Single-Atom Ru Biomimetic Nanozyme for the Electrochemical Sensing of Hydrogen Peroxide

A rational design of high-efficiency single atoms represents a desirable goal for the construction of efficient electrochemical devices. Nevertheless, their activity is constricted by the exposure of single atoms to reactants. Herein, novel ruthenium (Ru) single atom anchored on graphene frameworks (GFs) that feature interconnected porous structures (defined as Ru SA/GFs) is synthesized through a one-step photoreduction strategy. Ru SA/GFs possess additional structural merits that favor promoting reactant transport and maximizing the efficacy of single atoms, which manifest notable amplified electrocatalytic-reduction activity toward hydrogen peroxide (H2O2) than that of Ru nanoparticles/GFs, indicating the remarkable biomimetic nanozyme-like activity of Ru SA/GFs toward H2O2. Density functional theory (DFT) calculations reveal that Ru SA/GFs with atomically dispersed Ru significantly facilitate the electrochemical reduction efficiency toward H2O2. In addition, a sensitive Ru SA/GFs-based electrochemical sensing platform for the detection of H2O2 with a low detection limit of 0.063 μM is developed and demonstrated. This work not only exploits an innovative approach to synthesize single-atom Ru anchored on GFs for the construction of an efficient biomimetic H2O2 electrochemical sensor but also contributes to the broader utilization of Ru single atom in the advancement of diverse high-performance electrochemical devices.