were given to us were that our projects must include (1) scientific results obtained from our summer research and (2) the importance of studying our assigned research topic. Our art projects were also expected to be scientifically accurate and understandable by a broad audience of scientists from different disciplines and non-scientists. Given this, I was very excited to start diving into my research project, so I could also begin brainstorming ideas for my SciArt project.

My ten-week research project focused on the use of carbon dots for the removal of per- and polyfluoroalkyl substances (PFAS) aka forever chemicals from the environment through a process called phytoremediation. Phytoremediation uses plants to pull contaminants out of the soil or water around them and has already been found to be effective in taking up a small subset of the existing library of 12,000+ PFAS molecules.² Carbon dots come into the picture because they are easily synthesized biocompatible nanoparticles that can act as carriers for PFAS into and throughout plant tissue. In other words, carbon dots have the potential to carry PFAS molecules from soil or water into plants without causing harm to the plants.

For my project, I primarily spent my time understanding the affinity that different types of PFAS have for two types of carbon dots, and how changing conditions (such as pH) would affect these interactions. In addition to this, I also worked to optimize growth conditions for a particular type of aquatic weed called Lemna minor (commonly known as duckweed), and tried to identify critical plant pathways to monitor during PFAS/carbon dot exposure. This meant that a lot of my time was also devoted towards cultivating duckweed and keeping it happy!

As I learned more about my research project, conducting experiments and gathering data, the SciArt project lingered at the back of my mind. I found myself constantly trying to think of ways to translate what I was doing into some form of art that could be understood by anyone without much background knowledge. I realized that in order to think of ways to convey my research, I had to break it down into simpler, more fundamental pieces of information first, such as focusing on how exactly pH affects interactions between carbon dots and PFAS. This process was one that actually helped me understand it better myself!

A few weeks into the SURE program, Dr. Quiñones-Soto hosted a webinar talking about her personal experience with career exploration, and how science communication allowed her to bring together her love for both art and science. She also talked about overcoming the fear of sharing her work with the public, and the unique opportunity that science communication provides in advocating for diverse representation in STEM. As someone who hopes to continue my scientific journey, hearing about Dr. Quiñones-Soto’s experiences inspired me to think of ways to incorporate science communication into my own future. As I progress through my scientific career, I hope to continuously contribute to increasing inclusivity and accessibility to science, particularly through illustration and different forms of media.

My SciArt project took a few different forms as I started conceptualizing ideas. I first thought of making an infographic, since I believed this would be the most efficient way to convey a lot of information if I could organize the elements in it effectively. I started thinking of color schemes, backgrounds, and what information I wanted to include in my infographic — how much detail would be too much? I had the base of my infographic far before I had the data that I wanted to include in it, so I let it sit for a while untouched.

After a few weeks of not looking at what I had drafted, I found that the idea grew stale in my mind, and I itched to make something that felt more engaging and fun. This was when I got the idea to make an animation instead! When I was in high school, I dabbled in making animations for school projects, so I thought why not try it again for my SciArt project? This medium was a little more challenging in terms of organization, since I had to be very intentional about the way I represented different parts of my project. Making an animation also required me to think through my experiments step by step without making the whole process too complicated. This forced me to step back from the day-to-day routine in lab and look at my project as a whole, allowing me to identify the key components of my project required for understanding the bigger picture of my research. Since I would be presenting this at a CSN-wide zoom meeting, I also wanted to make sure that it was short but effective at conveying the core of my project. After sketching out my ideas for the flow of my animation, I began to color and finalize my SciArt project, leading to this short stop-motion animation:

I was very nervous to share my SciArt project at the CSN meeting, since I had never had to watch people actively react to art I made. However, my anxieties were washed away as I received positive feedback and encouragement from different members of the CSN who seemed excited and supported my SciArt project! The CSN SURE Program was not only incredibly valuable in shaping my understanding and perspective of the PhD student experience, but also for helping me realize that there are ways for me to incorporate my love for art as I navigate the world of scientific research. Even more importantly, it reminded me of the importance of making science accessible, inclusive, and fun, in order to reach more people and take away the notion of science as exclusive and incomprehensible! While presenting my work was definitely outside of my comfort zone, I am very grateful that I had opportunity to do so and am looking forward to participating in more opportunities to share the science I love and am involved in in the future!

