DNA mediated Graphene Oxide (GO)-nanosheets dispersed supramolecular GO-DNA hydrogel: An efficient soft-milieu for simplistic synthesis of Ag-NPs@GO-DNA and Gram +ve/-ve bacteria-based Ag-NPs@GO-DNA-Bacteria nano-bio composites

2021 ◽  
pp. 117482
Author(s):  
Santanu Majumdar ◽  
Madhuri Ghosh ◽  
Suprabhat Mukherjee ◽  
Biswarup Satpati ◽  
Biswajit Dey
Keyword(s):  
Graphene Oxide ◽  
Ag Nps ◽  
Dna Hydrogel

scholarly journals Hydrothermal Synthesis of Silver Decorated Reduced Graphene Oxide (rGO) Nanoflakes with effective Photocatalytic Activity for Wastewater Treatment

2020 ◽  
Author(s):  
Muhammad Ikram ◽  
A. Raza ◽  
M. Imran ◽  
A. Ul-Hamid ◽  
S. Ali
Keyword(s):  
Photocatalytic Activity ◽  
Graphene Oxide ◽  
Electron Microscope ◽  
Reduced Graphene Oxide ◽  
Dye Degradation ◽  
Spherical Shape ◽  
Molecular Vibration ◽  
Homogeneous Distribution ◽  
Ag Nps ◽  
Reduced Graphene

Abstract Graphene oxide (GO) was obtained through modified hummers method and reduced graphene oxide (rGO) was acquired by employing heat treatment. Various concentrations (2.5, 5, 7.5 and 10 wt.%) of silver (Ag) were incorporated in GO nanosheets by adopting hydrothermal approach. Synthesized Ag decorated rGO photocatalyst Ag/rGO was characterized using X-ray diffraction (XRD) to determine phase purity and crystal structure. XRD patterns showed the formation of GO to Ag/rGO. Molecular vibration and functional groups were determined through Fourier Transform Infrared spectroscopy (FTIR). Optical properties and a decrease in bandgap with insertion of Ag were confirmed with UV-visible (Uv-vis.) spectrophotometer and Photoluminescence (PL). Electronic properties and disorders in carbon structures were investigated through Raman spectroscopy that revealed the existence of characteristic bands (D and G). Surface morphology of prepared samples was examined with Field Emission Scanning Electron Microscope (FESEM). Homogeneous distribution, size and spherical shape of Ag NPs over rGO sheets were further confirmed with the help of High-Resolution Transmission Electron Microscope (HR-TEM). Dye degradation of doped and undoped samples was examined through Uv-vis. spectra. Experimental results indicated that photocatalytic activity of Ag@rGO enhanced with increased doping ratio owing to diminished electron-hole pair recombination. Therefore, it is suggested that Ag@rGO can be used as a beneficial and superior photocatalyst to clean environment and wastewater.

scholarly journals A Novel Green Preparation of Ag/RGO Nanocomposites with Highly Effective Anticancer Performance

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3350
Author(s):  
Maqusood Ahamed ◽  
Mohd Javed Akhtar ◽  
M. A. Majeed Khan ◽  
Hisham A. Alhadlaq
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Green Synthesis ◽  
Orange Peel ◽  
Glutathione Depletion ◽  
Lung Fibroblasts ◽  
Normal Lung ◽  
Mechanistic Study ◽  
Ag Nps ◽  
Highly Effective

The efficacy of current cancer therapies is limited due to several factors, including drug resistance and non-specific toxic effects. Due to their tuneable properties, silver nanoparticles (Ag NPs) and graphene derivative-based nanomaterials are now providing new hope to treat cancer with minimum side effects. Here, we report a simple, inexpensive, and eco-friendly protocol for the preparation of silver-reduced graphene oxide nanocomposites (Ag/RGO NCs) using orange peel extract. This work was planned to curtail the use of toxic chemicals, and improve the anticancer performance and cytocompatibility of Ag/RGO NCs. Aqueous extract of orange peels is abundant in phytochemicals that act as reducing and stabilizing agents for the green synthesis of Ag NPs and Ag/RGO NCs from silver nitrate and graphene oxide (GO). Moreover, the flavonoid present in orange peel is a potent anticancer agent. Green-prepared Ag NPs and Ag/RGO NCs were characterized by UV-visible spectrophotometry, transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and dynamic light scattering (DLS). The results of the anticancer study demonstrated that the killing potential of Ag/RGO NCs against human breast cancer (MCF7) and lung cancer (A549) cells was two-fold that of pure Ag NPs. Moreover, the cytocompatibility of Ag/RGO NCs in human normal breast epithelial (MCF10A) cells and normal lung fibroblasts (IMR90) was higher than that of pure Ag NPs. This mechanistic study indicated that Ag/RGO NCs induce toxicity in cancer cells through pro-oxidant reactive oxygen species generation and antioxidant glutathione depletion and provided a novel green synthesis of Ag/RGO NCs with highly effective anticancer performance and better cytocompatibility.

