Neodymium Single‐Atom Regulator via Electronic State Nonlinear Change for Piezoelectric Sonodynamic Therapy

ABSTRACT In recent years, using ultrasound‐sensitive characteristics of piezoelectric materials for antitumor therapy has become a rapidly developing therapeutic method. However, the limited piezoelectric catalytic efficiency severely constrains the efficacy of piezoelectric sonodynamic therapy (SDT). It is still urgent to propose effective strategies to improve the efficiency of piezoelectric catalysis. In this study, we construct a neodymium (Nd) single‐atoms electronic regulator by loading Nd single‐atoms on vacancy‐enriched Bi 2 O 3 support (Nd SABs). The introduction of Nd single‐atoms provides electrons that modulate electron transfer and enhance the activation of adsorbed oxygen, promoting the production of toxic reactive oxygen species (ROS) under ultrasound (US) irradiation to inhibit tumor cells. Both in vitro and in vivo experiments show that Nd SABs efficiently generate ROS and exhibit excellent antitumor effects under US irradiation. In addition, Nd single‐atoms on Nd SABs can emit the desired second near‐infrared window (NIR‐II) emission under 808 nm laser irradiation to achieve NIR‐II fluorescence imaging. This work not only proposes a strategy of using rare earth single‐atom electronic regulators to improve piezoelectric catalytic efficiency, but also reports NIR‐II emission of Nd single‐atoms, which expands the application of rare earth single‐atoms systems in the field of tumor diagnosis and therapy.