A yolk-shell Pd decorated Au@CeO2 with Schottky junction for long-lived charge separation and bandgap optimization to enhance sonodynamic therapy.

• The ACPP nanoeggs relieve hypoxic tumor microenvironment and elevate the generation of singlet oxygen (1O 2) in SDT. • The ACPP nanoeggs convert H 2 O 2 into hydroxyl radicals (•OH) for chemodynamic therapy (CDT). • The decoration of Pd increased the content ratio of Ce3+/Ce4+, significantly enhanced enzymatic activities of nanoeggs. There is an increasing appreciation for sonodynamic therapy (SDT) that is triggered by ultrasound (US) to treat deep-seated tumors noninvasively. Whereas, the low production of reactive oxygen species (ROS) limits its effect because of the rapid recombination of electron-hole (e–-h+) pairs in sonosensitizers. Herein, Au@CeO 2 -Pd-PFH (ACPP) nanoegg with significantly improved sonosensitization and Fenton-like catalyst was manufactured. Under the irradiation of US, the ACPP nanoegg exhibited improved efficiency of ROS production owing to the narrow bandgap of 1.72 eV and the efficient e–-h+ separation ability. Additionally, the designed ACPP nanoegg mimicked not only peroxidase activity to convert endogenous hydrogen peroxide (H 2 O 2) into hydroxyl radicals (•OH) for chemodynamic therapy (CDT) but also catalase activity to produce oxygen (O 2) for ameliorating hypoxia and enhancing SDT. The decoration of Pd increased the content ratio of Ce3+/Ce4+, significantly elevating the enzymatic activity of nanoegg. With further loading of perfluorohexane (PFH), which led to a transition under US irradiation, US imaging of the tumor was realized. Through both in vitro and in vivo experimental studies, the nanoegg developed in this work was demonstrated to be a promising strategy for cancer nanotheranostic. [ABSTRACT FROM AUTHOR]