scholarly journals Facile preparation of graphene oxide silver aerogel for antibacterial

2021 ◽  
Vol 6 (1) ◽  
pp. 41-44
Author(s):  
An’amt Mohamed Noor ◽  
Nurul Farah Amanina Yusoff ◽  
Huang Nay Ming ◽  
Zulhisyam Abdul Kari ◽  
Mohammad Khairul Azhar Abdul Razab ◽  
...  

We report a simple and straightforward method for the preparation of graphene oxide-silver aerogel (GOAg) via microwave irradiation. Graphene oxide (GO) was used as a substrate for the growth of silver nanoparticles (AgNPs) and silver complex was used as a precursor. The GOAg were prepared by rapidly expose mixture of GO and silver complexes with microwave for 30 s under an ambient atmosphere. For the nanocomposites, GOAg solution were lyophilized in a freeze-dryer for 24 hours to form an aerogel. The obtained GO and GOAg nanocomposites were characterized by X-ray diffractometer (XRD) and Ultraviolet-visible spectroscopy (UV-Vis). XRD confirmed the formation GO, and GOAg while GOAg display antibacterial properties against Methicillin-resistant Staphylococcus aureus (MRSA) and Aeromonas hydrophila bacteria. We demonstrate

2018 ◽  
Vol 32 (19) ◽  
pp. 1840044
Author(s):  
Aditya Dalal ◽  
Animesh Mandal ◽  
Shubhada Adhi ◽  
Kiran Adhi

Aluminum (0.5 at.%)-doped ZnO (AZO) thin films were deposited by pulsed laser deposition technique (PLD) in oxygen ambient of 10[Formula: see text] Torr. The deposited thin films were characterized by x-ray diffraction (XRD), photoluminescence (PL), Raman spectroscopy and uv–visible spectroscopy (UV–vis). Next, graphene oxide (GO) was synthesized by Hummers method and was characterized by XRD, UV–vis spectroscopy, Raman spectroscopy and transmission electron microscopy (TEM). Thereafter, GO solution was drop-casted on AZO thin films. These films were then characterized by Raman Spectroscopy, UV–vis spectroscopy and PL. Attempt is being made to comprehend the modifications in properties brought about by integration.


Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 450 ◽  
Author(s):  
Armin Rajabi ◽  
Mariyam Ghazali ◽  
Ebrahim Mahmoudi ◽  
Amir Baghdadi ◽  
Abdul Mohammad ◽  
...  

In this study, Ag2O was synthesized on polyethylene terephthalate fabrics by using an ultrasonic technique with Ag ion reduction in an aqueous solution. The effects of pH on the microstructure and antibacterial properties of the fabrics were evaluated. X-ray diffraction confirmed the presence of Ag2O on the fabrics. The fabrics were characterized by Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, and wettability testing. Field-emission scanning electron microscopy verified that the change of pH altered the microstructure of the materials. Moreover, the antibacterial activity of the fabrics against Escherichia coli was related to the morphology of Ag2O particles. Thus, the surface structure of Ag2O particles may be a key factor of the antibacterial activity.


Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1043 ◽  
Author(s):  
Honghai Li ◽  
Yu Chen ◽  
Weipeng Lu ◽  
Yisheng Xu ◽  
Yanchuan Guo ◽  
...  

Current wound dressings have poor antimicrobial activities and are difficult to degrade. Therefore, biodegradable and antibacterial dressings are urgently needed. In this article, we used the hydrothermal method and side-by-side electrospinning technology to prepare a gelatin mat with incorporated zinc oxide/graphene oxide (ZnO/GO) nanocomposites. The resultant fibers were characterized by field emission environment scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffractometry (XRD) and Fourier transform infrared spectroscopy (FTIR). Results indicated that the gelatin fibers had good morphology, and ZnO/GO nanocomposites were uniformly dispersed on the fibers. The loss of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) viability were observed to more than 90% with the incorporation of ZnO/GO. The degradation process showed that the composite fibers completely degraded within 7 days and had good controllable degradation characteristics. This study demonstrated the potential applicability of ZnO/GO-gelatin mats with excellent antibacterial properties as wound dressing material.


Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3360
Author(s):  
Jianming Liao ◽  
Shuaiming He ◽  
Shasha Guo ◽  
Pengcheng Luan ◽  
Lihuan Mo ◽  
...  

