Single-Atom Indium Boosts Electrochemical Dopamine Sensing

A rational design of high-efficiency electrocatalysts and thus achieving sensitive electrochemical sensing remains a great challenge. In this work, single-atom indium anchored on nitrogen-doped carbon (In1–N–C) with an In–N4 configuration is prepared successfully through a high-temperature annealing strategy; the product can serve as an advanced electrocatalyst for sensitive electrochemical sensing of dopamine (DA). Compared with In nanoparticle catalysts, In1–N–C exhibits high catalytic performance for DA oxidation. The theoretical calculation reveals that In1–N–C has high adsorption energy for hydroxy groups and a low energy barrier in the process of DA oxidation compared to In nanoparticles, indicating that In1–N–C with atomically dispersed In–N4 sites possesses enhanced intrinsic activity. An electrochemical sensor for DA detection is established as a concept application with high sensitivity and selectivity. Furthermore, we also verify the feasibility of In1–N–C catalysts for the simultaneous detection of uric acid, ascorbic acid, and DA. This work extends the application prospect of p-block metal single-atom catalysts in electrochemical sensing.