Medium-Dependent Antibacterial Properties and Bacterial Filtration Ability of Reduced Graphene Oxide

Authors

Alexander Gusev, Derzhavin Tambov State UniversityFollow
Olga Zakharova, Derzhavin Tambov State UniversityFollow
Dmitry S. Muratov, National University of Science and Technology “MISIS”Follow
Nataliia S. Vorobeva, University of Nebraska—LincolnFollow
Mamun Sarker, University of Nebraska - LincolnFollow
Iaroslav Rybkin, Saratov State University, SaratovFollow
Daniil Bratashov, Saratov State University, SaratovFollow
Evgeny Kolesnikov, National University of Science and Technology “MISIS”Follow
Aleš Lapanje, Saratov State UniversityFollow
Denis V. Kuznetsov, National University of Science and Technology “MISIS”Follow
Alexander Sinitskii, University of Nebraska-LincolnFollow

Date of this Version

2019

Citation

Nanomaterials 2019, 9, 1454

Comments

© 2019 by the authors. Open access

doi:10.3390/nano9101454

Abstract

Toxicity of reduced graphene oxide (rGO) has been a topic of multiple studies and was shown to depend on a variety of characteristics of rGO and biological objects of interest. In this paper, we demonstrate that when studying the same dispersions of rGO and fluorescent Escherichia coli (E. coli) bacteria, the outcome of nanotoxicity experiments also depends on the type of culture medium. We show that rGO inhibits the growth of bacteria in a nutrition medium but shows little effect on the behavior of E. coli in a physiological saline solution. The observed effects of rGO on E. coli in different media could be at least partially rationalized through the adsorption of bacteria and nutrients on the dispersed rGO sheets, which is likely mediated via hydrogen bonding. We also found that the interaction between rGO and E. coli is medium-dependent, and in physiological saline solutions they form stable flocculate structures that were not observed in nutrition media. Furthermore, the aggregation of rGO and E. coli in saline media was observed regardless of whether the bacteria were alive or dead. Filtration of the aggregate suspensions led to nearly complete removal of bacteria from filtered liquids, which highlights the potential of rGO for the filtration and separation of biological contaminants, regardless of whether they include live or dead microorganisms.