References

1. Dr. Semarhy Quiñones-Soto is CSN’s 2024 Scholar-in-Residence. https://susnano.wisc.edu/2024/04/01/dr-semarhy-quinones-soto-is-csns-2024-scholar-in-residence/.
2. ITRC: PFAS — Per- and Polyfluoroalkyl Substances. Introduction. https://pfas-1.itrcweb.org/1-introduction/.

With the global population at nearly 8 billion, there is a growing demand for a safer and more sustainable ways of food production. New technologies are constantly being developed to help keep food fresh and flavorful while also enhancing its quality and nutrition. Nanotechnology is playing a big role in many of these innovations!

Nanotechnology in general is any technology that uses engineered particles in the size range of 10^-9 m (a billionth of a meter!). It has great potential to make advances in various aspects of the food industry, including flavor, nutrition, color, packaging, and storage. The application of nanoscience in food comes in two forms: ^1,2

1. Nano inside the food (food additives or processing)
2. Nano outside the food (food packaging)

Nano Inside Food

There are many ways that “nano inside” can be incorporated into the process of transforming agricultural and animal products into food. For example, in nanoencapsulation, one can embed bioactive ingredients into the nanosized capsules to prevent them from exposing to environmental conditions such as high temperatures, oxygen, light, pH variations, and interactions that deteriorate the substances. Nanoencapsulation carries the advantage of having reduced particles sizes in nanoscale with enhanced surface-to-volume ratio, with improved absorption.³

Another example of using nanotechnology in food is nano-scale edible thin films made of food-grade materials. Edible films can protect foods from gases, humidity, and lipids. Such edible films can be made from multiple layers that are 1–100 nm thick and are physically or chemically bonded to the food. They can also improve the texture of foods or carry colors, flavors, nutrients, vitamins, antioxidants, and antimicrobials. Nano-antimicrobials help safeguard the food from deterioration, extending its shelf life. ^4,5  Examples of such antimicrobials are metal and metal oxide nanomaterials. The blog post by Ese Ehimiaghe, “Nanoparticles & Food Part 1: Vitamins” explains in detail how nanoparticles are used in food supplements. For example, lipid nanoparticles are used in oral delivery of drugs to increase drug absorption in the gastrointestinal tract as it improves mucosal adhesion due to their small particle size and increased residence time. Protein nanoparticles are used in foods in the form of casein micelles, which are available in bovine milk and other dairy products.

Titanium dioxide (TiO₂) is one example of a nanoparticle that has been used extensively to enhance food appearance. TiO₂ is an approved food additive with limited use (should not exceed 1% w/w (percent weight of the substance by total weight).⁶ It can also be mixed with silicon dioxide (SiO₂) and/or aluminum oxide (Al₂O₃) with not more than 2% of the total – these particles can be used with nanoencapsulation as one way to incorporate fragrances or flavors into food. SiO₂ is also used for thickening of pastes or as an anticaking agent to maintain flow properties in powdered products.

Nano Outside Food

The use of nanotechnology on the outside of food is related to packaging and food safety ⁷. Food can get contaminated or degraded at multiple stages of the food chain; therefore, safe, nontoxic, cost-effective, good-quality packaging material is key.  Nanomaterials can play a role in packaging through controlling and measuring acidity (pH), temperature, moisture, and freshness. Nanotechnology-driven food packaging can be divided into categories as antimicrobial packing and smart packing through sensing.

Some nano-packaging is antimicrobial because it actively reduces microbial growth. Active nanomaterials like antimicrobials and oxygen scavenging materials can be used in packaging to delay oxidation, microbial growth, and moisture migration in the food. Polyethylene films infused with carbon nanotubes have prevented fungal invasion in Mazafati dates for up to 90 days.⁸

Nanoparticles in food can be either organic or inorganic (molecules based on carbon atoms or not), and this composition along with the different sizes and shapes of the particles impacts what happens to them in our bodies.⁹ Silver, silicon dioxide, iron oxide, titanium dioxide, and zinc oxide are a few examples of inorganic nanoparticles used in food industry. Silver nanoparticles are used as antimicrobial agents in food packaging, chopping boards, storage containers, refrigerators, and health supplements. Zinc and zinc oxide nanoparticles are essential nutrients for human health and hence it is used as an additive in supplements and functional foods for nutrition.  Zinc oxide nanoparticles are also used to prevent food from contamination from harmful bacteria in food packaging.¹⁰ On the other hand, organic nanoparticles are composed of organic substances such as carbohydrates, proteins, or lipids. You can also read our previous blog post “Keeping Our Food Safe – Nanomaterial Style” by Laura Olenick to learn more on how nanomaterials are used for food packaging.

