SBIR Phase I: Development of a portable, sensitive, user-friendly electrochemical biosensor for detecting Pesticide residues

The broader impact/commercial potential of this Small Business Innovation Research (SBIR) project is to develop a portable, faster, cheaper, more sensitive, more consistent user-friendly electrochemical biosensor for detection of organophosphate and carbamate pesticide (OPaC) residues. While OPaC chemicals have greatly improved crop yields, they have also (1) caused accumulation of pesticide residues in the food chain, (2) promoted the generation of pesticide-resistant insects, and (3) contaminated the air, water and soil. OPaC residues, therefore, are a significant public health concern. The proposed sensor will: increase the sensitivity and specificity for monitoring OPaCs (2) reduce costs associated with pesticide monitoring, and (3) improve portability of monitoring devices. Finally, the proposed biosensor technology could be adaptable for analyzing biofluids, making it transformative in monitoring environmental exposures. This Small Business Innovation Research Phase I project proposes to develop a more sensitive, field-deployable electrochemical biosensor for the detection of organophosphate and carbamate pesticide (OPaC) residues. The system’s principle is that OPaCs bind/inhibit the activity of a highly sensitive designer acetylcholinesterase (AChE) enzyme, diminishing a readily detectable electrochemical current. At the system’s core is a novel AChE enzyme more sensitive to OPaC residues than those currently in use. The approach will further optimize the performance of this novel enzyme by rationally designing variants that decrease aggregation and increase/improve thermal stability, core packing, surface polarity, and backbone rigidity. Finally, the approach will enhance OPaC detection sensitivity even further by increasing the surface area of the electrochemical sensory apparatus. Briefly, the procedure is to submerge the sensor into a buffer to acquire and assign baseline data, add test samples to allow any OPaCs to bind to the optimized AChE enzyme on the sensor, add the AChE substrate acetylthiocholine to the sample, and measure electrochemical inhibition. Taken together, this novel biosensor will result in a major shift in the way OPaC analysis is performed and pave the way for reliable, sensitive, and low-cost field analysis. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.