Synergizing polydopamine-modified electrodes with DNA-anchored UIO-66(Zr) MOF for ultrasensitive detection of horsemeat adulteration in camel meat

The escalating economic and ethical concerns associated with camel meat adulteration using cheaper horsemeat necessitate the development of rapid, on-site detection technologies that overcome the limitations of conventional laboratory-based methods. In this study, a portable electrochemical DNA biosensor was fabricated by integrating a polydopamine (PDA)-modified screen-printed carbon electrode (SPCE) with a nucleic acid-functionalized UIO-66(Zr) metal-organic framework (MOF). The PDA coating facilitated stable, covalent immobilization of DNA capture probes through Schiff base reactions, while the UIO-66(Zr) MOF functioned as a high-capacity signal amplifier owing to its large surface area and intrinsic redox activity. This synergistic architecture enabled ultrasensitive detection, achieving a limit of 3.57 pmol/L for horsemeat DNA and 0.5 g/kg adulteration in camel meat blends—significantly surpassing the performance of existing detection methods. The biosensor exhibited excellent specificity by distinguishing single-base mismatches, along with high reproducibility (RSD = 4.12%), operational stability over 15 days, and accurate recovery rates ranging from 91.7% to 112.4% in spiked samples. Its disposable electrode format, cost-effectiveness, and compatibility with portable potentiostats underscore its strong potential for on-site meat authentication. Overall, this work provides a practical and scalable solution to combat meat fraud in resource-limited settings and establishes a versatile MOF-electrode nanoassembly platform for advanced food safety monitoring. • A portable biosensor detects horsemeat adulteration down to 0.5 g/kg in camel meat. • Polydopamine enables stable DNA probe immobilization on screen-printed electrodes. • UIO-66(Zr) metal-organic framework acts as a high-capacity electrochemical signal amplifier. • The sensor distinguishes single-base mismatches with high specificity. • The method offers a cost-effective tool for on-site food authentication.