Cu–Ce oxide Co-loaded silicon nanocapsules for hydrogen peroxide self-supplied Fenton-like catalysis and synergistically antibacterial therapy

Antibacterial strategies based on reactive oxygen species (ROS) have opened up a new avenue for overcoming the great challenges of antibiotics topic including lack of broad-spectrum antibiotics and the emergence of super-resistant bacteria. Herein, we leveraged a strategy of constructing synergistic catalytic active sites to develop a simple yet efficient Fenton-like active nanocomposite, and investigated its catalysis mechanism and antibacterial performance thoroughly. This strategy provides a new direction for boosting the catalytic activity of nanocomposite catalysts for wide application. Specifically, by uniformly loading copper oxide and ceria onto the surface of silica nanocapsules (SiO 2 NCs), we fabricated a bimetallic oxide nanocomposite Cu 0.75 Ce 0.62 O 2 @SiO 2 NC, which performed superior Fenton-like capability in a wide pH range without additional exogenetic hydrogen peroxide (H 2 O 2 ). Such excellent catalytic activity was originated from the charge interaction between the two metal oxide components, where formation of Cu + and oxygen vacancies (OVs) was mutually reinforcing, resulting in a synergistic effect to produce H 2 O 2 and catalyze the generation of •OH under the slight acid condition (pH = 6.0). In view of the outstanding Fenton-like activity, the Cu 0.75 Ce 0.62 O 2 @SiO 2 NC was employed in antimicrobial testing, which demonstrated exceptional high in vitro antimicrobial efficacy against both the S. aureus and E. coli in a neutral environment (pH = 7.4). The excellent performance of the bimetallic nanocomposite Cu 0.75 Ce 0.62 O 2 @SiO 2 NC, including its facile and mild preparation, high water-solubility and stability, superior catalytic and antimicrobial performances, manifests a promising broad-spectrum antibiotic that can be anticipated to deal with the contamination of the environment by bacteria.