Single-atom platinum nanocatalyst-improved catalytic efficiency with enzyme-DNA supermolecular architectures

Single-atom catalysts (SACs), a newcomer in the field of nanocatalysis, have sparked tremendous interest thanks to their high atomic utilization, unsaturated coordination environment, and attractive properties. Unfavorably, few studies have focused on the applications of the SACs in the biosensors. Herein, a reliable SiO2-templated strategy was elaborately designed to synthesize single-atom platinum anchored on the surface of hollow cadmium sulfide (HCdS-Pt-1). Experimental results and density functional theory (DFT) calculation showed that the introduction of Pt-1 was helpful for carrier separation and allowed high carrier density. As a proof-of-concept, HCdS-Pt-1 was served as a photoelectmchemical sensing platform to detect biomolecules. To construct such a universal single-atom biosensor, horseradish pemxidase (HRP) and glucose oxidase (GOx) were encapsulated into DNA flowers (HRP&GOx-DF) with the high biorecognition capability. The as-prepared HRP &GOx-DFs could not only improve the thermal stability of the enzyme but also serve as the versatile recognition elements. In our design, HRP&GOx-DFs, enriched by target analyte, would bioetch HCdS-Pt-1 irreversibly, thus resulting in the change of the electrical readout. Expectedly, SACs, combined with DNA nanotechnology, opens new opportunities for protein diagnostics and biosecurity.