Defect engineering in cobalt-doped prussian blue to enhance sonocatalytic activities for anticancer treatment

The effect of sonocatalysis on anticancer treatment is always restricted by rapid recombination of charge and low utilization of the ultrasonic cavitation effect. Herein, cobalt-doped prussian blue (PB) nanocubes were synthesized, and then they were etched by acidic solution to obtain amorphous Co-FePB@1h with abundant defects including: Fe/Co defects, Fe-(CN)₆ vacancies, and dangling bonds. Both doping and defect engineering contribute to decreasing the band gap and promoting charge separation. Additionally, these strategies can regulate the band level to increase the potential of the conduction band (CB), promoting the thermodynamic feasibility and production (6-times) of reactive oxygen species (ROS). Simultaneously, US-generated holes can also oxidize endogenous glucose and nicotinamide adenine dinucleotide phosphate (NADPH), which not only further inhibit electron-hole recombination but can also depress energy supply and reductive stress, facilitating anticancer treatment. Moreover, the defect engineering can not only bring extra porous structure to enhance the ultrasonic cavitation effect but can also increase active sites to improve peroxidase (POD) activity for chemodynamic therapy (CDT). The intracellular sonocatalysis associated with nanozyme activity exhibits a notable anticancer effect. These treatments can promote immungenic cell death (ICD), thereby stimulating anticancer immune activation to combat metastasis and recurrence. With the various constituents/structures and regulatable defects, PB nanomaterials possess great potential as sonosensitizers directly for achieving great performance in sonocatalysis.