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 phosphatase
inhibition. The biosensor was constructed on a screen-printed carbon electrode modified with silver nanoparticles, decorated with
electrochemically 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 phosphatase
and the enzyme-substrate disodium phenyl phosphate. The biosensing response is a decrease in signal resulting from inhibition of
acid phosphatase in the presence of glyphosate inhibitor. The inhibition of acid phosphatase by glyphosate was investigated as a
reversible competitive-type reaction based on the Lineweaver-Burk equation. Computational docking confirmed that glyphosate
was 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 results
following a standard method.