Speaker
Description
Monitoring pesticide concentration distribution across farm fields is crucial for precise application and minimizing environmental impact. Rapid, on-site detection of pesticide spray is hindered by lack of field-deployable and easy-to-use sensors that circumvent sample transportation to limited laboratories that possess the equipment needed for detection. Laser-induced graphene (LIG) shows promise in both wettability tuning and electrical conductivity to circumvent the need for field applicable sensors to measure pesticide spray and residue through electrochemical sensors and microfluidics. The LIG is synthesized and patterned on polyimide through a high-throughput CO2 laser process, making it scalable for manufacturing. Our work demonstrates LIG electrochemical biosensors, functionalized with metallic nanoparticles and/or enzymes for detection of various pesticides including a sensor with sensitivity of 5.64 nA µM-1 for the herbicide glyphosate. Glyphosate is a globally applied herbicide, yet it has been relatively undetectable in-field samples outside of gold-standard techniques. Its presumed nontoxicity toward humans has been contested by the International Agency for Research on Cancer, while it has been detected in farmers’ urine, surface waters and crop residues. The sensor shows minimal interference from the commonly used herbicides and insecticides: atrazine, 2,4-dichlorophenoxyacetic acid, dicamba, parathion-methyl, paraoxon-methyl, malathion, chlorpyrifos, thiamethoxam, clothianidin, and imidacloprid. Sensor function is further tested in complex river water and crop residue fluids, which validate this platform as a scalable, direct-write, and selective method of glyphosate detection for herbicide mapping and food analysis. We have also collaborated on the development of portable potentiostats for field deployable studies with researchers at Iowa State University. A portable potentiostat with a user-friendly interface was developed for remote operation, achieving up to 97% accuracy compared to commercial benchtop devices. This innovative system advances precision agriculture by enabling the monitoring and mapping of pesticide distribution, potentially reducing environmental impact, enhancing crop management practices, and contributing to the sustainable and efficient use of agrochemicals in modern agriculture.
