Acetylcholinesterase Immobilization on ZIF-8/Graphene Composite Engenders High Sensitivity Electrochemical Sensing for Organophosphorus Pesticides

Abstract

A sensitive and flexible detection method for organophosphorus pesticides (OPs) detection is a crucial request to avoid their further expanded pollution. Herein, an acetylcholinesterase (AChE) electrochemical sensor, based on the co-modification of ZIF-8 and graphene (GR), was constructed for the detection of OPs. ZIF-8/GR composite can provide a stable and biocompatible environment for the loading of AChE and can accelerate the chemical reaction on the electrode surface. After optimization, the linear detection range of the constructed AChE-CS/GR/ZIF-8/GCE sensor for ICP was 0.5–100 ng/mL (1.73–345.7 nM), and the limit of detection was 0.18 ng/mL (0.62 nM). Moreover, high sensitivity and high specificity of the sensor were also achieved in actual cabbage and tap water samples. Therefore, it has great potential for the application of organophosphorus pesticide residue analysis.

Keywords

• electrochemical biosensor
• metal-organic framework
• graphene
• acetylcholinesterase
• isocarbophos