CoN4/RuP dual-site catalysts with superior hydrogen evolution reaction activity for sensitive biosensing

Hydrogen evolution reaction (HER) catalysts have attracted increasing attention as signal amplifiers in electrochemical sensing, but their practical use in analytical detection is still hindered by sluggish catalytic kinetics, particularly in neutral media. Herein, a dual-center CoSA/RuP catalyst is developed by integrating atomically dispersed CoN 4 sites with RuP nanoparticles, delivering enhanced HER activity and durability. Experimental results together with density functional theory calculations show that the interfacial Co-Ru interaction regulates the local electronic structure and provides a favorable pathway for interfacial hydrogen transfer, which facilitates HER-related intermediate conversion and enhances HER kinetics. Based on this HER-amplified process, a CoSA/RuP-driven electrochemical sensing platform is constructed for acetylcholinesterase detection. The biosensor achieves a broad linear range of 1-1000 mU mL −1 and a detection limit of 0.53 mU mL −1 . The platform is further applied to organophosphorus pesticide detection through AChE inhibition. These findings highlight the feasibility of HER-amplified electrochemical sensing.