Nano-packaging can also reduce food spoiling by improving the quality of the package itself or by helping to monitor what’s going on inside. Nano has helped enhancing the heat resistance and mechanical characteristics in food packaging materials. It can also help detect changes in food products, such as pathogens growing on the surface. For example, companies including British Airways and Nestlé have reportedly used chemical sensors that quickly detect any color change.¹¹ Nanotechnology can also help food industries prevent contamination through authenticating and tracking the trace features of a food product using nanobarcodes.¹²

Safety of Nano in Food

Although nanotechnology has many benefits to offer the food industry, it is always important to consider possible health impacts of new technologies. There are two main safety concerns on using nanoparticles in food: allergies and heavy metal release. Making sure these materials are safe in food requires a proper detailed understanding of the properties of nanomaterials like size, solubility, surface chemistry, and composition.

The US Environmental Protection Agency (USEPA), National Institute for Occupational Safety and Health (NIOSH), Health and Consumer Protection Directorate of the European Commission (HCPDEC), and Food and Drug Administration (FDA) are a few of the regulatory bodies that have passed guidelines to prevent potential risks posed by food nanotechnology. Nanoparticle toxicity and possible environmental and health hazards need to be thoroughly evaluated. As a research center, part of what the NSF Center for Nanotechnology (CSN) does is investigate and characterize biological responses towards various nanoparticles. Our research helps inform efforts to minimize potential harm by nanoparticles that get released into the environment through industrial and agricultural applications. Another aspect of CSN research that’s relevant to food is exploring the benefits of using nanoparticles to help make plants more resilient and resistant to disease. (You can read “Nanotechnology and Modern Agriculture” or “Why nanoscientists and farmers both care about plant leaves” to learn more about this nano-agriculture work.)

Conclusion

It is crucial to establish a healthy and sustainable food industry, including full research exploration of nanotechnology’s potential positive and negative effects in food. The examples of nanosensors to help control environmental contamination or nano-additives to improve nutrition while enhancing flavor are just the beginning of where the technology could go. With careful research and regulation, I think nanotechnology has great potential to contribute to a safe and sustainable food industry.

REFERENCES

1. Ameta, S. K., Rai, A. K., Hiran, D., Ameta, R., & Ameta, S. C. (2020). Use of nanomaterials in food science. In M. Ghorbanpour et al. (eds.) Biogenic nano-particles and their use in agro-ecosystems (pp. 457-488). DOI: 10.1007/978-981-15-2985-6_24
2. Sekhon, B. S. (2010). Food nanotechnology–an overview. Nanotechnology, science and applications, 1-15. PMCID: PMC3781769
3. Assadpour, E., & Jafari, S. M. (2019). Nanoencapsulation: techniques and developments for food applications. In A. López Rubio et al. (eds.) Nanomaterials for Food Applications (pp. 35-61). DOI: 10.1016/B978-0-12-814130-4.00003-8
4. Pool H, Quintanar D, Figueroa JDD, Mano CM, Bechara JEH, Godínez LA, Mendoza S. (2012) Antioxidant effects of quercetin and catechin encapsulated into PLGA nanoparticles. Journal of Nanomaterials. 1–12. DOI: 10.1155/2012/145380.
5. Mitura KA, Zarzycki PK. (2018) Biocompatibility and toxicity of allotropic forms of carbon in food packaging. In: Grumezescu AM, Holban AM, (eds.) Role of Materials Science in Food Bioengineering. (pp. 73-107). DOI: 10.1016/B978-0-12-811448-3.00003-6
6. Shi H, Magaye R, Castranova V, Zhao J. (2013) Titanium dioxide nanoparticles: a review of current toxicological data. Particle and Fibre Toxicology. 10:1–33. DOI: 10.1186/1743-8977-10-15.
7. Kaur, R., & Kaur, K. (2024). Scope of Nanotechnology in Food Packaging. In  M Goyal et al. (eds.) Advances in Sustainable Food Packaging Technology (pp. 135-160). DOI: 10.1201/9781003395249.
8. Asgari, P., Moradi, O., & Tajeddin, B. (2014). The effect of nanocomposite packaging carbon nanotube base on organoleptic and fungal growth of Mazafati brand dates. International Nano Letters, 4, 98. DOI: 10.1007/s40089-014-0098-3
9. McClements DJ, Xiao H. (2017) Is nano safe in foods? Establishing the factors impacting the gastrointestinal fate and toxicity of organic and inorganic food-grade nanoparticles. NPJ Science of Food. 1, 6. DOI: 10.1038/s41538-017-0005-1. 
10. Sirelkhatim A, Mahmud S, Seeni A, Noor HMK, Ling CA, Bakhori SKM, Hasan H, et al. (2015) Review on zinc oxide nanoparticles: antibacterial activity and toxicity mechanism. Nano-Micro Letters. 7:219–242. DOI: 10.1007/s40820-015-0040-x.
11. Manufacturing & Logistics IT blog (2023) Nanotechnology for food packaging from 2023 to 2033 – Industry expected to increase 15% as a result of developments in material science and technology. Retrieved from https://www.logisticsit.com/articles/2023/03/06/nanotechnology-for-food-packaging-from-2023-to-2033-%E2%80%93-industry-expected-to-increase-15-as-a-result-of-developments-in-material-science-and-technology
12. Nam J.M, Thaxton C.S, Mirkin C.A. (2003) Nanoparticle-based bio-bar codes for the ultrasensitive detection of proteins. Science. 26, 301(5641):1884-6. DOI: 10.1126/science.1088755

