Electrochemical immunosensor based on broad-spectrum antibodies for detection of organophosphorus pesticide residues in fruits and vegetables

• Broad-spectrum antibody enables multiplexed organophosphorus pesticide detection. • PANI/Co₃O₄ nanomaterial-based sensor achieves high sensitivity and stability. • Provides a rapid, portable alternative to traditional laboratory methods. • Facilitates efficient on-site screening of pesticide residues in produce. Diethoxythiophosphate organophosphorus pesticides are widely used in agricultural production. However, excessive pesticide use leads to the presence of pesticide residues in agricultural products, thereby affecting their safety and posing a threat to consumer health. Traditional pesticide detection equipment is characterized by high personnel requirements and is expensive and time-consuming to use, which is not conducive to the rapid detection of pesticide residues in practical applications. Although the existing electrochemical immunosensors are able to provide efficient, rapid, and portable detection of pesticide residues, they can only recognize certain residue types and cannot realize simultaneous detection of multiple residues. Therefore, an electrochemical immunosensor was developed based on PAIN/Co 3 O 4 as the substrate material to specifically identify diethoxyphosphorothioate organophosphorus pesticides by employing broad-spectrum organophosphorus antibodies as the identification element. Detection was carried out based on the specific recognition element of each pesticide in order to achieve simultaneous detection and rapid screening of a variety of diethoxyphosphorothioate organophosphorus residues.