Novel Acetylcholinesterase Biosensor for Detection of Paraoxon Based on Holey Graphene Oxide Modified Glass Carbon Electrode

Holey graphene oxide (HGO) has been synthesized by one step hydrothermal method and applied to construct a highly sensitive acetylcholinesterase (AChE) biosensor. The developed system is characterized by using SEM, TEM, nitrogen adsorption-desorption, Raman, and electrochemical impedance spectroscopy. It is proved that HGO can effectively immobilize AChE and accelerate electron transfer rate. The prepared biosensor AChE/HGO/glass carbon electrode (GCE) shows excellent affinity to the acetylthiocholine chloride (ATCl) with a Michaelis-Menten constant value of 0.23mM. Under optimum conditions, AChE/HGO/GCE can effectively detect paraoxon with a linear ranged from 10 to 45ng/mL and a detection limit of 1.58ng/mL. Furthermore, the prepared AChE/HGO/GCE biosensor demonstrates excellent stability and reproducibility, which provides a reliable method for the detection of organophosphate pesticides. The developed biosensor is used for detecting paraoxon in real samples of lettuce and cabbage and shows a satisfactory recovery.