Facile synthesis of polydopamine/reduced graphene oxide nanosheets with incorporated copper ions for high antibacterial performance

Abstract

In this work, a facile and green approach for the synthesis of polydopamine/reduced graphene oxide nanosheets with incorporated copper ions (Cu/PDA/RGO) has been reported using bioadhesive PDA. During the process, the coating of PDA occurred through self-assembly and oxidative polymerisation, involving both the reduction of GO nanosheets and immobilisation of Cu ions. The Cu/PDA/RGO nanosheets showed effective and efficient antibacterial performance against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The antibacterial mechanism of the Cu/PDA/RGO nanosheets was also investigated. The death of E. coli cells could be attributed to the disruption of their cell membranes and increased levels of intracellular reactive oxygen species (ROS). However, due to the direct contact between the Cu/PDA/RGO nanosheets and cells, the production of high level ROS ultimately led to the death of S. aureus cells. This research provides a new idea for the synthesis of antibacterial agents.