A novel trimetallic nanozyme-based three-channel colorimetric sensor array for multiplex pesticides discrimination

The development of highly active and sensitive strategy is of paramount importance for the detection of pesticide residues. Colorimetric sensor arrays have been employed for this need, leveraging their capacity to simultaneously discriminate among multiple pesticides. Herein, a novel trimetallic nanomaterial (PtPd@MnO₂), exhibiting remarkable peroxidase-mimicking activity, was designed and synthesized for the detection and identification of pesticides. Interestingly, the influence of pesticides on the catalytic activity of PtPd@MnO₂ varies across different pH conditions. Capitalizing on this, a colorimetric sensor array was constructed using TMB as a chromogenic substrate in the presence of H₂O₂, which successfully produced colorimetric fingerprints for six representative pesticides. In addition to single pesticide recognition, the platform demonstrated robust capability in identifying pesticides mixtures. Notably, the as-fabricated sensor array proved feasibility in real-sample analysis, capable of discriminating pesticide residues in foods like cherry tomatoes, broccoli leaves, apples, and cucumbers, underscoring its promising potential in food safety monitoring.