In the 17th century when alchemy was at its height, many scientists were convinced that they could use science to turn more ordinary substances into gold. It was a time of transformation and potential discoveries. Even though the alchemists failed in their quest, I have become an adamant advocate of a different form of alchemy: using artistic expression to transform abstract scientific concepts into a visual medium. And I work specifically with nanoparticles, which are too small to see, so that has to count for something!

My artistic journey so far

I have been drawing since a very young age, typically depicting the real or fictional worlds around me, like scenes from Phantom of the Opera or characters from comic books. And once I got into science, I never left my need for creative expression behind, though for a while my artistic pursuits were separate from my science. In middle school I was told not to print my art on shirts for the annual holiday fair because no one had ever sold their art like that and teachers thought no one would purchase from me. Fortunately, I ignored them, learned how to iron on my own designs to cut costs, and was the first vendor at the fair to sell out my stock. Later I helped design a logo for that same middle school, which ended up being the mascot used on clothes and the website. In high school, I was the President of a t-shirt graphic design club and I went on to design the senior shirt, and during my undergraduate studies I was merchandise/design officer in my pre-health sorority.

Some of my first memorable exposures to how artists can illustrate scientific concepts came from a Japanese graphic novel and animated series by Akane Shimizu known as Cells at Work. The series personified elements of the human body to help explain the science behind their function, and that concept of finding different ways to explain science in a visual medium really stuck with me. The depictions of macrophages and platelets in Cells at Work came back to me as I learned about those concepts in college. Then in my junior year I entered a chemistry simile contest called the Sweeney Award in honor of the late chemistry professor Michael A Sweeney. I was initially satisfied with finding a creative method to explain a chemical concept, but instead of just entering a written simile, I included a small cartoon to further cement my point.

Art in Chemical Education

Visually creating a story has always helped me learn new and difficult material. When I struggled to learn multiplication tables as a kid, I would often assign personalities to numbers and visualize them moving on my page into the right answer. In biochemistry class I created colorful diagrams illustrating different metabolism pathways customizing them to get a better idea of where proteins and enzymes were coming and going. That year I had multiple classmates ask for my pathway diagrams, even some who took biochemistry after me. Putting pen to paper (or nowadays stylus to tablet), I have been able to understand and better remember scientific concepts than I would with words alone. 

Using visual storytelling can be a matter of practicality when we’re communicating about things that are too small to see with the naked eye. How else can we understand things like two individual atoms reacting together to create new molecules? That is why in chemistry there are so many different methods of visually depicting reactions and molecules. Chemists understand that a visual medium is needed to further depict and comprehend what is going on at the molecular level. 

Leaders in chemical education urge instructors to take a more hands-on, interdisciplinary approach that generates more excitement about learning abstract concepts in new and exciting parts of the field.¹ For many students, science can seem hidden behind complicated terminology, and chemical reactions specifically are often invisible, making them hard to access. In a study comparing art-based learning and concept-based learning of chemistry in high school students, the art-based learning students showed better understanding of the material after creating art using chemistry and explaining the concept behind it. An important aspect to note about the study was that not only did the students learn better with interdisciplinary learning, but they enjoyed it more.²

Sharing Science with a Broader Audience

But what if the creativity of visual depictions could be taken to another level to illustrate higher level chemistry and to an even larger audience? Steve Jobs in 1994 said, “The most powerful person in the world is the storyteller. The storyteller sets the vision, values and agenda of an entire generation that is to come.”³ I believe that breathing more life into scientific concepts and approaching science education from more of a storytelling and artistic perspective can make an enormous impact. Art can help spread the concepts and joys of science to a broader community, which has inspired me to create a number of pieces illustrating my research, and in this blog post I want to share a few of the ones most focused on nanotechnology.

