My research focuses on development and applications of the most advanced and innovative analytical techniques in solving the critical and emerging issues in food science. Surface-Enhanced Raman Spectroscopy (SERS) is a combination of Raman spectroscopy and nano-techniques. The use of metallic nanostructure enhances the Raman scattering more than a million times. We have developed various SERS based techniques for food safety, food chemistry, and food bioscience applications. Check out our recently published SERS review paper:
Jinkai Zheng and Lili He*. 2014. Surface-Enhanced Raman Spectroscopy for the Chemical Analysis of Food. Comprehensive Reviews in Food Science and Food Safety. 13 (3), 317-328. http://onlinelibrary.wiley.com/doi/10.1111/1541-4337.12062/abstract
1. Food safety application: Development of rapid detection methods for targets of chemical and biological contaminants in complex food matrices
Food contamination problems have become globalized and are the causes of many health problems and economic losses. There is an increasing need for rapid detection of food contaminants (chemicals and microbes) in foods, as traditional detection methods such as plating for microbes and HPLC-MS for chemicals are usually time-consuming. We have developed various SERS based methods for rapid detection of protein toxins (i.e. ricin), pesticides, melamine, and other chemical and biological contaminates in foods. We have also explored the handheld Raman spectrometer for on-site SERS detection. These projects are supported by US Department of Agriculture (USDA) and Department of Homeland Security (DHS).
2. Food Chemistry applications: Characterization of food components and their interactions
Collaborating with other faculty and food industry in our department, we have developed various novel SERS approaches to study food components and their interactions.
- Bioactive components (i.e. polymethoxyflavones, PMFs) analysis
- Lipid analysis
- Protein analysis
- Molecular interaction analysis
3. Food bioscience applications: Development of a label-free imaging approach to study the cell-drug interactions
Raman mapping technique is a powerful technique that can produce 2-D or 3-D chemical images without using a chemical label. We have been studying on the cellular responses to different bioactive components (i.e. polymethoxyflavones, PMFs) using Raman mapping. Cancer cells responded differently to different PMFs in their biochemistry profiles, which indicates different mode of actions of these PMFs against cancer cells. This study will improve our understanding of the mechanisms of PMFs against cancer cells, which is important to our long-term goal to develop effective natural products-based strategies to inhibit cancers in humans. The imaging approach can be extended to study other cell-drug interactions.