Graphene Oxide Silver Cellulose Alginate for Antibacterial

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 ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Spherical Shape ◽  
Average Diameter ◽  
Silver Complexes ◽  
Visible Spectroscopy ◽  
Antibacterial Performance ◽  
Morphological Studies ◽  
Novel Approach ◽  
Shape Structure ◽  
Supporting Material

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).

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 ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Aeromonas Hydrophila ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Antibacterial Properties ◽  
Ambient Atmosphere ◽  
Silver Complexes ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Straightforward Method ◽  
Freeze Dryer

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

Graphene Oxide as a Substrate for Biosensors: Synthesis and Characterization

2021 ◽  
Vol 324 ◽  
pp. 87-93
Author(s):  
Mohamed Adel ◽  
Abdel Hady A. Abdel-Wahab ◽  
Ahmed Abdel-Mawgood ◽  
Ahmed Osman Egiza
Keyword(s):  
Raman Spectroscopy ◽  
Graphene Oxide ◽  
Acidic Solution ◽  
Cost Effective ◽  
Sem Analysis ◽  
Visible Spectroscopy ◽  
Sem Images ◽  
Hummers Method ◽  
Uv Visible ◽  
Modified Hummers Method

Graphene oxide (GO) is an oxidized nanosheets of graphite with a 2D planar structure. GO could be readily complexed with bio-entities as it possesses many oxygen-containing functionalities on its surface. The preparation process is fast, easy, and cost-effective. It was prepared using modified Hummers’ method in acidic solution as a primary solvent and potassium permanganate as an oxidizing agent. Afterwards, it was successfully characterized by FTIR, UV-visible spectroscopy, as well as XRD and Raman spectroscopy, and finally, SEM analysis. It was observed that the formed GO is mainly composed of carbon and oxygen elements rich in oxygen functional groups. Furthermore, the existence of (001) plane in XRD interprets the complete oxidation of graphite with d-spacing 9 Å. Moreover, Raman spectroscopy displayed the sp3 carbon hybridization, besides, the ID/IG ratio is found to be 0.84, which confirms the disorder between graphene oxide layers. The SEM images also pointed out that graphene oxide sheets were regularly stacked together as flake-like structures. Accordingly, the richness of oxygen-containing functionalities was confirmed. Hence, it is appropriate to be used as a base transducer for biosensing applications.

Effect of Gold Nanoparticles Size on Detection of Methylphosphonic Acid Hydrolysis Product of Nerve Agent

2021 ◽  
Vol 25 (7) ◽  
pp. 1-7
Author(s):  
Fellyzra Elvya Pojol ◽  
Buong Woei Chieng ◽  
Keat Khim Ong ◽  
Rashid Jahwarhar Izuan Abd ◽  
Mohd Junaedy Osman ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Inverse Method ◽  
Direct Method ◽  
Hydrolysis Product ◽  
Spherical Shape ◽  
Methylphosphonic Acid ◽  
Visible Spectroscopy ◽  
Transmission Electron ◽  
Citrate Reduction ◽  
Chloride Trihydrate

Citrate reduction of gold (III) chloride trihydrate (HAuCl4) is commonly used method to synthesise citrate-capped gold nanoparticles (cit-AuNPs). In this study, the sequence of reagents addition was modified (“inverse” method) to synthesise smaller size of cit-AuNPs than the standard Turkevich method (“direct” method). Ultraviolet-visible spectroscopy (UV-vis) and field emission transmission electron microscopy (FETEM) confirmed the formation of cit-AuNPs. The cit-AuNPs synthesized using “inverse” method are smaller in size (14.0 ± 3.03 nm) with uniform spherical shape compared to “direct” method (23.5 ± 7.52 nm). Smaller particles size of cit-AuNPs provide higher efficiency and sensitivity for detection of methylphosphonic acid (MPA) via colorimetric incorporated with image processing with a linear range from 2.5 to 12.5 mM and a low detection limit of 6.28 mM at shorter detection period (24 to 30 s).

A Novel Approach to Nanoscale Materials Synthesis Using Industrial Laser Processing of Organosilazane Liquid Precursors

1990 ◽  
Vol 206 ◽  
Author(s):  
Tongsan D. Xiao ◽  
Peter R. Strutt ◽  
Kenneth E. Gonsalves
Keyword(s):  
Ceramic Powder ◽  
Average Diameter ◽  
Current Approach ◽  
Powder Materials ◽  
Materials Synthesis ◽  
Laser Plume ◽  
New Approach ◽  
Novel Approach ◽  
Liquid Precursors ◽  
Short Time

ABSTRACTA new approach has been developed for the synthesis of nanoscale ceramic powder materials from liquid organosilazane precursors. This technique, by exploiting fast kinetic chemical and physical reactions, makes it possible to synthesize significant quantities of material in a relatively short time. In the current approach aerosols of a silazane monomer, (CH3SiHNH)n, (n = 3 or 4), of mol. wt. 280–320, are injected into the beam of a cw industrial CO2 laser to obtain nanoscale ceramic powders. Injection of the aerosol into the laser-beam results in a high-temperature plume. Rapid condensation of the molecular precursor species emerging from the laser plume results in the formation of preceramic polymer particles, with an average diameter of 62 nm. One attractive feature of this process is that 70 wt.% of the liquid precursor is converted into nanoscale powders. Another feature is that only a further 10 wt.% loss occurs during post thermal treatment to form the end-product.

