ZnO quantum dots decorated BaTiO₃ for cancer sonodynamic therapy

Sonodynamic therapy depending on ultrasound irradiation, which generates reactive species to kill cancer cells, has attracted considerable attention due to the deep tissue penetration depth. However, the insufficient separation of electron/hole pairs induces its limited therapeutic efficiency. Herein, we use oxygen vacancy and ZnO quantum dots decoration techniques to enhance electron/hole separation and reactive species production. In oxygen vacancy-engineered BaTiO₃, the higher oxygen vacancy concentration leads to more efficient adsorption of activate O₂ and thus results in production of more radicals. In BaTiO₃/ZnO heterostructures, the built-in electric field further improves separation of electron/hole pairs. The separated electron/hole react with O₂/H₂O to produce reactive species of •OH/∙O₂^- and kill cancer cells upon ultrasound irradiation. The work provides a guidance for sonosensitizers to tumor therapy.