Electro-Immobilization of Acetylcholinesterase Using Polydopamine for Carbaryl Microsensor

A simple and sensitive electrochemical acetylcholinesterase (AChE) biosensor for determination of carbaryl, one of the most commonly used carbamate pesticides, is described. The AChE enzyme was successfully entrapped by a polydopamine–graphene composite on polypyrrole nanowires that modified interdigitated planar platinum-film microelectrodes . The influence of different parameters on the operation of the biosensor was also studied. The selected parameters for the biosensor performance in detecting carbaryl were as follows: applied potential + 0.7 V, pH 7.4 at 25°C. The inhibition of carbaryl was proportional to its concentrations ranging from 0.05 to 1.5 μ g/mL with the detection limit of 0.008 μ g/mL using chronoamperometry. This study provides a promising approach in fabrication of sensitive biosensors for the analysis of carbamate pesticides as well as other hazardous compounds.