PAPER BASED ENZYMATIC BIOSENSOR FOR RAPID ON-SITE DETECTION OF ORGANOPHOSPHATE

Organophosphate pesticides are extensively used in agriculture, but their improper use and persistence in the environment can pose significant risks to human health and ecological safety. Rapid, simple, and cost-effective methods for detecting organophosphate contamination are essential, particularly in resource-limited and field settings. This study focuses on the development of a paper-based enzymatic biosensor for the rapid on-site detection of organophosphate pesticides. The sensing platform utilizes the inhibition of acetylcholinesterase (AChE) by organophosphate compounds, which results in a measurable change in enzymatic activity and provides the basis for pesticide detection. A porous paper substrate is employed as a lightweight and disposable sensing matrix, enabling easy sample application and rapid analyte interaction. The proposed biosensor is designed to provide a visual or colorimetric response that can be interpreted directly or quantified using a smartphone-based image analysis system. Key analytical parameters, including enzyme loading, substrate concentration, reaction time, pH, sensitivity, selectivity, detection limit,and response stability, can be optimized to improve sensing performance. The biosensor can potentially detect organophosphate residues in agricultural and environmental samples with minimal sample preparation. Its low material requirements, portability, rapid response, and ease of operation make the proposed platform promising for preliminary field screening of pesticide contamination. Overall, the paper-based enzymatic biosensor represents a practical approach toward accessible, decentralized, and rapid monitoring of organophosphate pesticides.