Ultrasensitive Detection of Mitochondrial DNA Mutation by Graphene Oxide/DNA Hydrogel Electrode

2014 ◽  
Vol 24 (44) ◽  
pp. 6905-6913 ◽  
Author(s):  
Liping Sun ◽  
Nan Hu ◽  
Jian Peng ◽  
Liyu Chen ◽  
Jian Weng
Keyword(s):  
Mitochondrial Dna ◽  
Graphene Oxide ◽  
Ultrasensitive Detection ◽  
Mitochondrial Dna Mutation ◽  
Dna Mutation ◽  
Dna Hydrogel

Graphene Oxide Functionalized with Silver Nanoparticles and ZnO Synergic Nanocomposite as an Efficient Electrochemical Sensor for Diclofenac Sodium

NANO ◽  
2021 ◽  
Author(s):  
Saira Naz ◽  
Amjad Nisar ◽  
Lizhi Qian ◽  
Shafqat Hussain ◽  
Shafqat Karim ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Graphene Oxide ◽  
Diclofenac Sodium ◽  
Modified Electrodes ◽  
High Sensitivity ◽  
Cost Effective ◽  
Fast Response ◽  
Industrial Applications ◽  
Ag Nps ◽  
Enhanced Sensitivity

The development of a highly sensitive and selective electrocatalyst for the detection of diclofenac sodium (D.S.) has remained a great challenge. In this work, graphene oxide functionalized with silver nanoparticles and zinc oxide (Ag–ZnO–GO) electrocatalyst was developed and investigated for the detection of D.S. The Ag–ZnO–GO/glassy carbon electrode exhibits high sensitivity and fast response within 3[Formula: see text]s owing to the efficient oxidation of D.S. at a very low potential at 0.25[Formula: see text]V. Moreover, the electrode shows a low detection limit of 0.02[Formula: see text][Formula: see text]M ([Formula: see text]) and long-term stability. To explore the synergic effects, the measurements of D.S. using GO, ZnO and ZnO–GO modified electrodes were also performed. The results demonstrate that the Ag–ZnO–GO nanocomposite electrode exhibits enhanced sensitivity and selectivity compared to the other electrodes. In addition, the electrode reveals excellent results for D.S. detection in the real samples as well. The enhanced performance of the proposed electrode is attributed to the improved electron transfer ability and synergic effects of the plasmonic Ag NPs and ZnO–GO structure. It is expected that Ag–ZnO–GO composite is a promising candidate for the construction of cost-effective electrochemical biosensors for medical and industrial applications.

scholarly journals Femtosecond laser-assisted synthesis of silver nanoparticles and reduced graphene oxide hybrid for optical limiting

2018 ◽  
Vol 5 (7) ◽  
pp. 171436 ◽  
Author(s):  
Yang Yu ◽  
Lihe Yan ◽  
Mengmeng Yue ◽  
Huanhuan Xu
Keyword(s):  
Silver Nanoparticles ◽  
Graphene Oxide ◽  
Femtosecond Laser ◽  
Reduced Graphene Oxide ◽  
Femtosecond Laser Ablation ◽  
Optical Limiting ◽  
Femtosecond Laser Pulses ◽  
Ion Concentration ◽  
Ag Nps ◽  
Reduced Graphene

Reduced graphene oxide (rGO) functionalized with silver nanoparticles (Ag NPs) is prepared using a femtosecond laser ablation in liquids method. By ablating the mixed aqueous solutions of silver nitrate and graphene oxide (GO) using femtosecond laser pulses, Ag ions and GO are simultaneously reduced and well-dispersed Ag NPs supported on rGO are obtained. The effect of laser power, irritation time and Ag ion concentration on the optical property and morphology of the products are systematically studied. The nonlinear optical responses of the functionalized graphene are studied using a nanosecond Z-scan technique. The rGO hybrid shows an enhanced nonlinear absorption (NLA) effect compared with GO and rGO, and thus exhibits an excellent optical limiting (OL) property with very low activating threshold, which is estimated to be about 0.38 J cm −2 . The enhanced NLA effect in rGO hybrids makes it possible to fabricate solid-state optical limiter, improving the practicality of graphene materials in the OL area.

scholarly journals Graphene Oxide/Silver Nanocomposites as Antifouling Coating on Sensor Housing Materials

2021 ◽  
Author(s):  
Xiaoxue Zhang ◽  
Øyvind Mikkelsen
Keyword(s):  
Graphene Oxide ◽  
Fish Farming ◽  
Water Quality Monitoring ◽  
Sensor Data ◽  
Valuable Insight ◽  
Ag Nps ◽  
Biofilm Growth ◽  
Antifouling Coating ◽  
Antifouling Property ◽  
Housing Materials

AbstractThese days, sensors are widely used in a variety of underwater sites like marine monitoring, fish-farming and water quality monitoring. However, to achieve reliable sensor data from long-term monitoring in aqueous solution, several challenges still need to be solved. Biofilm formation both on sensor housings and membranes is among one of the most serious challenges, which strongly influences the sensor responds and the validity of the results. To prevent biofilm growth, a series of graphene oxide (GO)/silver nanoparticles (Ag NPs) nanocomposites (GOA) have been developed and coated on sensor housing materials, e.g. polypropylene. The antifouling property of the GOA nanocomposite has been demonstrated by antifouling tests using Halomonas. Pacifica (Baumann et al.) Dobson and Franzmann (ATCC® 27122) (H. Pacifica) and a mixture of marine algae. The antifouling property of GOA composites has been proved to be closely related to the dispersibility of Ag NP. The overall work might provide valuable insight into developing antifouling materials for sensors in general.

