Initiative ROS generation of Cu-doped ZIF-8 for excellent antibacterial performance

Nowadays, it is urgent to develop initiative antibacterial materials with high efficiency and low toxicity to complement or substitute conventional antibiotics and passive antibacterial materials to eliminate the ever-growing bacterial contamination. Here, a series of Cu-doped ZIF-8 materials are successfully prepared and adopted for disinfection against typical bacteria E. coli and S. aureus in the absence of light. The results show that 7 log (99.99999%) efficiency is achieved at a low dosage of 30 mg mL-1 of 1.35 atomic % Cu doped ZIF-8, orders of magnitude higher than those of Vancomycin, MIL-125-NH2, UiO-66-NH2, Cu-BTC analogs. And this concen-tration is confirmed as low toxicity by the cytotoxicity test. Mechanism investigation shows that reactive oxygen species (ROS) can be generated spontaneously under darkness and low-coordinated copper would contribute to the effective electron transfer for the ROS generation as revealed by the Density Functional Theory calculations. And these ROS would cause oxidative stress and membrane damage to bacterial cells and achieve excellent antibacterial properties. All these results show the potential of Cu-doped ZIF-8 in antibacterial applications, especially in environments without external energy input.

Automated summary

Currently, there is an urgent need to develop highly efficient and low-toxicity active antibacterial materials to complement or replace conventional antibiotics and passive antibacterial materials in order to eliminate the growing bacterial contamination. In this study, a series of Cu-doped ZIF-8 materials were successfully prepared and used for disinfection against E. coli and S. aureus bacteria in the absence of light. The results showed that a low dosage of 30 mg mL-1 of 1.35 atomic % Cu doped ZIF-8 achieved a 7 log (99.99999%) efficiency, which was orders of magnitude higher than other analogs. It was also found to have low toxicity. Mechanism investigation revealed that reactive oxygen species (ROS) could be spontaneously generated under darkness, and low-coordinated copper contributed to effective electron transfer for ROS generation, resulting in oxidative stress and membrane damage to bacterial cells, leading to excellent antibacterial properties. These findings demonstrate the potential of Cu-doped ZIF-8 in antibacterial applications, particularly in environments without external energy input.