Enhanced catalytic performance of DNA-templated silver nanosheets doped with gold and platinum

Silver nanomaterials, owing to their excellent catalytic activity, ease of preparation, and low cost, hold significant promise in efficient catalysis. However, precisely regulating the structure of silver-based nanomaterials to enhance catalytic performance remains a key challenge in this field. In this study, we reported a strategy using DNA nanosheets (DNS) as a scaffold: through DNA self-assembly-mediated precise synthesis, silver nanosheets (DNS/AgNCs) were successfully prepared. Subsequently, Au or Pt was introduced into DNS/AgNCs via galvanic replacement, ultimately yielding uniformly dispersed bimetallic nanosheets DNS/Ag@MNCs (M is Au or Pt). Their catalytic performance was evaluated using ultraviolet visible spectra. Notably, the bimetallic DNS/Ag@MNCs exhibited significantly higher catalytic activity than the monometallic DNS/AgNCs, with DNS/Ag@PtNCs showing the best performance. Furthermore, we observed that DNS/Ag@PtNCs generate hydroxyl radicals during peroxidase-like catalysis. Based on this characteristic, a colorimetric sensor for dopamine detection in urine was developed, with a linear range of 0–150 μM and the limit of detection as low as 0.59 μM. This study not only provides a new technical approach for the controllable construction of metal nanostructures but also lays an important theoretical and experimental foundation for designing and developing high-performance silver-based catalysts. • Silver nanosheets (DNS/AgNCs) were successfully synthesized via DNA self-assembly. • Silver-based bimetallic nanosheets DNS/Ag@MNCs were successfully prepared. • DNS/Ag@MNCs exhibited significantly higher catalytic activity than DNS/AgNCs. • A colorimetric sensor for dopamine detection in urine was developed.