Synergistic Catalysis in Ni/Pt Dual-Atom Systems for Dynamic Sweat Metabolite Tracking

Wearable electrochemical sensors are pivotal for the real-time monitoring of physiological states; yet, their performance is often limited by the catalytic constraints of single-atom catalysts (SACs). To overcome these limitations, this study reports the synthesis of a nickel-platinum dual-single-atom catalyst (NiSA/CN/Pt) via high-temperature calcination and photochemical fixation. The synergistic interaction between Ni-N₄ and Pt-N₄ sites significantly enhances the electrocatalytic activity toward uric acid (UA) and tyrosine (Tyr). Density functional theory (DFT) calculations reveal that Pt sites facilitate molecular adsorption and optimize Ni electronic environments, thereby accelerating the catalytic kinetics. The fabricated sensor exhibits exceptional performance, with a linear range of 500 nM to 2 mM and a detection limit of 0.20 μM for UA, and a linear range of 5 μM to 1 mM with a detection limit of 4.85 μM for Tyr. Sensitivity values of 0.032 μM μA^-1 cm^-2 (UA) and 0.033 mM μA^-1 cm^-2 (Tyr) were achieved. The sensor patch demonstrated excellent consistency with commercial reagent kits (RSD <4%), enabling accurate detection of sweat metabolites. These results highlight the potential of NiSA/CN/Pt for real-time health monitoring, providing a foundation for advanced sweat biomarker analysis.