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.