Lili He 

Vitals

Current Affiliation: University of Massachusetts, Amherst

Age: 34

Ph.D. alma mater: University of Missouri, Columbia

Role model: Christy Haynes, a collaborator at the University of Minnesota, who He says expertly juggles a successful career and a growing family

In a world without chemistry, I would be: “an environmental scientist, chef, or I’d work at an animal shelter.”

Codename: Contaminant Catcher

We’ve all been there: eating something that we think is delicious in the moment, only to be taken down by a full-on intestinal apocalypse an hour or two later. It wasn’t obvious that a pathogen lurked in the food we chowed, just like it’s not obvious when other contaminants such as pesticides and nanoparticles end up on dinner plates.

Regulators, researchers, and the general public are increasingly concerned about these kinds of food pollutants. But it’s not like you can avoid the risk by simply not eating, quips Lili He, a food chemist at the University of Massachusetts, Amherst.

Drawn to using chemistry to study something as fundamental to everyday life as food, He set out during her Ph.D. to find promising analytical technologies to monitor and analyze food contaminants. She struck gold with surface-enhanced Raman spectroscopy (SERS), a technique that uses laser light to detect signals from individual molecules inside a complex sample by observing their vibrational and rotational motions. The method uses metallic nanoparticles to boost weak signals—up to 10,000 times—allowing He to identify minuscule amounts of problematic chemicals among food’s messy mixture of molecules.

Since starting her own labs, He has pioneered a SERS technique for studying the depth at which pesticides can penetrate spinach leaves. Regulators worry that washing the leaves might not be enough to get rid of pesticides, potentially exposing consumers to harmful levels of the chemicals.

He is also developing SERS methods to measure and monitor dangerous bacteria and unwanted nanomaterials in food. Both the U.S. Department of Agriculture and the Food & Drug Administration have put calls out for techniques that can identify nanoparticles that enter food from pesticides, packaging, and food additives, and He wants to prove that SERS is the right choice.

In the long term, He imagines helping to build a miniaturized SERS cell phone add-on that would allow people to look for unwanted pesticides, microbes, or nanomaterials in food. This could put the power to do food safety checks in the hands of concerned consumers.

Research at a glance

Lili He has shown that surface-enhanced Raman spectroscopy (SERS) can be used to monitor food contamination. As shown here, she observes that SERS, which can amplify molecular signals with nanoparticles, tracks the depth of penetration of pesticides such as thiabendazole in spinach, a concern because many people assume pesticides are removed by washing. Credit: Anal. Chem./C&EN

Lili He has shown that surface-enhanced Raman spectroscopy (SERS) can be used to monitor food contamination. As shown here, she observes that SERS, which can amplify molecular signals with nanoparticles, tracks the depth of penetration of pesticides such as thiabendazole in spinach, a concern because many people assume pesticides are removed by washing. Credit: Anal. Chem./C&EN

Three key papers:

“Real-Time and In Situ Monitoring of Pesticide Penetration in Edible Leaves by Surface-Enhanced Raman Scattering Mapping” (Anal. Chem. 2016, DOI: 10.1021/acs.analchem.6b00320)

“Analysis of Silver Nanoparticles in Antimicrobial Products Using Surface-Enhanced Raman Spectroscopy (SERS)” (Environ. Sci. Technol. 2015, DOI: 10.1021/acs.est.5b00370)

“Surface-Enhanced Raman Spectroscopy for the Chemical Analysis of Food” (Compr. Rev. Food Sci. Food Saf. 2014, DOI: 10.1111/1541-4337.12062)

Career paths:

They might be young scientists, but our Talented 12 have already traveled far and wide.

lili_he_map

Watch He talk about her research during a special Aug. 22 Talented 12 symposium held at the American Chemical Society national meeting in Philadelphia.

 

Daniel Fitzpatrick
Juan Pablo Maianti
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