Two-dimensional Ultrathin Iron Doped Bismuth Oxychloride Nanosheets with Rich Oxygen Vacancies for Enhanced Sonodynamic Therapy.

Sonodynamic therapy (SDT) combines ultrasound and sonosensitizers to produce toxic reactive oxygen species (ROS) for cancer cell killing. As the high penetration depth of US, SDT breaks the depth penetration barrier of conventional photodynamic therapy for the treatment of deeply seated tumours. A key point to enhance the therapeutic efficiency of SDT is the development of novel sonosensitizers with promoted ability for ROS production. Herein, ultrathin Fe-doped bismuth oxychloride nanosheets with rich oxygen vacancies and bovine serum albumin coating on surface are designed as piezoelectric sonosensitizers (BOC-Fe NSs) for enhanced SDT. The oxygen vacancies of BOC-Fe NSs provide electron trapping sites to promote the separation of e - -h + from the band structure, which facilitates the ROS production under the ultrasonic waves. The piezoelectric BOC-Fe NSs create a build-in field and the bending bands, further accelerating the ROS generation with ultrasound irradiation. Furthermore, BOC-Fe NSs could induce ROS generation by a Fenton reaction catalysed by Fe ion with endogenous H 2 O 2 in tumour tissues for chemodynamic therapy. The as-prepared BOC-Fe NSs efficiently inhibited breast cancer cell growth in both in vitro and in vivo tests. The successfully development of BOC-Fe NSs provides a new nano-sonosensitiser option for enhanced SDT for cancer therapy. This article is protected by copyright. All rights reserved.