Cu- and Fe-Containing Phosphotungstate Nanoparticles with POD-like and GSH-like Activities to Target Inhibition of Gram-Negative Bacteria

At this stage, it is very important to produce strong antibacterial drugs to solve the problem of multidrug resistance caused by overuse of traditional antibiotics because the abuse of antibiotics poses a serious threat to public health. Herein, an effective strategy for targeted killing of Gram-negative bacteria using copper- and iron-containing phosphotungstates (Cu,Fe-PTs) has been reported. Cu,Fe-PTs as a nanozyme can consume glutathione through oxidation, combine with a small amount of H2O2 to produce reactive oxygen species (ROS), and target Gram-negative bacteria. Cu,Fe-PTs could accelerate glutathione (GSH) consumption through the generation of reactive oxygen species (ROS), namely superoxide radical (•O2–) and hydroxyl radical (•OH). It can be proved by the zeta potential and the kinetic parameters that the selective inhibition of Cu,Fe-PTs is due to the good affinity of Cu,Fe-PTs for H2O2 after binding to Gram-negative bacteria, while the stability of the nanozyme is also improved. In addition, Cu,Fe-PTs facilitate electron transfer by providing more active sites through valence transitions between Fe2+/Fe3+ and Cu2+/Cu+. Interestingly, the results of the study showed that Cu,Fe-PTs can be targeted to inhibit Gram-negative bacteria with effective antimicrobial properties against Escherichia coli (E. coli) (∼99.4%) and ampicillin-resistant Escherichia coli (AREC) (∼99.9%). This study provides a strategy for the design of efficient nanozymes and their applications in the field of targeted antimicrobial therapy.