These pieces stem from wanting to create all different types of art while also following a path involving abundant scientific learning and research. Throughout the process of researching and developing my undergraduate research thesis, I created pieces of art that reflected what I was studying on the nanoscale. My aim was to create pieces that would use metaphor to explain concepts that occur on the nanoscale, to bring an invisible science more into the visible scale. The prevailing theme of all the pieces is “NanoParticles within Your Grasp”. There is a continuity across the pieces showing different hands involved in metaphorical connections to concepts relating to nanoparticles. The hands are either surrounding or involved in the explanation of nanoscience. I wanted to take the invisible abstract chemistry behind nanoparticles and make them look attainable. It is also a reference to how I have always enjoyed a more hands-on approach to education and being able to experience science to better understand it. These drawings are a hands-on approach to learning, similar to how one can see reactions happening in a lab or hold a molecule with a physical 3D ball and stick modeling kit that students often use during organic chemistry courses. One cannot physically hold a concept or pick up a singular nanoparticle, but I aimed to use the transformative power of illustrations and analogies to hopefully help people “grasp” the science mentally. For many of the pieces I left the hands devoid of color so anyone could imagine it was their hands gripping the abstract science of nanoparticles.

NanoParticles within Your Grasp

Treasure Trove of Shapes and Sizes: Nanoparticles can be synthesized in many different shapes and sizes, and this work shows them mixed all together in one handful[4]. The shapes and surfaces of a nanoparticle are integral when it comes to its reactivity and general properties. It is what helps make them unique. Creating and morphing nanoparticles into specific shapes changes how the particles interact with light, otherwise known as optical properties. Nanoparticle shape also affects reactivity in their solution environment; for example, high-curvature nanorods and nanostars lose electrons faster in a reaction than low-curvature nanosheets. The shape can also affect the nanomaterial’s interaction with proteins ⁴. Shape can be changed by carefully changing the conditions in which particles are formed. By synthesizing different shapes of the nanoparticles, researchers take advantage of all these different shape-dependent properties for research and technology. The reactivity of a nanoparticle is also affected by its shape, more specifically the flaws found in the internal geometry of a crystalline solid known as its crystallographic defects. When the crystalline structure contains a defect, it generates irregular arrangements on the crystal surface. The reactivity itself changes proportionally to the number of defects, because defects may contain incomplete bonding, which induces higher reactivity.⁵

Moody Influences

Shape isn’t the only thing about nanoparticles that can be influenced during their formation. The pH (or acidity) of the solution during the formation of gold nanorods, for example, can specifically vary the optical properties. When the nanorods are prepared in a more acidic solution, they absorb lower wavelengths of light and end up looking more red, while a more basic pH produces a shift into absorbing a higher wavelength so the solution appears more blue ⁶. The influence of nanoparticles by their environment can change many aspects of their properties like what kind of microenvironments are created on their surface. This reminds me of how mood rings change depending on the wearer’s “mood,” which inspired this artwork. Each person is a solution/environment creating their own unique influence on the color of the ring. (The color of mood rings is actually based on body temperature, but as a child I genuinely thought I could change the color based on my moods because my friends would have different colors than me!)

Ratios from Bitter to Sweet

This piece illustrates the varying surface-to-volume ratios for atoms of varying diameters nanoparticles using the metaphor of rims of ceramic coffee cups. One of the reasons nanoparticles are so highly reactive is that they have a high ratio of surface atoms relative to interior (non-surface) atoms. That means proportionally there are more atoms on the surface of a nanoparticle than on the interior as compared to a larger particle of the same material. The higher reactivity can lead to instability, which facilitates its ability to combine with other atoms[5]. In the case of this metaphor, the surface atoms are equivalent to the ceramic cup and the inner atoms are represented by the coffee itself. This is similar to looking at a cross sectional view of a spherical nanoparticle. The smaller espresso coffee cup has a higher ratio of rim to coffee, while the larger cappuccino cup has a higher coffee-to-rim ratio. Essentially, the different coffee sizes will have similar thickness of their cup material, but as the coffee order changes the volume of the drink changes much more than the surface of the cups. Nanoparticles are like the tiniest possible espresso cups, while “bulk” particles are more like the big cappuccino mug.