Graphene-based nanocomposites have attracted tremendous attention in recent years. In this study, a facile yet effective approach was developed to synthesize reduced graphene oxide and an Ag–graphene nanocomposite. The basic strategy involved in the preparation of reduced graphene oxide includes reducing graphene oxide with dopamine, followed by in situ syntheses of the Ag-PDA-reducing graphene oxide (RGO) nanocomposite through adding AgNO3 solution and a small amount of dopamine. The nanocomposite was characterized by transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray diffraction (XRD), FTIR spectra, Raman spectra, ultraviolet-visible (UV-vis), and X-ray photoelectron spectroscopy (XPS), results indicated that a uniform PDA film is formed on the surface of the GO and GO is successfully reduced. Besides, the in situ synthesized Ag nanoparticles (AgNPs) were evenly distributed on the RGO surface. To investigate antibacterial properties Ag-PDA-RGO, different dosages were selected for evaluating the antibacterial activity against Gram-positive bacteria Staphylococcus aureus and Gram-negative bacteria Escherichia coli. The Ag-PDA-RGO nanocomposites displayed excellent antibacterial property. The antibacterial ratio reached 99.9% against S. aureus and 90.9% against E. coli when the dosage of 100 mg/L Ag-PDA-RGO nanocomposites was 100 μL. The novel Ag-PDA-RGO nanocomposite prepared by a facile yet effective, environmentally friendly, and low-cost method holds great promise in a wide range of modern biomedical applications.


2020 ◽  
Vol 981 ◽  
pp. 23-28
Author(s):  
Wan Sin Lim ◽  
Kwok Feng Chong

Graphene oxide (GO) is a promising material that currently a common precursor in the synthesis of graphene material. GO has emerged as a rapidly developed material due to its remarkable application in electronics, energy storage, biomedical and chemistry. However, controlling the oxygen content in the GO is one of the significant factors for tailoring GO that able to fulfil various applications. In this paper, diluted sulfuric acid was employed during the oxidation. Based on the characterization results from Fourier Transform Infrared Spectrometer (FTIR), Ultraviolet-visible spectroscopy (UV-Vis), X-ray diffraction (XRD) and Thermogravimetric analysis (TGA) it found that the partially oxidized graphene oxide (PGO) was fabricated. The PGO synthesis show an insignificant absorption of C=O peak in FTIR and weak peak intensity at 300 nm for UV-Vis analysis that found in fully oxidized graphene oxide. Therefore, the PGO synthesis claimed to be partially oxidized.


2020 ◽  
Vol 1010 ◽  
pp. 590-595
Author(s):  
Farah Amanina Mohd Zin ◽  
An'amt Mohamed Noor ◽  
Seong Wei Lee ◽  
Mohd Shaiful Sajab ◽  
Mohammad Khairul Azhar Abdul Razab ◽  
...  

A novel approach for the synthesis of graphene oxide silver alginate has been developed for the antibacterial performance. Graphene oxide (GO) was used as a supporting material towards formation of silver nanoparticle (AgNPs) by a rapid microwave irradiation on mixture of GO and silver complexes and layered on alginate film. The obtained nanocomposite were characterized by using Ultraviolet-visible spectroscopy (UV-Vis), Xray diffraction (XRD) to confirm the formation of GOAgAlginate. The surface morphological studies for the nanocomposite was done by using scanning electron microscope (SEM). Nanometer-sized AgNPs (an average diameter of about 70 nm) with spherical-shape structure loaded on the GO Alginate layer showed a good antibacterial towards E.Coli and Methicillin-resistant Staphylococcus aureus (MRSA).


Author(s):  
R. Preethi ◽  
P. Padma

The study focused on the green synthesis of silver nanobioconjugates (AgNPs) from phenolic-rich fruit source, Vitis vinifera seed extract and its major component phenolic, resveratrol respectively. Sunlight exposure for 20 minutes was the method of choice for the synthesis of AgNPs of the extract as well as the phenolic, resveratrol. The synthesized nanobioconjugates were characterized using UV-Visible spectroscopy, Transmission electron microscopy (TEM), Energy dispersive X-ray analysis (EDAX), X-ray diffraction (XRD), Polydispersity index, Zeta potential and Fourier transform infrared spectroscopy (FTIR). The reduction of silver ions was confirmed by UV-visible spectroscopy with peaks at 440nm for both nanobioconjugates synthesized from seed extract and compound. The nanobioconjugates showed the spherical in shape with 14-35nm in size and crystalline in nature. The conjugates are well dispersed with 0.301 and 0.287 polydispersity index and the zeta potential range at -13.6 and -14.3mV for stability. The FTRI data proved that the components in grape seeds act as good reductants and stabilizers for the silver nanobioconjugate synthesis. All the synthesized nanobioconjugates exhibited steady and sustained release of the medicinal components conjugated, proving their druggability, and were biocompatible with human cells, demonstrating their safety. The findings of the study validate the anticancer properties of silver nanobioconjugates of Vitis vinifera and its active component resveratrol.


