Tuning the rate-determining step of uric acid electrooxidation over single-atom-site metal centers for high-performing sensing

A uric acid (UA) electrooxidation-based electrochemical sensing system is of great interest in the field of measurement science and technology; however, its development is greatly plagued by the lack of efficient electrocatalysts, leading to low detection sensitivity. Herein, we report a general method for making a series of metal single-atom catalysts (SACs) on nitrogen-doped carbon (M1-CN, M = Mo, Fe, Ru, Mn, Co, Cu, Pt, Ni) to tune the rate-determining step (RDS) of UA electrooxidation to greatly boost its electrocatalytic performance. We experimentally demonstrate that the Mo1-CN shows the highest electrocatalytic activity for UA electrooxidation among the investigated M1-CN. As a proof-of-concept application, we construct a portable and wireless biosensor for high-throughput detection of disease markers (human papillomavirus-16 [HPV-16]) based on the particular advantage of Mo1-CN in enhancing the UA electrooxidation performance.