The Light Within Your Grasp

One thing you may have heard about silver nanoparticles is that they are anti-microbial – this feature is used within a variety of commercial products. Similar to gold nanoparticles, silver nanoparticles also have interesting optical properties (you can find a more in depth explanation here). These optical properties can be influenced by factors such as nanoparticle diameter and/or shape. You may notice that the colors used in the art piece don’t look like a classic rainbow; instead, I used the Localized Surface Plasmon Resonance spectrum (LSPR) from a study that was able to produce twelve colloidal silver nanoparticles across the rainbow spectrum⁶.  The Light Within Your Grasp depicts how the varying diameters of nanoparticles can shift the wavelengths and in turn shift the color of solution produced. As the diameter of the nanoparticle increases so does the wavelength. This is one of the first unique things I learned about nanoparticles my freshman year of college and it has stuck with me ever since. It is the initial nanoparticle property that inspired it all.

Artistic inspirations

I am far from being a pioneer of the interdisciplinarity of depicting science with art. Scientists and artists have inspired each other’s works throughout history, and, in some cases, there were no clear distinctions between the two. Galileo studied art to accurately depict what he saw in his telescope; Picasso used his art to develop a scientific approach to his art, like with cubism.⁷ There are also many modern examples of artists turned scientists, scientists promoting art, or the two fields occurring in tandem. A few of my favorites include:

• Dr. Cathy Murphy (a CSN faculty member!), used her background as a chemist to introduce interdisciplinary science and art programs. Cathy Murphy is an American chemist who teaches at University of Illinois Urbana-Champaign. Murphy discussed multiple details about her projects in an interview published on the Sustainable Nano Podcast. Murphy explains how she started a program to have artists and scientists explain their work to each other. The STEM students got much better at explaining science concepts to well educated people who did not specialize in science.⁸
• Kate Nichols was the first artist in residence in the Alivisatos Lab at UC Berkeley. When beginning her work with nanoparticles, Nichols was inspired by the sensitivity of light of silver used in photography, and took the phenomenon further into the nanoscale. She leveraged subtle changes in the nanoparticles and their environment to completely transform a piece. Nichols mainly harnesses the optical properties of nanoparticles and uses them to her advantage to create unique works of art, all while using science.⁹
• Corrine Takara took an interdisciplinary approach from an early age as an educator, artist and engineer. Takara is based in Honolulu and identifies as an artist and STEAM educator. Much of her work involves bringing in voices and conserving heritage while also having artworks collide with science. Takara believes that her interdisciplinary work can bring in the voices of non-scientists into science. Takara has said that when looking at the role of art in science she wanted to expand science spaces and what is considered science. She talks about how science is traditionally an isolated space but it can be improved by bringing in more voices.¹⁰

As I’ve learned about nanoscience and nanotechnology, I was inspired by my own desire to create and followed the example of Kate Nichols, Dr. Cathy Murphy, and Corrine Takara. I aim to use art to interpret nanoparticle properties through visual metaphors of nanoscale phenomena. The theme of these is “Nanoparticles within Your Grasp,” using hands to either surround or explain nanoscience ideas. The captions in my drawings throughout this piece illustrate and connect these nanoscience ideas to my own life. Art clearly has an important role to play in chemistry and the greater sciences. My hope is that more educators and anyone interested in science are able to see that abstract concepts can be made “visible” with a different approach. No one should be excluded from science due to intimidation or a preconceived notion that it is not for them.

