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The insufficient exposure sites and active site competition of multienzyme are the two main factors to hinder its therapeutic effect. Here, a phase-junction nanomaterial (amorphous-crystalline Cu x S-Ag 2 S) is designed and prepared through a simple room temperature ion-exchange process. A small amount of Ag + is added into Cu 7 S 4 nanocrystals, which transforms Cu 7 S 4 into amorphous phased Cu x S and produces crystalline Ag 2 S simultaneously. In this structure, the overhanging bonds on the amorphous Cu x S surface provide abundant active sites for optimizing the therapeutic activity. Meanwhile, the amorphous state enhances the photothermal effect through non-radiative relaxation, and due to its low thermal resistance, phase-junction Cu x S-Ag 2 S forms a significant temperature gradient to unlock the optimized thermo-electrodynamic therapy. Furthermore, benefiting from the high asymmetry of the amorphous state, the material forms a spin-polarized state that can effectively inhibit electron-hole recombination. In this way, the thermoelectric effect can facilitate the enzyme-catalyzed cycle by providing electrons and holes, enabling an enhanced coupling of thermoelectric therapy with multienzyme activity, which induces excellent anti-tumor performance. More importantly, the catalytic process simulated by density-functional theory proves that Ag + alleviates the burden on the Cu sites through favorable adsorption of O 2 and prevents active site competition., (© 2024 Wiley‐VCH GmbH.)

A NIR-II light-actuated multifunctional nanoplatform based on ultrasmall CuCo 2 S 4 and Pt nanoparticles is developed for photothermal enhanced nanozyme catalytic and photodynamic therapy. [Display omitted] • CuCo 2 S 4 -Pt-PEG nanocomposites is ultrasmall, which facilitates cellular uptake, and improves the anticancer efficiency. • The nanocomposites have a high photothermal conversion efficiency of 78.46%, and can enhance nanozyme catalytic activities. • The CAT nanozyme activities of Pt enables CuCo 2 S 4 -Pt-PEG to produce more O 2 , and amplify its photodynamic properties. • CuCo 2 S 4 -Pt-PEG can stimulate the immune system to elicit immune response, and inhibited tumor metastasis. The clinical applications of the photothermal therapy (PTT) and photodynamic therapy (PDT) are restricted by the limited tissue penetration depth of excitation light, while the enzyme catalysis therapy is hindered on account of the low treatment efficiency. Herein, we modify artificial nanozyme Pt nanoparticles on the surface of CuCo 2 S 4 nanoparticles to prepare ultrasmall copper-based ternary bimetallic chalcogenides CuCo 2 S 4 -Pt-PEG nanocomposites for PTT/PDT/enzyme catalysis synergistic therapy. The as-fabricated CuCo 2 S 4 -Pt-PEG nanocomposites display peroxidase (POD)-like and catalase (CAT)-like activities, which can catalyze hydrogen peroxide to emerge highly toxic hydroxyl radicals and oxygen, respectively. The integration of Pt nanozyme significantly improves the POD-like and CAT-like activity of CuCo 2 S 4 −PEG that can produce more hydroxyl radicals and oxygen to improve the effects of PDT. Furthermore, the nanocomposites exhibit outstanding photothermal properties derived from the enhanced photothermal conversion efficiency (η = 78.46 %) exposed to 1064 nm NIR-II light irradiation with a low power density (0.8 W cm−2). In particular, the photothermal performance of CuCo 2 S 4 -Pt-PEG significantly enhances the enzyme-like activity. Additionally, the T 1 -weighted magnetic resonance and photoacoustic imaging endow CuCo 2 S 4 -Pt-PEG with the advantages of guiding the treatment process. The synergistic treatment demonstrates significant anticancer treatment efficiency while also elicits immune response that suppressed metastasis. This study could further promote the application of ternary bimetallic chalcogenides in cancer diagnosis and treatment. [ABSTRACT FROM AUTHOR]