A novel label-free electrochemical immunosensor based on Ce-MOF@AgAuNPs for highly sensitive detection of monensin

A novel electrochemical immunosensor for the sensitive detection of monensin (MON) was developed. The sensor platform utilized anti-MON monoclonal antibodies and a nanocomposite (Ce-MOF@AgAuNPs), composed of cerium-based metal-organic frameworks decorated with silver-gold nanoparticles. The physicochemical properties of the Ce-MOF@AgAuNPs nanocomposite were investigated using transmission electron microscopy, energy dispersive X-ray, UV–Vis spectrophotometry, and fourier transform infrared techniques. The stepwise fabrication process and electrochemical performance of the immunosensor were investigated through electrochemical impedance spectroscopy and cyclic voltammetry. The sensor exhibited excellent analytical performance for MON detection, with a wide linear response range from 0.05 to 250 ng mL −1 and a low LOD of 0.008 ng mL −1 . Additionally, the immunosensor exhibited high accuracy, with recovery rates ranging from 97.4% to 103.2% in chicken liver and 96.0%–104.7% in milk. This developed immunosensor shows great potential for food safety applications, demonstrating high specificity, stability, and reproducibility in the detection of MON.