REFERENCES

1. Palermo, A. (n.d.). Future of the Chemical Sciences. Retrieved from https://www.rsc.org/globalassets/04-campaigning-outreach/campaigning/future-chemicalsciences/future-of-the-chemical-science-report-royal-society-of-chemistry.pdf
2. Danipog, D. L., & Ferido, M. B. (2011). Using art-based chemistry activities to improve students’ conceptual understanding in Chemistry. Journal of Chemical Education, 88(12),1610–1615. DOI: 10.1021/ed100009a 
3. Dykes, B. (2024). The Future Of Data Storytelling Is Augmented, Not Automated. Forbes. Retrieved from https://www.forbes.com/sites/brentdykes/2024/02/27/the-future-of-data-storytelling-is-augmented-not-automated/ 
4. Kinnear, C., Moore, T. L., Rodriguez-Lorenzo, L., Rothen-Rutishauser, B., & Petri-Fink, A. (2017). Form follows function: Nanoparticle shape and its implications for nanomedicine. Chemical Reviews, 117(17), 11476–11521. DOI: 10.1021/acs.chemrev.7b00194
5. Huang, T., & Xu, X.-H. N. (2010). Synthesis and characterization of tunable rainbow colored colloidal silver nanoparticles using single-nanoparticle plasmonic microscopy and Spectroscopy. Journal of Materials Chemistry, 20(44), 9867. DOI: 10.1039/c0jm01990a 
6. Smitha, S.L., et al. (2013) Size-Dependent Optical Properties of AU Nanorods. Progress in Natural Science: Materials International, 23, 1: 36–43, DOI: 10.1016/j.pnsc.2013.01.005 
7. Miller, A. I. (2019). The colliding worlds of Art and science. Nature Nanotechnology. 14, 400. DOI: 10.1038/s41565-019-0448-4 
8. Krause, M. (2016, December 22). EP 11. When artists and scientists collaborate. Sustainable Nano Podcast. Retrieved from https://sustainable-nano.com/2016/12/20/ep-11-when-artists-and-scientists-collaborate/
9. Kate Nichols. (n.d.) retrieved from https://www.katenicholsstudio.com/#/looking-glass/
10. Takara, C. (n.d.). Okada design. Retrieved from https://www.okadadesign.com/#/collections/ 

If you’ve read this blog before, you are likely to know what nanoparticles are: bits of matter on the 1-100 nm scale that have unique properties different from bigger sizes of the same material.  But you might not know what we mean when we say “proteomics,” which sounds to me sort of like “proteins” + “Olympics”

Proteomics is actually a combination of the words “protein” and “genomics.”  You might remember that each person’s genome is the sequence of all their genes from the start of the first chromosome to the end of the last chromosome.  And, you might remember that genes are made of DNA, deoxyribonucleic acid. DNA is a polymer (a long molecule) – one strand of it consists of a sugar-phosphate backbone (deoxyribose is the sugar) that has a “base” attached to each sugar. There are 4 bases:  (adenine (A), guanine (G), cytosine (C), thymine (T)).  Thus,  the genome can be described as the order of the all the bases across all the chromosomes in the person’s DNA.  “Genomics” is the study of the genome.

Just like DNA is a polymer, proteins are also polymers. The building blocks of proteins are amino acids, connected to each other by what we call amide or peptide bonds.  There are about 20 naturally-occuring amino acids. So, by analogy with the genome, we say that a list of all the proteins in an organism is its proteome. (Technically the proteome is coded by the genome, since DNA determines which proteins are made by each cell!)

Proteins are the workhorses of biology: for example, the proteins myosin and actin make up muscle, the protein collagen is part of our connective tissue, hemoglobin is the protein that transports oxygen in our blood and makes it red, and so forth.  Insulin is a small protein that functions as a hormone, regulating glucose levels in the blood. But even though we know a lot about how proteins work, figuring out the proteome of an organism is a lot harder than figuring out its genome. This is because proteins are continuously being produced in the body, then they are modified chemically, and in some cases they degrade over time. So although the genome has the DNA codes for all the proteins, it does not tell you how much of them are made and when. On top of that, proteins vary a lot in size: in solution, some are in the size range of nanoparticles (~10-100 nm) and some are far larger (1000 nm, or one thousandth of a millimeter).

So what do proteins have to do with sustainable nanotechnology? In the CSN we have done a lot of theoretical and experimental research about how individual proteins interact with a nanoparticle surface, at a very granular level.  This is because we want to be able to understand a couple of things: first, how a nanoparticle might interact with a protein that is embedded in the membrane of a cell; and second, how a nanoparticle might interact with a protein that is floating around in liquid in or near an organism.  If we understand these two things, we might be able to predict how a nanoparticle might impact live cells: Would it get inside? Stick to the outside? Dissolve and release extra ions to the cell? Clump up and block channels in the cell membrane?

When we put a nanoparticle in solution (for example, dissolving it in water), and expose it to the innards of a cell, we would expect that molecules in the cell might stick to the nanoparticles, depending on the nature of the nanoparticle surface.  For instance, proteins that have an overall positive charge might stick more to nanoparticles that are negatively charged (similar to how magnets of opposite poles attract each other).  But it’s probably even more complicated than that, since most proteins have patches of positive and negative charge from their constituent amino acids that add up to the total net charge of the protein.

