Multi-signal sensor array based on a fluorescent nanozyme for broad-spectrum screening of pesticides

Abstract

Accurate identification of broad-spectrum pesticides remains a challenge for existing rapid detection technologies based on natural cholinesterase. Sensor arrays show excellent promise, but typically rely on increasing receptors to improve sensing dimensionality, which is both cumbersome and imprecise. In this work, inspired by the multiple properties of a fluorescent nanozyme, we constructed a facile and simple sensor array based on the laccase-like activity, peroxidase-like activity, and fluorescent feature of one nanozyme (Cu-BDC-NH2). In the presence of pesticides, they produced differential positive responses and could be captured by linear discriminant analysis and hierarchical clustering analysis. Thus, different pesticides belonged to organophosphates, carbamates, organochlorines, pyrethroids, sulfonylureas, and diphenyloxazolines, respectively, have been successfully discriminated at 1 – 100 μg/mL. The differentiation of cross-contamination at different concentrations and compositions further validated the sensing performance. More importantly, they demonstrated strong immunity to interference as well as high feasibility for recognizing pesticides in fruits and vegetables, and performed precise identification for blind samples. Therefore, the sensor arrays provided a novel and reliable solution for broad-spectrum pesticide screening, which not only bridged the gap of existing rapid detection methods, but also opened up a new way for food safety regulation.