Synthesis of Amino-Functionalized Graphene Oxide/Azobenzene Polyimide and its Simulation of Optical Switches

2017 ◽  
Vol 231 (11-12) ◽  
Author(s):  
Tianlin Cao ◽  
Fanyu Zhao ◽  
Zulin Da ◽  
Fengxian Qiu ◽  
Dongya Yang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Near Infrared ◽  
Optical Switches ◽  
Attenuated Total Reflection ◽  
Functionalized Graphene ◽  
Visible Spectroscopy ◽  
Scanning Calorimetry ◽  
Functionalized Graphene Oxide ◽  
Uv Visible ◽  
532 Nm

AbstractIn this work, an amino-functionalized graphene oxide (AFGO) was synthesized by graphene oxide (GO) and ethylene diamine. A novel amino-functionalized graphene oxide/azobenzene polyimide (AFGO/ACPI) was synthesized with AFGO, azobenzene chromophore and pyromellitic dianhydride (PMDA). The structure, mechanical and thermal property of AFGO/ACPI were characterized and measured by fourier transform infrared, UV-visible spectroscopy, near-infrared spectrum, thermogravimetric analysis and differential scanning calorimetry. To obtain the refractive index of AFGO/ACPI at different temperature and wavelength (532 nm, 650 nm and 850 nm), the attenuated total reflection (ATR) method was used to measure, and thermo optic coefficients (dn/dT) were −7.22×10

scholarly journals Inverse problem for tripotential measures in the study of buried cavities

1996 ◽  
Vol 39 (1) ◽  
Author(s):  
P. Cosentino ◽  
D. Luzio ◽  
R. Martorana
Keyword(s):  
Apparent Resistivity ◽  
Random Noise ◽  
Source Parameters ◽  
Spherical Shape ◽  
Average Diameter ◽  
Unknown Parameters ◽  
Fundamental Parameters ◽  
Spherical Models ◽  
Source Models ◽  
Biased Estimates

This paper presents a solution to the inverse electrical problem for the interpretation of apparent resistivity anomalies due to empty buried cavities of quasi-spherical shape when tripotential measures are carried out. The anomalies of the apparent resistivities ra,rb andrg,and the composed resistivitiesrmand rt were previously calculated for a sufficient class of spherical models of resistivity anomalies. Then, for the whole class of models, some functionals of spatial distribution of the apparent and composed resistivity were identified and analyzed. They represent the average characteristics of the anomalies and, depending in a simple way on the fundamental parameters of the sources of the anomalies (average diameter and depth), they allow reliable estimates to be determined. Among the studied functionals, those allowing the most stable and less biased estimates of the anomaly source parameters are identified by numerical simulations with random noise perturbed data. Finally the trend of standard deviation and bias of the estimates of the unknown parameters were analyzed by varying the source models and the set of functionals used for the inversion.

Liquid exfoliation of graphene oxide nanoribbons using chemical assisted laser ablation

2021 ◽  
pp. 2140009
Author(s):  
Siddhant Dhongade ◽  
Pankaj Koinkar ◽  
Akihiro Furube ◽  
Satoshi Sugano
Keyword(s):  
Graphene Oxide ◽  
Laser Ablation ◽  
2D Materials ◽  
Visible Spectroscopy ◽  
Liquid Exfoliation ◽  
Graphene Oxide Nanoribbons ◽  
Laser Ablation Method ◽  
Structural Details ◽  
Uv Visible ◽  
Optical Applications

The interest toward two-dimensional (2D) materials is gradually increasing because of their structure at nanoscale and great importance for electronic and optical applications. In this study, we show the synthesis of graphene oxide (GO) micro-ribbons fabricated by chemical assisted-laser ablation method. In order to confirm the formation of GO, UV-visible spectroscopy (UV-vis) and Raman spectroscopy are used to observe the surface morphological feature and structural details. In addition, a possible mechanism for the growth of GO nanoribbon is discussed. This work indicates a new method to develop GO nanostructures and related nanomaterials.

scholarly journals One-Step Synthesis of Diamine-Functionalized Graphene Quantum Dots from Graphene Oxide and Their Chelating and Antioxidant Activities

Nanomaterials ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 104 ◽  
Author(s):  
Rabeb El-Hnayn ◽  
Laetitia Canabady-Rochelle ◽  
Christophe Desmarets ◽  
Lavinia Balan ◽  
Hervé Rinnert ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Graphene Oxide ◽  
Colloidal Stability ◽  
Antioxidant Activities ◽  
Graphene Quantum Dots ◽  
Average Diameter ◽  
Functionalized Graphene ◽  
One Step ◽  
Low Cytotoxicity ◽  
Health Applications

2,2’-(Ethylenedioxy)bis(ethylamine)-functionalized graphene quantum dots (GQDs) were prepared under mild conditions from graphene oxide (GO) via oxidative fragmentation. The as-prepared GQDs have an average diameter of ca. 4 nm, possess good colloidal stability, and emit strong green-yellow light with a photoluminescence (PL) quantum yield of 22% upon excitation at 375 nm. We also demonstrated that the GQDs exhibit high photostability and the PL intensity is poorly affected while tuning the pH from 1 to 8. Finally, GQDs can be used to chelate Fe(II) and Cu(II) cations, scavenge radicals, and reduce Fe(III) into Fe(II). These chelating and reducing properties that associate to the low cytotoxicity of GQDs show that these nanoparticles are of high interest as antioxidants for health applications.

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