Nanozymes paper−based analytical device for the detection of organophosphate pesticides in fruits and vegetables
Supattra Arsawiset, Sompong Sansenya, Siriwan Teepoo
Abstract
In this work, copper oxide nanoparticles (CuONPs) nanozymes paper-based analytical device was designed for the rapid detection of organophosphate pesticides in fruits and vegetables. The paper-based analytical device was modified with silica oxide nanoparticles to enhance the assay sensitivity. CuO nanozymes displayed peroxidase-like activity and catalyzed the oxidation of o -dianisidine in the presence of H 2 O 2 from the hydrolysis of acetylthiocholine . This results in the formation of a brown−colored product. In the presence of organophosphate pesticides such as malathion , acetylcholinesterase activity was inhibited, resulting in reduced color intensity production, and which was measured with a smartphone. The proposed nanozymes paper-based analytical device exhibited a good linear detection range (0.1–5 mg L −1 ), a low detection limit of 0.08 mg L −1 , and the analysis time was only about 10 min for malathion detection under optimal conditions. Moreover, the CuONPs had excellent catalytic activity and higher stability than peroxidase . Finally, this device can be applied to detect organophosphate pesticides in fruits and vegetables with rapidity, accuracy, portability, and ease of handling in the field.