Pesticide detection using a lateral field excited acoustic wave sensor

Although organophosphate pesticides have been widely used in agriculture to control pests, they can have adverse effects on the environment and also enter the food chain causing adverse health effects in humans. Therefore, a need exists to develop a low-cost, robust, sensitive, and portable sensor for organophosphate pesticides. A lateral field excited (LFE) acoustic wave sensor has been developed in which the sensing surface is bare and the external excitation is applied to the reference surface. The LFE sensor is sensitive to both mechanical and electrical property changes in the monitored solution. In the present work, the LFE sensor is used as the sensing platform to detect the organophosphate pesticide, phosmet (C11H12NO4PS2). A polyepichlorohydrin (PECH) polymer film is applied to the sensing surface to detect phosmet in solution. The results show that the PECH-coated LFE sensor displays a nearly linear response to the addition of phosmet with a slope of 20 Hz/ppm and detection limit in the ppb range.