Advances in Active Materials of Enzymatic Electrochemical Sensors for Detecting Organophosphorus Pesticides

Organophosphorus pesticides (OPs) have been widely employed to increase food production and alleviate the increasingly serious food crisis. However, excessive use of these pesticides has seriously affected human health and even caused death due to significant pesticide residues in food. Therefore, enzymatic electrochemical sensors have been developed to monitor OP residues in food. The electrochemical detection performance of these sensors is determined by the physicochemical properties of electrochemical active materials in their active layers. The definition and classification of OPs are first introduced in this review, then the components of enzymatic electrochemical sensors, including electrodes, electrochemical active layer and bioactive enzyme layer, are analyzed in detail. Furthermore, this review emphatically discusses the recent development of enzymatic electrochemical sensors based on various electrochemical active materials: carbon-based, polymer-based, metal-based, metallic compound-based, metal organic framework-based and covalent organic framework-based materials. Finally, probable research directions for developing enzymatic electrochemical sensors with high sensitivity, excellent stability and good reproducibility are outlined to accelerate rapid, effective and low-cost on-site detection OPs in food. This review is expected to provide inspiration for the design and preparation of the high-performance enzymatic electrochemical sensors.