Inspection of pesticide residues on food by surface-enhanced Raman spectroscopy

摘要

Modern agriculture depends on pesticides to curb infestations, increase crop yield and to produce the quantity and quality of food demanded by today's society. However, potential pesticide residue contamination of food is of critical concern to the food industry and the regulators responsible for health and safety. For example, many pesticides kill insects by attacking the central nervous system, and the use of these pesticides above the EPA set tolerance levels (from 0.1 to 50 ppm) could pose a threat to humans, in particular infants. Unfortunately, rapid, chemical analysis of pesticide residues is unavailable, and only a very small fraction of foods are inspected. The greatest concern is food imported from nations that simply ignore US regulations. In an effort to address this need, we have been developing a simple device to collect residues from food surfaces, perform a rapid chemical separation, and detect and identify pesticides by surface-enhanced Raman spectroscopy (SERS). Capillaries are coated with a metal-doped sol-gel that both separates chemicals and generates SER spectra when irradiated. SERS of pesticides at ppm concentrations, and a preliminary product to aid inspectors is presented.