Enzymatic electrochemical biosensor for glyphosate detection based on acid phosphatase inhibition
Résumé
A novel enzymatic electrochemical biosensor was fabricated for the indirect detection of glyphosate-based acid phosphataseinhibition. The biosensor was constructed on a screen-printed carbon electrode modified with silver nanoparticles, decorated withelectrochemically reduced graphene oxide, and chemically immobilized with acid phosphatase via glutaraldehyde cross-linking.We measured the oxidation current by chronoamperometry. The current arose from the enzymatic reaction of acid phosphataseand the enzyme-substrate disodium phenyl phosphate. The biosensing response is a decrease in signal resulting from inhibition ofacid phosphatase in the presence of glyphosate inhibitor. The inhibition of acid phosphatase by glyphosate was investigated as areversible competitive-type reaction based on the Lineweaver-Burk equation. Computational docking confirmed that glyphosatewas the inhibitor bound in the substrate-binding pocket of acid phosphatase and that it was able to inhibit the enzyme efficiently.Additionally, the established method was applied to the selective analysis of glyphosate in actual samples with satisfactory resultsfollowing a standard method.