Construction Of Graphene Oxide-based Composite Membrane Materials And Visualization Nanoplatform For Phototherapy Antibacterial Application

Antibiotics are the fast and effective antibacterial agents,but drug resistance caused by abuse of antibiotics is a serious problem in the medical field.To overcome this problem,several non-traditional antibacterial agents have been studied,such as carbon nanotubes,metal nanoparticles and metal oxide nanoparticles.Compared with these antibacterial agents,graphene and its derivatives have higher bacterial toxicity,negligible mammalian cytotoxicity,and unique physical and chemical properties.Due to the limitations of the existing antibacterial methods,there is an urgent need for a reliable antibacterial method that has universality,small side effects,being able to treated locally and repeatedly,and coordinate with other methods.Photothermal antibacterial is a minimally invasive,controllable and efficient antibacterial method that has been widely concerned.Graphene oxide(GO)has been widely used in antibacterial research due to its excellent light-to-heat conversion efficiency and structural specificity.Photodynamic antibacterial is a method in which a photosensitizer is irradiated by a light source to produce cytotoxic reactive oxygen species(ROS)and irreversibly kills bacteria.However,most photosensitizers are affected by the decrease in efficacy caused by aggregation,and therefore it is necessary to develop new photosensitizers having the ability to significantly produce ROS in the aggregated state.Here,we constructed a covalently cross-linked composite antibacterial membrane(GO-PDA-PEI)through vacuum-assisted filtration self-assembly method.Due to the covalent cross-linking of GO-PDA catechol groups and the amine groups of PEI,GO-PDA-PEI membrane showed prominent stability in aqueous solutions.Under the irradiation of 795 nm near-infrared(NIR)laser,its antibacterial efficiency against S.aureus and E.coli reached 99%.Moreover,the photothermal effect and antibacterial activity of the GO-PDA-PEI membrane,remained the same after 5-time recycling.Hence,the proposed system has great potential for future design of recyclable,highly stable,superior bacteriostatic membrane materials.On the other hand,to overcome the multi-drug resistance of bacteria,antibacterial materials need high-efficiency,controllable antibacterial effect and good biocompatibility.Herein,nano graphene oxide(NGO)-based NIR photothermal antibacterial materials was schemed to complex with biocompatible bovine serum albumin(BSA)and aggregation?induced emission fuorogen(AIEgen)by nanoprecipitation method for dual-mode phototherapy antibacterial.Compared with solo phototherapy,under the co-irradiation of daylight and NIR laser,NGO-BSA-AIE nanoparticles had superiorly antibacterial efficiency against AMO~r S.aureus and AMO~r E.coli(more than 99%).Meanwhile,the NGO-BSA-AIE nanoparticles displayed prominent stability and biocompatibility.More importantly,under daylight irradiation,the AIEgen can present fuorescence image for tracking bacteria.Therefore,the designed system provided an important platform for photothermal/photodynamic antibacterial under the guidance of bio-imaging.