Portable electrochemical test strip based on Au/graphene for rapid on-site detection of xylazine in raw milk

Rapid analysis of xylazine (XYL), a type of drug residue in food of animal origin, is essential for on-site dairy quality monitoring. The conventional analytical methods are encumbered by high costs, complicated sample processing, or cumbersome operational requirements. Here, a gold nanoparticles (Au NPs)/reduced graphene oxide (rGO)-modified screen-printed carbon electrode (SPCE) was prepared via a two-step electrochemical reduction process. The excellent electrical conductivity of Au NPs and the large specific surface area of rGO significantly increase the signal intensity in differential pulse voltammetry (DPV) curves. The XYL was specifically recognized via molecular imprinting technology, utilizing methacrylic acid as a functional monomer and ethylene glycol dimethacrylate as a cross-linker. A portable electrochemical test strip based on this SPCE is capable of rapid detection of XYL in the linear range of 0.1–10 5 μg L −1 with a detection limit as low as 0.02 μg L −1 . This test strip benefits from miniaturization and portability, rendering it suitable for prospective real-time, on-site detection requirements.