Atomically Dispersed Metal Interfaces for Analytical Chemistry

ConspectusEngineering sensing interfaces with functional nanomaterials have aroused great interest in constructing novel analytical platforms. The good catalytic abilities and physicochemical properties allow functional nanomaterials to perform catalytic signal transductions and synergistically amplify biorecognition events for efficient target analysis. However, further boosting their catalytic performances poses grand challenges in achieving more sensitive and selective sample assays. Besides, nanomaterials with abundant atomic compositions and complex structural characteristics bring about more difficulties in understanding the underlying mechanism of signal amplification. Atomically dispersed metal catalysts (ADMCs), as an emerging class of heterogeneous catalysts, feature support-stabilized isolated metal catalytic sites, showing maximum metal utilization and a strong metal-support interfacial interaction. These unique structural characteristics are akin to those of homogeneous catalysts, which have well-defined coordination structures between metal sites with synthetic or biological ligands. By integrating the advantages of heterogeneous and homogeneous catalysts, ADMCs present superior catalytic activity and specificity relative to the nanoparticles formed by the nonuniform aggregation of active sites. ADMC-enabled sensing platforms have been demonstrated to realize advanced applications in various fields. Notably, the easily tunable coordination structures of ADMCs bring more opportunities to improve their catalytic performance, further moving toward efficient signal transduction ability. Besides, by leveraging their inherent physicochemical properties and various detection strategies, ADMC-enabled sensing interfaces not only achieve enhanced signal transductions but also show diversified output models. Such superior functions allow ADMC-enabled sensing platforms to access the goal of high-performance detection of trace targets and making significant progress in analytical chemistry.In this Account, we provide an overview of recent progress in atomically dispersed metal-involved interfaces in analytical chemistry. The engineering strategies focused on regulating metal centers, integrating multisite synergy, and tuning charge transport pathways are discussed to boost the catalytic activity and specificity of ADMCs as well as expand their multifunctionality. Combined with various transduction models, including colorimetry, electrochemistry, chemiluminescence, electrochemiluminescence, and photoelectrochemistry, ADMC-based sensors achieve efficient detection of diverse analytes. Specifically, the underlying mechanisms of signal transduction are highlighted. Finally, the perspective and challenges of the ADMC-enabled interface for analytical chemistry are further proposed. We hope that this Account will afford significant inspiration toward the design of ADMCs and the decoding of the improved sensing interfaces.