Nanostructured zinc chromate decorated on halloysite nanotubes for high-performance detection of dimetridazole in food samples

Abstract

The extensive application of veterinary drugs and agrochemicals has emerged as a pressing global issue due to their persistence in the environment and long-term implications for human health and ecosystems. Dimetridazole (DZ), a nitroimidazole compound widely utilised in animal husbandry and poultry, has also drawn substantial concern due to its persistence, bioaccumulation, and toxicological implications, including mutagenic and carcinogenic effects. To meet the demand for effective monitoring strategies, this work proposes a Zinc chromate and halloysite nanotube-based nanocomposite as an electrocatalytic sensing platform for detecting DZ. The spinel ZnCr₂O_4, which exhibits high physicochemical stability, is integrated with HNTs, which provide a high surface area to the nanocomposite. The resulting ZnCr₂O₄/HNT electrode demonstrates enhanced electrochemical performance relative to pristine ZnCr₂O₄, attributable to accelerated charge transfer, greater exposure of active sites, and improved interfacial interactions between DZ and the nanocomposite surface. The ZnCr₂O₄/HNT/GCE sensor achieves a detection limit of 0.0036 μM and a linear concentration range of 0.1–736.4 μM, demonstrating excellent sensing performance for the detection of DZ. Furthermore, the as-constructed sensor exhibits excellent reproducibility and selectivity, with recoveries of 98–99% with relative standard deviation (RSD) values below 4%. The ZnCr₂O₄/HNT/GCE sensor is applied to real sample analysis, including milk and tomato, confirming its practical applicability for food safety and environmental monitoring.