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Non-invasive precision tumor dynamic phototherapy has broad application prospects. Traditional semiconductor materials have low photocatalytic activity and low reactive oxygen species (ROS) production rate due to their wide band gap, resulting in unsatisfactory phototherapy efficacy for tumor treatment. Employing the dye-sensitization mechanism can significantly enhance the catalytic activity of the materials. We develop a multifunctional nanoplatform (BZP) by leveraging the benefits of bismuth-based semiconductor nanomaterials. BZP possesses robust ROS generation and remarkable near-infrared photothermal conversion capabilities for improving tumor immune microenvironment and achieving superior phototherapy sensitization. BZP produces highly cytotoxic ROS species via the photocatalytic process and cascade reaction, amplifying the photocatalytic therapy effect. Moreover, the simultaneous photothermal effect during the photocatalytic process facilitates the improvement of therapeutic efficacy. Additionally, BZP-mediated phototherapy can trigger the programmed death of tumor cells, stimulate dendritic cell maturation and T cell activation, modulate the tumor immune microenvironment, and augment the therapeutic effect. Hence, this study demonstrates a promising research paradigm for tumor immune microenvironment-improved phototherapy. Through the utilization of dye sensitization and rare earth doping techniques, we have successfully developed a biodegradable bismuth-based semiconductor nanocatalyst (BZP). Upon optical excitation, the near-infrared dye incorporated within BZP promptly generates free electrons, which, under the influence of the Fermi energy level, undergo transfer to BiF 3 within BZP, thereby facilitating the effective separation of electron–hole pairs and augmenting the catalytic capability for reactive oxygen species (ROS) generation. Furthermore, a cascade reaction mechanism generates highly cytotoxic ROS, which synergistically depletes intracellular glutathione, thereby intensifying oxidative stress. Ultimately, this dual activation strategy, combining oxidative and thermal damage, holds significant potential for tumor immunotherapy. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • A fresh type of metal-sensitized sonocatalyst was designed. • The light/sono-responsive nanoplatform can generate adequate ROS and heat. • Generated ROS and heat mutualistically trigger immunogenic cell death. • The sonocatalyst activates immune response, hindering tumor growth and metastasis. Sonodynamic tumor therapy is limited by inefficient sonosensitizers and complex tumor microenvironments. Given this, a concept of metal-sensitized sonocatalyst is proposed and defined as a catalyst based on the metal sensitization effect of noble metals to advance semiconductor sonocatalytic activity. We load Au nanorods onto wide-bandgap semiconductor bismuth oxide to favor its sonocatalytic properties for supporting the concept's practicality. In the catalytic nano-system, Au nanorods improve the ability of bismuth oxide to separate electrons and holes under ultrasound, promoting multifarious reactive oxygen species (ROS) generation and enhancing the photothermal effect. Synergistically, bismuth oxide can consume intratumoral overexpressed glutathione, further disrupting the redox balance. Thus, ROS and heat can directly induce immunogenic cell death, reversing tumor immunosuppressive microenvironment in concert and promoting dendritic cell maturation and CD8+ T cell infiltration. The proposed metal-sensitized sonocatalyst will open up new avenues for sonocatalytic therapy. [ABSTRACT FROM AUTHOR]