DNA-templated Ag@Pd nanoclusters for NIR-II photoacoustic imaging-guided photothermal-augmented nanocatalytic therapy.

Developing multifunctional nanozymes with photothermal-augmented enzyme-like reaction dynamics in the second near-infrared (NIR-II) biowindow is of significance for nanocatalytic therapy (NCT). Herein, we prepare DNA-templated Ag@Pd alloy nanoclusters (DNA-Ag@Pd NCs) as a kind of novel noble-metal alloy nanozymes by using cytosine-rich hairpin-shaped DNA structures as growth templates. DNA-Ag@Pd NCs exhibit high photothermal conversion efficiency (59.32%) under 1270 nm laser and photothermally augmented peroxidase-mimicking activity with synergetic enhancement between Ag and Pd. In addition, hairpin-shaped DNA structures on the surface of DNA-Ag@Pd NCs endow them with good stability and biocompatibility in vitro and in vivo, and enhanced permeability and retention effect at tumor sites. Upon intravenous injection, DNA-Ag@Pd NCs demonstrate high-contrast NIR-II photoacoustic imaging-guided efficient photothermal-augmented NCT of gastric cancer. This work provides a strategy to synthesize versatile noble-metal alloy nanozymes in a bioinspired way for highly efficient therapy of tumors. This article is protected by copyright. All rights reserved.