In the CSN we recently did a pretty big experiment to analyze all the proteins in a living cell (at least all above the detection limit of our technique) that were bound to some cool nanoparticles we made. The nanoparticles had a magnetic iron oxide core and a thin gold shell, overall about 200 nm in diameter.  We coated the nanoparticles with PVP, a polymer that provides stability in water and has no net charge.

For the cells in the experiment, we got some trout gill cells (trout is a freshwater fish species used for research a lot), the idea being that in the real world fish might take up nanoparticles through their gills. We broke open the cells, and put all the cell innards (technically called cell lysate, which includes a bunch of proteins) in with our nanoparticles.  Then, we centrifuged the nanoparticles down to a pellet, pulled off the proteins that were bound to them, and analyzed which ones had stuck.  We then repeated this experiment, except that instead of centrifuging the nanoparticle-protein mixture, we went in with a magnet to gently retrieve the nanoparticles and their associated proteins.  We expected that there would be a lot more proteins the gentle magnetic way, and that the roughly centrifuged proteins would be a subset of the magnetically-retrieved proteins.

However, we found this:

Each of the numbers you see in the figure tells us how many proteins were detected under various conditions (yes we have the full list). Each number tells how many proteins were detected in that condition, and the overlapping areas show the number of proteins that showed up in more than one category. PE is “protein extract,” which means what we were able to isolate and detect these proteins from the cells without any nanoparticles. C1 and C2 represent the conditions where we incubated the insides of the cell with the nanoparticles and purified the nanoparticles and their associated proteins by centrifugation once and twice, respectively; M1 and M2 represent the conditions where we incubated the insides of the cell with the nanoparticles and then purified the nanoparticles and their associated proteins by magnetic retrieval once and twice, respectively.

What does all this mean? It means that the history of the nanoparticle is encoded in its protein “fingerprint.”  Look at M2:  there are 26 unique proteins we found in that condition that show up nowhere else. Look at C2: there are 14 unique proteins that we found that show up nowhere else in the experiment (above the detection limit for the technique, of course). And what about those 117 proteins in the middle that show up in all samples? That list is interesting: many of them are involved in maintaining the redox potential of the cell, which is an important equilibrium state – when it gets out of balance, the cell can experience oxidative stress. So this collection of proteins might provide a clue for some mysterious observation that many labs report about oxidative stress in cells:  even non-redox-active molecules or nanoparticles seem to generate oxidative stress responses in cells at a certain dose.  How could this work? Well, maybe our data has an answer: if the molecules or nanoparticles are binding the proteins that maintain levels of oxidants and reductants in the cell, these proteins are less available, making the cell “out of tune” and thus generating an oxidative stress response via this indirect mechanism.

As chemists, we always get excited when we know how many molecules are in a certain place at a certain time.  The experiments I just described don’t really tell us anything about time, but they do tell us about where a lot of different proteins end up when they’re placed close to certain nanoparticles.  Adding the dimension of time would make things even more interesting:  it would be super cool to know, for instance, the dynamic nature of an evolving “protein corona” around a nanoparticle as it gets into a cell, moves through the cell, ends up in some subcellular compartment, etc.  We think that knowing the ever-changing surface coating of the nanoparticle as it goes about its business will provide the best predictor of the nanoparticle’s ultimate fate in a biological or environmental context.

REFERENCES

1. Emily J. Tollefson, Caley R. Allen, Gene Chong, Xi Zhang, Nikita D. Rozanov, Anthony Bautista, Jennifer J. Cerda, Joel A. Pedersen, Catherine J. Murphy, Erin E. Carlson, and Rigoberto Hernandez. Preferential Binding of Cytochrome c to Anionic Ligand-Coated Gold Nanoparticles: A Complementary Computational and Experimental Approach ACS Nano, 2019, 13 (6), 6856-6866 DOI: 10.1021/acsnano.9b01622
2. Khoi Nguyen L. Hoang, Korin E. Wheeler, and Catherine J. Murphy. Isolation Methods Influence the Protein Corona Composition on Gold-Coated Iron Oxide Nanoparticles. Analytical Chemistry, 2022, 94 (11), 4737-4746 DOI: 10.1021/acs.analchem.1c05243