Construction of an Antibacterial Membrane Based on Dopamine and Polyethylenimine Cross-Linked Graphene Oxide.

Bacterial infections have been considered to be one of the greatest threats to human health. In this study, a covalently cross-linked GO membrane was fabricated through vacuum-assisted filtration self-assembly after being consequentially functionalized with dopamine (GO-PDA) and branched polyethylenimine (GO-PDA-PEI). The characteristics of GO, GO-PDA, and GO-PDA-PEI membranes were confirmed by X-ray diffraction, Fourier transform infrared measurements, scanning electron microscopy images, static water contact angle measurements, etc. The GO-PDA-PEI membrane showed extraordinary stability, compared with GO and GO-PDA, confirmed by ultrasonication treatment. Notably, the GO-PDA-PEI membrane exhibited excellent antibacterial efficiency for both Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli (more than 99%) upon irradiation by a 795 nm near-infrared (NIR) laser. Interestingly, the GO-PDA-PEI membrane can be recycled, that is, the photothermal effect, as well as the 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.