Adhesion of Bacteria to a Graphene Oxide Film.

Graphene oxide (GO)-based materials have recently received increasing attention in antibacterial fields due to their unique two-dimensional structure, high specific surface area, water solubility, easy functionality, low cost, etc. In this work, we investigated the interaction of GO films with several bacteria, including Escherichia coli, Staphylococcus aureus, Bacillus, and Shewanella-MR 1. Surprisingly, it was found that GO films had no influence on the growth of bacteria; bacteria could selectively attach on the GO films, and the adhesion efficiency was dependent on the genus of bacteria and the quality of GO films, as confirmed by quartz crystal microbalance (QCM) measurement. X-ray photoelectron spectroscopy, Ramam spectra analyses, and current-voltage curves further indicated that the bacteria could reduce GO to reductive GO (rGO) or graphite. Through constant current measurements, a possible mechanism that involved electron transfer from bacteria to the GO film was proposed for the adherence of bacteria to GO films and reduction of GO films by bacteria. The study suggested that GO films could act as biocompatible sites for adhesion of bacteria on their surfaces, providing a paradigm for exploring the interaction of GO-related materials with bacteria.