Antibacterial activities and mechanisms of fluorinated graphene and guanidine-modified graphene

RSC Advances ◽  
2016 ◽  
Vol 6 (11) ◽  
pp. 8763-8772 ◽  
Author(s):  
Xu Wang ◽  
Peng Lu ◽  
Yuan Li ◽  
Huining Xiao ◽  
Xiangyang Liu

The antibacterial properties and mechanism of three types of graphene derivatives, graphene oxide (GO), fluorinated graphene (FG), and guanidine-modified graphene (PHGH-G), were comparatively studied.

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
R. Mahendran ◽  
D. Sridharan ◽  
K. Santhakumar ◽  
T. A. Selvakumar ◽  
P. Rajasekar ◽  
...  

The incorporation of carbonaceous nanofillers into polymers can result in significant materials with improved physicochemical properties and novel composite functionalities. In this study, we have fabricated antibacterial, lightweight, transparent, and flexible graphene oxide (GO) reinforced polycarbonate thin films by a facile and low-cost methodology. Solution blending is employed to get a homogeneous mixture of PC-GO composites at various loading of GO, and the thin films are prepared by dry-wet phase inversion technique. Thermal studies and micrographs of the films revealed the incorporation of GO in PC matrix. Microstructure of the thin films showed the homogeneous dispersion of GO at micro- and nanoscales; however, at higher loading of GO (0.7%), significant agglomeration is observed. More importantly, PC-GO composite films exhibited excellent antibacterial activities against E. coli and S. aureus, owing to the antibacterial nature of GO nanoparticles.


Author(s):  
Imad H. Khaleel ◽  
Abdulkareem A. Alkhafaji ◽  
Hussein A. Miran ◽  
Zainab N. Jaf

In this research, a novel thin film Si-GO10 and nano-powders Si-GO30 of silica-graphene oxide composite were prepared via sol-gel method and deposited on glass substrates using spray pyrolysis. XRD results showed a relatively strong peak in graphite layer that corresponds to the plane of (002). TEM images displayed that SiO<sub>2</sub> nano-particles were randomly distributed on the surface of Si-GO30 sample, and the particle size in these nano-powders was below 50 nm. Moreover, silica nano-particles on the surface of GO plates exhibited almost a spherical and rod-like nanoparticles shapes, which in turn confirmed the formation of SiO<sub>2</sub>-GO nano-hybrids. FESEM analysis reveals a different morphology, the Si-GO10 sample is so rough and crumble, while the Si-GO30 sample is relatively smooth on the surface. Photocatalytic investigations revealed the composite materials exhibit high activity for dye adsorption and decomposition. Si-GO10 thin film did not undergo degradation after 120 minutes, however, for Si-GO30 nano-powder, the adsorption peak intensity was reduced to 665 nm, indicating a decrease in the dye concentration in the solution. FTIR analysis demonstrated that carboxylic functional groups are decreased by increasing silica particles. Photo-Luminescence (PL) spectrum in Si-GO10 thin film disclosed a severe emission peak at about 675 nm. This spectrum was completely disappeared in Si-GO30 nano-powders. Results of the antibacterial properties emphasized that Si-GO30 nano-particle would prevent Escherichia. coli growth after 20 hours. The presented methodology allows for the synthesis of graphene oxide supported silicon dioxide nano-particles for promising applications in photocatalytic and antibacterial fields.


2018 ◽  
Vol 792 ◽  
pp. 89-97
Author(s):  
Xiao Feng Zhao ◽  
Zi Li Yu ◽  
Cong Li Fu ◽  
Xiu Li Wang

For many excellent graphene derivatives, tailoring the material properties is crucial to get a broader application. In the present work, a series of fluorinated graphene oxide (FGO) with various oxidation degree were synthesized using a modified Hummers method at different reaction temperatures. The structure and property of FGO were analyzed by X-ray diffraction (XRD), Fourier transform infra-red spectra (FT-IR), X-ray photoelectron spectra (XPS) and Zeta potential analysis. The results indicate that the oxygen contents range from 5.61 % to 21.96 % in FGO can be tuned by altering the reaction temperatures. The oxygen in FGO is presented mainly in the form of epoxide and carboxyl groups. With increasing reaction temperature from 50 °C to 90 °C, the oxygen content in FGO decreases and thicker multilayered FGO is formed with lower dispersibility.


