Oxime-Functionalized Polydiacetylene Nanocomposite Sensor for Equipment-Free On-Site Detection Of Organophosphate Insecticide Chlorpyrifos Ethyl

Abstract A novel oxime-incorporated polydiacetylene-functionalized molecule (PCDA-OX) was synthesized for real-time, rapid, and selective detection of the organophosphate insecticide chlorpyrifos ethyl, which is widely used in agricultural fields globally. Nanocomposites containing PCDA-OX molecules were fabricated within a cellulose acetate matrix using an electrospinning technique, followed by chemical hydrolysis to obtain regenerated cellulose-based sensing materials. Comprehensive characterization was performed using scanning electron microscopy, nuclear magnetic resonance, Fourier-transform infrared spectroscopy, and an Instron tensile tester. Exposure to the chlorpyrifos ethyl triggered an instantaneous chromatic transition from blue to red/pink, enabling naked eye detection without instrumentation. The proposed sensor exhibited high selectivity against other classes of insecticides and achieved a limit of detection of 40 mmol. The sensing platform offers a simple, rapid, and field-deployable approach for organophosphate monitoring, offering a promising strategy for protecting human health and saving lives.