Bionic nanozyme arrays for selective identifying and discriminating sulfonylurea herbicides via recognition site mimicry

Sulfonylurea herbicides (SUs) are widely used in agriculture owing to their high herbicidal efficacy and low mammalian toxicity. However, their persistence results in residues that pose potential risks to the environment and human health, making it essential to develop rapid and accurate detection techniques for these herbicides. Herein, we designed bionic nanozymes inspired by the structure of acetolactate synthase (ALS), the primary target enzyme of SUs in plants. Using the ALS cofactor thiamine diphosphate and key binding amino acids (arginine, proline, and tryptophan) as ligands, we synthesized bionic nanozymes that exhibited excellent peroxidase-like activity. SUs significantly enhanced the activity of the bionic nanozymes, and the degree of enhancement varied among different SUs. In contrast, organophosphate pesticides (OPs), carbamate pesticides (CPs), and other tested pesticides did not induce such enhancement. Therefore, we constructed a six-channel colorimetric sensor array and achieved 100% accurate discrimination of five SUs across a concentration range of 1–100 µg/mL. Furthermore, the SUs in the four real grain samples and the blind sample were also accurately distinguished by the array. This study not only provides an efficient method for rapid detection of SUs, but also opens new avenues for the bionic design of nanozymes aimed at the precise identification of specific pesticide molecules in complex matrices.