A Microfluidic Biochip for Rapid Screening of Pesticide Residues

This Small Business Innovation Research Phase I project will develop an innovative biochip for rapid screening of pesticide residues in water and food samples. The proposed biochip will be built on BioDetection Instruments' exclusively-licensed patented technology and previous work on biosensors that are based on microfluidics, interdigitated microelectrodes (IMEs), and the electrochemical measurement of an indicator of microorganisms' physiological activity. <P> An inexpensive and robust biomaterial that can sense the relevant bioactivity/toxicity of a class of widely-used pesticides will be immobilized onto the surface of an IME. A cover will be attached to the modified IME with a microfluidic channel exposed to the IME. Physiological activity of the immobilized organism will be monitored in the absence and presence of atrazine, a model pesticide, by electrochemical measurement of the indicator, and the IME signal intensity is expected to be related to the pesticide concentration. <P>One of the primary Phase I goals is to prove the concept by demonstrating the detection of atrazine in less than 10 min with a detection limit of = 1 ppb (= 5 nM). The biochip will have the combined advantages of the biomaterial, microfluidics, and IME measurement such as low cost, high sensitivity, rapid speed, etc.. <P>Contamination of water and food by pesticides and the potential hazard to human health remain major concerns of our society. Current pesticide detection methods such as HPLC, GC, and rapid test kits require sophisticated instruments, skilled personnel, extensive sample pretreatment, expensive bioreagents and/or intensive manual operations, and thus are unsuitable for on-site or routine screenings. Part of the challenge that faces the regulatory agencies and industries is to find better technologies for the rapid detection of low-level pesticide residues. <P>Public Health Relevance: The proposed biochip technology will be a rapid and inexpensive method to screen drinking water, beverages, and food products on-site or on-line for the presence of pesticide residues. Using a network of screening tests followed by confirmatory analysis will assure both producers and consumers that these products are free of dangerous levels of pesticide residues and will enhance the protection and safety of the nation's water and food supply.