Given their stability, ease of preparation, high catalytic activity, and lower cost, enzyme mimetic nanomaterials (nanozymes) represent an emerging class of chemosensors convenient for food safety monitoring. Herein, Ag-MoS 2 nanozyme is reported as an effective peroxidase mimic for colorimetric detection of thiabendazole (TBZ), a pesticide used in the postharvest process of fruits. The synergetic effect of Ag on MoS 2 resulted in an enhanced peroxidase-like activity (45%) that catalyzed the chromogenic reaction between TMB and H 2 O 2 . The nanozyme showed a comparable affinity for TMB (K m = 0.7 mM) with that reported for the natural HRP enzyme. The catalytic reaction resulted in blue color with characteristic absorption maxima ca. 652 nm, signaling the oxidation of TMB. In the presence of TBZ, the intensity of the blue color decreased, indicating the inhibition effect of the pesticide on the peroxidase-like catalytic activity. Rapid colorimetric detection of TBZ down to 0.24 μM was achieved based on its concentration-dependent inhibition effect. The recoveries from spiked fruit matrices were between 98 and 116%. The obtained results showed the developed sensor as a convenient alternative to natural enzymes and other conventional methods for food safety monitoring purposes.

Herein, Ag nanoparticles (NPs) modified MoS 2 (AgÀ MoS 2 ) was applied to the surface of glassy carbon (GC) to produce a robust electrochemical sensor for the detection of thiabendazole, a common antifungal in the post-harvesting of fruits. Cyclic voltammetry studies confirmed thiabendazole exhibited an irreversible, diffusion-controlled process on AgÀ MoS 2 with a two-fold increase in peak current than the pristine MoS 2. A square wave voltammetry was used for the detection of TBZ. The developed sensor exhibited a linear range between 1-10 μM with LOD down to 0.1 μM (S/N > 3). Analysis of TBZ in mango and banana matrices gave a recovery of 91.6-100.4 % indicating the suitability of the sensor for food safety monitoring.