Author(s):  
Guru Kumar Dugganaboyana ◽  
Chethankumar Mukunda ◽  
Suresh Darshini Inakanally

In recent years, green nanotechnology-based approaches using plant materials have been accepted as an environmentally friendly and cost-effective approach with various biomedical applications. In the current study, AgNPs were synthesized using the seed extract of the Eugenia uniflora L. (E.uniflora). Characterization was done using UV-Visible spectroscopy, X-ray diffraction (XRD), scanning electronic microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) analyses. The formation of AgNPs has confirmed through UV-Visible spectroscopy (at 466 nm) by the change of color owing to surface Plasmon resonance. Based on the XRD pattern, the crystalline property of AgNPs was established. The functional group existing in seed of E.uniflora extract accountable for the reduction of Ag+ ion and the stabilization of AgNPs was investigated. The morphological structures and elemental composition was determined by SEM and EDX analysis. With the growing application of AgNPs in biomedical perspectives, the biosynthesized AgNPs were evaluated for their antibacterial and along with their antidiabetic potential. The results showed that AgNPs are extremely effective with potent antidiabetic potential at a very low concentration. It also exhibited potential antibacterial activity against the three tested human pathogenic bacteria. Overall, the results highlight the effectiveness and potential applications of AgNPs in biomedical fields such as in the treatment of acute illnesses as well as in drug formulation for treating various diseases such as cancer and diabetes. It could be concluded that E. uniflora seed extract AgNPs can be used efficiently for in vitro evaluation of their antibacterial and antidiabetic effects with potent biomedical applications.


Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1023 ◽  
Author(s):  
Ashish Chhaganlal Gandhi ◽  
Chia-Liang Cheng ◽  
Sheng Yun Wu

We report the synthesis of room temperature (RT) stabilized γ–Bi2O3 nanoparticles (NPs) at the expense of metallic Bi NPs through annealing in an ambient atmosphere. RT stability of the metastable γ–Bi2O3 NPs is confirmed using synchrotron radiation powder X-ray diffraction and Raman spectroscopy. γ–Bi2O3 NPs exhibited a strong red-band emission peaking at ~701 nm, covering 81% integrated intensity of photoluminescence spectra. Our findings suggest that the RT stabilization and enhanced red-band emission of γ‒Bi2O3 is mediated by excess oxygen ion vacancies generated at the octahedral O(2) sites during the annealing process.


Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 89
Author(s):  
Wei Yuan ◽  
Qian Hu ◽  
Jiao Zhang ◽  
Feng Huang ◽  
Jing Liu

This study modified graphene oxide (GO) with hydrophilic octadecylamine (ODA) via covalent bonding to improve its dispersion in silicone-modified epoxy resin (SMER) coatings. The structural and physical properties of ODA-GO were characterized by field-emission scanning electron microscopy (FE-SEM), X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and contact angle tests. The ODA-GO composite materials were added to SMER coatings by physical mixing. FE-SEM, water absorption, and contact angle tests were used to evaluate the physical properties of the ODA-GO/SMER coatings, while salt spray, electrochemical impedance spectroscopy (EIS), and scanning Kelvin probe (SKP) methods were used to test the anticorrosive performance of ODA-GO/SMER composite coatings on Q235 steel substrates. It was found that ODA was successfully grafted onto the surfaces of GO. The resulting ODA-GO material exhibited good hydrophobicity and dispersion in SMER coatings. The anticorrosive properties of the ODA-GO/SMER coatings were significantly improved due to the increased interfacial adhesion between the nanosheets and SMER, lengthening of the corrosive solution diffusion path, and increased cathodic peeling resistance. The 1 wt.% ODA-GO/SMER coating provided the best corrosion resistance than SMER coatings with other amounts of ODA-GO (including no addition). After immersion in 3.5 wt.% NaCl solution for 28 days, the low-frequency end impedance value of the 1 wt.% ODA-GO/SMER coating remained high, at 6.2 × 108 Ω·cm2.


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