PdCu_x Bimetallic Nanoalloys with “Hand‐in‐Hand” Collaboration in POD‐like Activity and “Back‐to‐Back” Confrontation in SPR Effect for Tumor Redox System Control

Abstract In reactive‐oxygen‐species‐mediated tumor therapy, the generation and accumulation of ·OH is highly dependent on peroxidase (POD)‐like enzymatic activities and the antioxidant tumor microenvironment. As noble metal nanoalloys can enhance the POD‐like enzymatic activity by improving electron transfer and upgrading active sites, PdCu_x (x = 0.6–1.2) bimetallic nanoalloys with optimized enzymatic activity, enhanced photothermal conversion efficiency, and altered glutathione (GSH) consumption ability are synthesized by a facile co‐reduction method. The electron transfer between Pd and Cu in the PdCu_x nanoalloys and their new Cu⁺ catalytic centers contribute to a “hand‐in‐hand” collaboration in their POD‐like enzymatic activities, while their photothermal properties remain almost unchanged because of the “back‐to‐back” confrontation occurring owing to the excess Cu produced by the surface plasmon resonance effect. Moreover, the intrinsic GSH consumption of those nanoalloys and heat from their surface plasmon resonance effect tilt the tumor redox steady state. Therefore, the PdCu_0.9 nanoalloy show excellent POD‐like enzymatic activity resulting from a bimetallic catalytic route, which involves electron transfer from electron‐enriched Pd to hydrogen peroxide and heat‐enhanced Cu⁺/Cu²⁺‐coupled Fenton‐like reactions. The synthesized PdCu_x bimetallic nanoalloys can shed light on the mechanism responsible for enhancing the POD‐like activity in nanoalloys and offer a typical model for constructing next‐generation alloy nanozymes.