Acetylcholinesterase inhibition-based biosensor for amperometric detection of Sarin using single-walled carbon nanotube-modified ferrule graphite electrode

In this work, highly sensitive acetylcholinesterase (AChE) inhibition-based amperometric biosensor has been developed. AChE was immobilized by cross-linking with glutaraldehyde onto ferrule graphite electrode (FGE) modified with carboxylated single-walled carbon nanotube (cSWCNT). The properties of optimized biosensors are characterized by scanning electron microscopy (SEM), cyclic voltammograms (CVs) and electrochemical impedance spectroscopy (EIS). The synergistic action of cSWCNT/FGE showed excellent electrocatalytic activity with low applied potential for the detection of acetylthiocholine (ACTh). Sarin and diisopropylfluorophosphate (DFP) could be detected up to 25-35 nM and 15-20 nM respectively at 30-40% inhibition level of AChE and followed linearity in wide range concentration. (C) 2012 Elsevier B.V. All rights reserved.