Atom-by-Atom Multimetal CuMoP Deposition on Carbon Electrodes for Sensitive Antidiabetic Metformin Electrooxidation

An atom-by-atom ternary Cu-Mo-P nanocomposite was electrochemically co-deposited onto screen-printed carbon electrodes (SPCEs) to form a highly active sensing interface for the determination of metformin (MF). The one-step anodic fabrication yielded a porous, uniformly distributed network of mixed-valence Cu⁺/Cu²⁺ and Mo⁶⁺ centres embedded within a phosphate-stabilized matrix. Comprehensive microstructural and spectroscopic analyses revealed enhanced surface roughness, expanded electroactive area and favourable charge-transfer characteristics. The CuMoP/SPCE exhibited markedly amplified redox activity and proton-coupled electron-transfer behaviour toward MF, enabling sensitive detection with a linear range of 0.99-13.82 µM and a low detection limit of 0.85 µM. Excellent selectivity, stability and reproducibility were achieved, with recoveries of 94.32%-107.23% in pharmaceutical samples and negligible interference from common ions or saccharides. These results demonstrate the synergistic catalytic contributions of Cu, Mo and P in enabling efficient electron mediation, positioning the CuMoP/SPCE robust, low-cost platform for rapid pharmaceutical quality control and therapeutic monitoring.