scholarly journals Application of Fe-graphene oxide nanocomposite to improve SERS intensity of polyaromatic hydrocarbons-=SUP=-*-=/SUP=-

2019 ◽  
Vol 127 (11) ◽  
pp. 827
Author(s):  
V. Rezaie Kahkhaie ◽  
M.H. Yousefi ◽  
M. Darbani ◽  
A. Mobashery
Keyword(s):  
Graphene Oxide ◽  
Iron Nanoparticles ◽  
Polyaromatic Hydrocarbons ◽  
Sem Analysis ◽  
Raman Shift ◽  
Raman Signal ◽  
Ag Nps ◽  
Sers Substrates ◽  
Complete Formation ◽  
Sers Intensity

Abstract Raman spectroscopy is used to provide a structural finger-print by which molecules can be identified. SERS technique offers many orders of magnitude enhancement in initial weak Raman signal of some molecules. To detect Raman signal of pyrene, magnetic properties of iron nanoparticles (Fe NPs) was employed along with graphene oxide (GO). Significant differences were discovered in performance of five different SERS substrates which were prepared using magnetized and non-magnetized Fe NPs-GO nanocomposites (FNRC) and Ag nanoparticles. UV-Vis, Raman and FE-SEM analysis presented complete formation of Ag-NPs, GO and FNRCs. The quantity of enhancement measured showed different enhancements from 1.09 up to 3.54 times for pyrene solution on magnetized Fe NP-GO nanocomposite. SERS enhancement showed a reverse relation with GO/Fe precursor rate. Raman shift suggested formation of new bonds. 2.017 RSD factor presented very fast performance only 10 seconds after irradiation of magnetized FNRCs.

scholarly journals Hydrothermal Synthesis of Silver Decorated Reduced Graphene Oxide (rGO) Nanoflakes with effective Photocatalytic Activity for Wastewater Treatment

2020 ◽  
Author(s):  
Muhammad Ikram ◽  
Ali Raza ◽  
Muhammad Imran ◽  
Anwar Ul-Hamid ◽  
Atif Shahbaz ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Graphene Oxide ◽  
Electron Microscope ◽  
Reduced Graphene Oxide ◽  
Dye Degradation ◽  
Spherical Shape ◽  
Molecular Vibration ◽  
Homogeneous Distribution ◽  
Ag Nps ◽  
Reduced Graphene

Abstract Graphene oxide (GO) was obtained through modified hummers method and reduced graphene oxide (rGO) was acquired by employing heat treatment. Various concentrations (2.5, 5, 7.5 and 10 wt.%) of silver (Ag) were incorporated in GO nanosheets by adopting hydrothermal approach. Synthesized Ag decorated rGO photocatalyst Ag/rGO was characterized using X-ray diffraction (XRD) to determine phase purity and crystal structure. XRD patterns showed the formation of GO to Ag/rGO. Molecular vibration and functional groups were determined through Fourier Transform Infrared spectroscopy (FTIR). Optical properties and a decrease in bandgap with insertion of Ag were confirmed with UV-visible (Uv-vis.) spectrophotometer and Photoluminescence (PL). Electronic properties and disorders in carbon structures were investigated through Raman spectroscopy that revealed the existence of characteristic bands (D and G). Surface morphology of prepared samples was examined with Field Emission Scanning Electron Microscope (FESEM). Homogeneous distribution, size and spherical shape of Ag NPs over rGO sheets were further confirmed with the help of High-Resolution Transmission Electron Microscope (HR-TEM). Dye degradation of doped and undoped samples was examined through Uv-vis. spectra. Experimental results indicated that photocatalytic activity of Ag@rGO enhanced with increased doping ratio owing to diminished electron-hole pair recombination. Therefore, it is suggested that Ag@rGO can be used as a beneficial and superior photocatalyst to clean environment and wastewater.

Tuning the efficiency of CoFe2O4@rGO composite by Encapsulating Ag Nanoparticles for the photocatalytic degradation of Methyl violet dye and Energy storage systems

2021 ◽  
Author(s):  
S. Vijayalakshmi ◽  
Elanthamilan Elaiyappillai ◽  
Princy Merlin Johnson ◽  
Sharmila Lydia I
Keyword(s):  
Silver Nanoparticles ◽  
Graphene Oxide ◽  
Energy Storage ◽  
Ag Nanoparticles ◽  
Storage Systems ◽  
Methyl Violet ◽  
Ag Nps ◽  
Reduced Graphene ◽  
Simple Chemical ◽  
Co Precipitation

In the present work, silver nanoparticles encapsulated CoFe2O4@reduced Graphene oxide composite (Ag NPs/CoFe2O4@rGO) was prepared via a simple chemical co-precipitation technique. The formation of the materials was confirmed by various...

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