Pt–PtTe₂ Nanoparticles with Heterojunction-Based Accelerated Electron Transfer for Efficient Tumor Therapy

Constructing adaptive biomaterials that can overcome rapid carrier recombination and relieve tumor microenvironments such as hypoxia and overexpression of GSH is considered one of the effective strategies for improving tumor therapy. Herein, the Pt–PtTe2 heterojunction was designed for enhancing tumor therapy. Superoxide anion free radicals (•O2–) can be generated through noninvasive in situ ultrasound (US) excitation, mainly since Pt–PtTe2 could produce more electrons and contribute to rapid charge transfer than those of PtTe2, and O2 gains electrons and converts into the •O2–. Pt–PtTe2 features multifunctional nanoenzyme-like activities such as oxidase, catalase, and glutathione peroxidase. Interestingly, Pt–PtTe2 not only catalyzes H2O2 to generate O2 but also oxidizes reducing glutathione (GSH), thereby alleviating tumor hypoxia and amplifying oxidative stress and promoting tumor cell death. Pt–PtTe2 has the desired photothermal-conversion efficiency (50%) under the second near-infrared window (NIR-II) irradiation due to the strong electron thermal effects, further enhancing the efficiency of tumor therapy. This study provides insight into the tumor therapy strategies of an external-energy field-triggered Pt–PtTe2 heterojunction.