Ultra-highly sensitive and stable acetylcholinesterase biosensor based on TiO2-NRs and rGO

A highly stable acetylcholinesterase (AChE) sensor based on titanium oxide nanorods (TiO 2 -NRs) and reduced graphene oxide (rGO) for detecting dichlorvos (DDVP) is successfully developed. The sensor adopts a layer-by-layer assembly method to sequentially assemble chitosan (CS)-modified reduced graphene oxide (denoted CS&rGO), gold nanoparticles (Au-NPs), TiO 2 -NRs, and acetylcholinesterase (AChE) on the surface of a glassy carbon electrode (GCE). The catalytic activity, impedance characteristics, material effects, the relationship between the inhibition rate of the sensor and the dichlorvos (DDVP) concentration, interference studies, real sample detection, and storage stability of the sensor were all evaluated using electrochemical characterization. The sensor’s response to DDVP ranged from 2.26 nM to 565 nM, with a limit of detection of 2.23 nM, and it displayed good repeatability, selectivity, and storage stability.