2011 ◽  
Vol 21 (10) ◽  
pp. 3350-3352 ◽  
Author(s):  
Jizhen Ma ◽  
Jintao Zhang ◽  
Zhigang Xiong ◽  
Yu Yong ◽  
X. S. Zhao

RSC Advances ◽  
2015 ◽  
Vol 5 (100) ◽  
pp. 81994-82004 ◽  
Author(s):  
Shikha Singh ◽  
Ravi Kumar Gundampati ◽  
Kheyanath Mitra ◽  
K. Ramesh ◽  
Medicherla V. Jagannadham ◽  
...  

PNVP grafted on GO regulates the size of Ag nanoparticles and enhances the catalytic and antibacterial properties along with increase in the dispersibility of GO.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Lei Huang ◽  
Hongtao Yang ◽  
Yanhua Zhang ◽  
Wei Xiao

Using graphene oxide as substrate and stabilizer for the silver nanoparticles, silver nanoparticles-graphene oxide (Ag NPs/GO) composites with different Ag loading were synthesized through a facile solution-phase method. During the synthesis process, AgNO3on GO matrix was directly reduced by NaBH4. The structure characterization was studied through X-ray diffraction (XRD), atomic force microscopy (AFM), high-resolution transmission electron microscope (HRTEM), ultraviolet-visible spectroscopy (UV-Vis), and selected area electron diffraction (SAED). The results show that Ag nanoparticles (Ag NPs) with the sizes ranging from 5 to 20 nm are highly dispersed on the surfaces of GO sheets. The shape and size of the Ag NPs are decided by the volume of initial AgNO3solution added in the GO. The antibacterial activities of Ag NPs/GO nanocomposites were investigated and the result shows that all the produced composites exhibit good antibacterial activities against Gram-negative (G−) bacterial strainEscherichia coli(E. coli) and Gram-positive (G+) strainStaphylococcus aureus(S. aureus). Moreover, the antibacterial activities of Ag NPs/GO nanocomposites gradually increased with the increasing of volume of initial AgNO3solution added in the GO and this improvement of the antibacterial activities results from the combined action of size effect and concentration effect of Ag NPs in Ag NPs/GO nanocomposites.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Lin Zhao ◽  
Guangxin Duan ◽  
Zaixing Yang ◽  
Jeffrey K. Weber ◽  
Xu Liu ◽  
...  

Recent studies have indicated that graphene and its derivative graphene oxide (GO) engage in a wide range of antibacterial activities with limited toxicity to human cells. Here, we systematically evaluate the dependence of GO toxicity on the size of the nanoparticles used in treatments: we compare the cytotoxic effects of graphene quantum dots (GQDs, <15 nm), small GOs (SGOs, 50–200 nm), and large GOs (LGOs, 0.5–3 μm). We synthesize the results of bacterial colony count assays and SEM-based observations of morphological changes to assess the antibacterial properties that these GOs bring into effect againstE. coli. We also use Live/Dead assays and morphological analysis to investigate changes to mammalian (Murine macrophage-like Raw 264.7) cells induced by the presence of the various GO particle types. Our results demonstrate that LGOs, SGOs, and GQDs possess antibacterial activities and cause mammalian cell cytotoxicity at descending levels of potency. Placing our observations in the context of previous simulation results, we suggest that both the lateral size and surface area of GO particles contribute to cytotoxic effects. We hope that the size dependence elucidated here provides a useful schematic for tuning GO-cell interactions in biomedical applications.


Nanoscale ◽  
2014 ◽  
Vol 6 (17) ◽  
pp. 10140-10146 ◽  
Author(s):  
Sidhureddy Boopathi ◽  
Tharangattu N. Narayanan ◽  
Shanmugam Senthil Kumar

Augmented electron transfer kinetics of fluorinated graphene oxide (FGO) in comparison to graphene oxide is demonstrated. FGO and reduced FGO perform enhanced electro-catalytic activities, where the fluorine atom can modify the electronic as well as electrochemical activities of graphene surface.


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