Sensitive biosensing of neurotransmitter: 2D material wrapped nanotubes and MnO2 composites for the detection of acetylcholine

Abstract

Acetylcholine (ACh) is a neurotransmitter which plays central role in transmitting information between nerve - skeletal intersection and neurons present in the spinal cord. Presently, there are few conventional techniques for the detection of ACh however they have certain limitations including requirement of trained technicians, time consumption and low sensitivity. Therefore, it is necessary to develop new methods based on emerging nanotechnology for detecting ACh in real samples. The ACh biosensor was fabricated with the co-immobilization of acetylcholinesterase (AChE) and choline oxidase (ChO) over the Au-electrode coated with nanocomposite layer of multi-walled carbon nanotubes (MWCNT)-manganese oxide (MnO2)- reduced graphene oxide (rGO). Characterizations of the nanocomposites were accomplished by Scanning Electron Microscopy (SEM). The cyclic voltammetry (CV) technique was adopted for the testing and optimization of the developed biosensor. The observation for current in proportion to various ACh concentrations show a linear relation ranging between 0.1–100 μM. The detection limit (LOD) of the biosensor was obtained up to 0.1 μM.