Acetylcholinesterase Immobilized on Au Surfaces for the Detection of Organophosphate Pesticides: A Model for Enzyme-Based Biosensors
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Updated: Sep 10, 2026

Bridging the Bio-Electronic Interface with Biofabrication
Published on: June 6, 2012
Diane E Madeksho1, Lauren J Webb1,2,3
1Department of Chemistry, The University of Texas at Austin, Austin, Texas78712-1224, United States.
Abstract:
Immobilized enzymes offer several advantages for biosensing, including high specificity and reusability, but their practical implementation is often hindered by a significant loss in substrate binding or other catalytic activity upon immobilization. In this work, we have demonstrated a simple and robust method for the detection of organophosphate pesticides (OPs) using acetylcholinesterase (AChE) directly adsorbed on bare Au surfaces. Our sensor exhibits a remarkably low limit of detection (149 pM) for paraoxon (POx), a model organophosphate, retains ∼70% of its activity after multiple cycles of inhibition and reactivation, and maintains functionality in complex matrices such as orange juice and soil runoff. This work represents a significant advance in immobilized enzyme-based sensing and establishes a model for the development of biosensors using similar immobilization strategies for other enzymes.
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