Record number :
Title of article :
Acetylcholinesterase biosensor based on self-assembled monolayer-modified gold-screen printed electrodes for organophosphorus insecticide detection
Author/Authors :
Arduini، نويسنده , , Fabiana and Guidone، نويسنده , , Simone and Amine، نويسنده , , Aziz and Palleschi، نويسنده , , Giuseppe and Moscone، نويسنده , , Danila، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2013
Pages :
From page :
To page :
Abstract :
A mono-enzymatic acetylcholinesterase (AChE) amperometric biosensor for organophosphate detection was developed immobilizing the AChE enzyme via glutaraldehyde on a preformed cysteamine self-assembled monolayer (SAM) on gold-screen printed electrodes (Au-SPEs). The enzymatic activity was monitored measuring the enzymatic product, thiocholine, at an applied potential of +400 mV vs. Ag/AgCl using ferricyanide in solution as electrochemical mediator. The electrocatalytic activity of ferricyanide towards thiocholine was investigated by using Nicholson–Shain method and finding a second order homogenous rate constant ks equal to (5.26 ± 0.65) × 104 M−1 s−1. In order to develop a sensitive biosensor, the effect of cysteamine concentration, duration of SAM deposition and AChE concentration were optimized. Using paraoxon as model compound, the biosensor showed a linear range up to 40 ppb with a detection limit of 2 ppb (10% of inhibition). The biosensor was successfully challenged with drinking water sample demonstrating to be a useful analytical tool for organophosphorus insecticide detection.
Keywords :
Acetylcholinesterase , Self-assembled monolayer , Gold screen-printed electrode , Organophosphate , pesticide
Journal title :
Sensors and Actuators B: Chemical
Serial Year :
Link To Document :