Rapid Pesticide Residue Analyzer

In 1999 the FDA reported that as much as 1% of food brought to market may have contained pesticide residues exceeding EPA tolerance levels (sub part-per-million concentrations) set for safe consumption. The uncertainty in this value is due to the long analysis times (hours/sample) that limit the amount of food actually analyzed. Inspectors need an analyzer that can provide comprehensive analysis in minutes to ensure compliance and increase distribution of safe food, as well as animal feed. We propose a surface-enhanced Raman (SER) based analyzer to satisfy this need by detecting pesticide residues on food and feed below tolerance levels in 5 minutes or less. This will be accomplished through the use of a new nanocomposite material (metal-doped sol-gel) that selectively enhances analyte specific Raman signals reversibly and reproducibly. Phase I will employ combinatorial chemistry to coat 96-well micro-plates with varying sol-gel compositions and properties. Each micro-plate well will be screened for chemical selectivity and SER-activity using eight of the most commonly detected pesticides. This series of pesticides also represents several chemical classes. Feasibility will be demonstrated by added pesticides to food samples, and selectively detecting them after minimum sample preparation (e.g. organic extraction).