Oxidative stress-mediated antibacterial activity of graphene oxide and reduced graphene oxide in Pseudomonas aeruginosa

Abstract

Background: Graphene holds great promise for potential use in next-generation electronic and photonic devices due to its unique high carrier mobility, good optical transparency, large surface area, and biocompatibility. The aim of this study was to investigate the antibacterial effects of graphene oxide (GO) and reduced graphene oxide (rGO) in Pseudomonas aeruginosa. In this work, we used a novel reducing agent, betamercaptoethanol (BME), for synthesis of graphene to avoid the use of toxic materials. To uncover the impacts of GO and rGO on human health, the antibacterial activity of two types of graphene-based material toward a bacterial model P. aeruginosa was studied and compared. Methods: The synthesized GO and rGO was characterized by ultraviolet-visible absorption spectroscopy, particle-size analyzer, X-ray diffraction, scanning electron microscopy and Raman spectroscopy. Further, to explain the antimicrobial activity of graphene oxide and reduced graphene oxide, we employed various assays, such as cell growth, cell viability, reactive oxygen species generation, and DNA fragmentation. Results: Ultraviolet-visible spectra of the samples confirmed the transition of GO into graphene. Dynamic light-scattering analyses showed the average size among the two types of graphene materials. X-ray diffraction data validated the structure of graphene sheets, and high-resolution scanning electron microscopy was employed to investigate the morphologies of prepared graphene. Raman spectroscopy data indicated the removal of oxygen-containing functional groups from the surface of GO and the formation of graphene. The exposure of cells to GO and rGO induced the production of superoxide radical anion and loss of cell viability. Results suggest that the antibacterial activities are contributed to by loss of cell viability, induced oxidative stress, and DNA fragmentation. Conclusion:The antibacterial activities of GO and rGO against P. aeruginosa were compared. The loss of P. aeruginosa viability increased in a dose-and time-dependent manner. Exposure to GO and rGO induced significant production of superoxide radical anion compared to control. GO and rGO showed dose-dependent antibacterial activity against P. aeruginosa cells through the generation of reactive oxygen species, leading to cell death, which was further confirmed through resulting nuclear fragmentation. The data presented here are novel in that they prove that GO and rGO are effective bactericidal agents against P. aeruginosa, which would be used as a future antibacterial agent.

Graphene Oxide as Antimicrobial Against Two Gram-Positive and Two Gram-Negative Bacteria in Addition to One Fungus

“…The observed interlayer spacing of S-3 was 3.7018 A° (0.37 nm), due to the presence of oxygenated functional groups and intercalated water molecules which corresponds to the GO. The XRD results of GO samples are in good agreement with the literature (Kaniyoor et al, 2010;Du et al, 2010;Gurunathan et al, 2012).…”

Osteogenesis and Antibacterial Activity of Graphene Oxide and Dexamethasone Coatings on Porous Polyetheretherketone via Polydopamine-Assisted Chemistry

“…In fact, keen-edged marginal parts of GO impose membrane stress on bacteria which contributes to cell destruction. Besides, GO produces oxidative stress that originates from reactive oxygen species (ROS) which harm bacterial DNA and structure, and are key to its anti-bacterial activity [49].…”

Fabrication and Characterization of Electrospun PHA/Graphene Silver Nano-Composite Scaffold for Antibacterial Application

“…As evident from figure 6a, the UV-vis spectrum of Ag-NPs exhibit a distinct broad absorption peak at about 410 nm which is the characteristic peak for Ag and indicates the successful formation of Ag-NPs [50]. On the other hand, the UV-vis spectrum of rGO (Figure 6b) demonstrates a broad band at 260 nm which can be attributed to the conjugated sp 2 carbon network in rGO and is a characteristic of rGO [51]. Since, no significance plasmon peak appears at 300 nm in the spectrum of rGO, suggesting the removal of oxygen groups and thereby confirming the successful reduction of GO to rGO [52].…”