Study of antibacterial mechanism of graphene oxide using Raman spectroscopy.

Sitansu Sekhar Nanda,Dong Kee Yi,Kwangmeyung Kim

doi:10.1038/srep28443

Sitansu Sekhar Nanda, Dong Kee Yi + Show 1 more

Open Access

https://doi.org/10.1038/srep28443

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Abstract

Graphene oxide (GO) is extensively proposed as an effective antibacterial agent in commercial product packaging and for various biomedical applications. However, the antibacterial mode of action of GO is yet hypothetical and unclear. Here we developed a new and sensitive fingerprint approach to study the antibacterial activity of GO and underlying mechanism, using Raman spectroscopy. Spectroscopic signatures obtained from biomolecules such as Adenine and proteins from bacterial cultures with different concentrations of GO, allowed us to probe the antibacterial activity of GO with its mechanism at the molecular level. Escherichia coli (E. coli) and Enterococcus faecalis (E. faecalis) were used as model micro-organisms for all the experiments performed. The observation of higher intensity Raman peaks from Adenine and proteins in GO treated E. coli and E. faecalis; correlated with induced death, confirmed by Scanning electron Microscopy (SEM) and Biological Atomic Force Microscopy (Bio-AFM). Our findings open the way for future investigations of the antibacterial properties of different nanomaterial/GO composites using Raman spectroscopy.

Highlights

The outer membrane of bacteria maintains their morphology and acts as a barrier of protection from external environments
The sharp edges of Graphene oxide (GO) allow it to penetrate through the cell membrane, and the consequential integrity disruption is the major cause of membrane damage[16,17]
In this paper we report on the antibacterial mechanism of GO at the molecular level via Raman spectroscopy at minimum inhibitory concentration (MIC)

Summary

Introduction

The outer membrane of bacteria maintains their morphology and acts as a barrier of protection from external environments. The detection of Raman bands associated with different biomolecules correlated to bacterial cell morphological changes has provided a clear image of the antibacterial effect of GO in cellular cultures of in E coli and E. faecalis at the molecular level.

Results

Conclusion