ACS Nano 2015-07-28

Antimicrobial Properties of Graphene Oxide Nanosheets: Why Size Matters.

François Perreault, Andreia Fonseca de Faria, Siamak Nejati, Menachem Elimelech

Index: ACS Nano 9 , 7226-36, (2015)

Full Text: HTML

Abstract

Graphene oxide (GO) is a promising material for the development of antimicrobial surfaces due to its contact-based antimicrobial activity. However, the relationship between GO physicochemical properties and its antimicrobial activity has yet to be elucidated. In this study, we investigated the size-dependency of GO antimicrobial activity using the Gram-negative bacteria Escherichia coli. GO suspensions of average sheet area ranging from 0.01 to 0.65 μm(2) were produced and their antimicrobial activity evaluated in cell suspensions or as a model GO surface coating. The antimicrobial activity of GO surface coatings increased 4-fold when GO sheet area decreased from 0.65 to 0.01 μm(2). The higher antimicrobial effect of smaller GO sheets is attributed to oxidative mechanisms associated with the higher defect density of smaller sheets. In contrast, in suspension assays, GO interacted with bacteria in a cell entrapment mechanism; in this case, the antimicrobial effect of GO increased with increasing sheet area, with apparent complete inactivation observed for the 0.65 μm(2) sheets after a 3 h exposure. However, cell inactivation by GO entrapment was reversible and all initially viable cells could be recovered when separated from GO sheets by sonication. These findings provide useful guidelines for future development of graphene-based antimicrobial surface coatings, where smaller sheet sizes can increase the antimicrobial activity of the material. Our study further emphasizes the importance of an accurate assessment of the antimicrobial effect of nanomaterials when used for antimicrobial surface design.

Related Compounds

Structure Name/CAS No. Articles
Sulfuric acid Structure Sulfuric acid
CAS:7664-93-9
Phosphorus pentoxide Structure Phosphorus pentoxide
CAS:1314-56-3
sodium chloride Structure sodium chloride
CAS:7647-14-5
Ethanol Structure Ethanol
CAS:64-17-5
Hydrogen peroxide Structure Hydrogen peroxide
CAS:7722-84-1
Hydrochloric acid Structure Hydrochloric acid
CAS:7647-01-0
Potassium hydroxide Structure Potassium hydroxide
CAS:1310-58-3
Disodium hydrogenorthophosphate Structure Disodium hydrogenorthophosphate
CAS:7558-79-4
SODIUM CHLORIDE-35 CL Structure SODIUM CHLORIDE-35 CL
CAS:20510-55-8
Monopotassium phosphate Structure Monopotassium phosphate
CAS:7778-77-0