Charge State of Metallic Nanoparticles on a Conducting Substrate

2019 ◽  
Vol 61 (10) ◽  
pp. 1683-1689
Author(s):  
D. S. Il’yushchenkov ◽  
V. M. Kozhevin ◽  
S. A. Gurevich
2015 ◽  
Vol 57 (9) ◽  
pp. 1710-1714 ◽  
Author(s):  
D. S. Il’yushchenkov ◽  
V. M. Kozhevin ◽  
S. A. Gurevich

2020 ◽  
Vol 92 (2) ◽  
pp. 20101
Author(s):  
Behnam Kheyraddini Mousavi ◽  
Morteza Rezaei Talarposhti ◽  
Farshid Karbassian ◽  
Arash Kheyraddini Mousavi

Metal-assisted chemical etching (MACE) is applied for fabrication of silicon nanowires (SiNWs). We have shown the effect of amorphous sheath of SiNWs by treating the nanowires with SF6 and the resulting reduction of absorption bandwidth, i.e. making SiNWs semi-transparent in near-infrared (IR). For the first time, by treating the fabricated SiNWs with copper containing HF∕H2O2∕H2O solution, we have generated crystalline nanowires with broader light absorption spectrum, up to λ = 1 μm. Both the absorption and photo-luminescence (PL) of the SiNWs are observed from visible to IR wavelengths. It is found that the SiNWs have PL at visible and near Infrared wavelengths, which may infer presence of mechanisms such as forbidden gap transitions other can involvement of plasmonic resonances. Non-radiative recombination of excitons is one of the reasons behind absorption of SiNWs. Also, on the dielectric metal interface, the absorption mechanism can be due to plasmonic dissipation or plasmon-assisted generation of excitons in the indirect band-gap material. Comparison between nanowires with and without metallic nanoparticles has revealed the effect of nanoparticles on absorption enhancement. The broader near IR absorption, paves the way for applications like hyperthermia of cancer while the optical transition in near IR also facilitates harvesting electromagnetic energy at a broad spectrum from visible to IR.


2017 ◽  
Vol 13 (2) ◽  
pp. 4671-4677 ◽  
Author(s):  
A. M. Abdelghany ◽  
A.H. Oraby ◽  
Awatif A Hindi ◽  
Doaa M El-Nagar ◽  
Fathia S Alhakami

Bimetallic nanoparticles of silver (Ag) and gold (Au) were synthesized at room temperature using Curcumin. Reduction process of silver and gold ions with different molar ratios leads to production of different nanostructures including alloys and core-shells. Produced nanoparticles were characterized simultaneously with FTIR, UV/vis. spectroscopy, transmission electron microscopy (TEM), and Energy-dispersive X-ray (EDAX). UV/vis. optical absorption spectra of as synthesized nanoparticles reveals presence of surface palsmon resonance (SPR) of both silver at (425 nm) and gold at (540 nm) with small shift and broadness of gold band after mixing with resucing and capping agent in natural extract which suggest presence of bimetallic nano structure (Au/Ag). FTIR and EDAX data approve the presence of bimetallic nano structure combined with curcumin extract. TEM micrographs shows that silver and gold can be synthesized separately in the form of nano particles using curcumin extract. Synthesis of gold nano particles in presence of silver effectively enhance and control formation of bi-metallic structure.


Author(s):  
Anikate Sood ◽  
Shweta Agarwal

Nanotechnology is the most sought field in biomedical research. Metallic nanoparticles have wide applications in the medical field and have gained the attention of various researchers for advanced research for their application in pharmaceutical field. A variety of metallic nanoparticles like gold, silver, platinum, palladium, copper and zinc have been developed so far. There are different methods to synthesize metallic nanoparticles like chemical, physical, and green synthesis methods. Chemical and physical approaches suffer from certain drawbacks whereas green synthesis is emerging as a nontoxic and eco-friendly approach in production of metallic nanoparticles. Green synthesis is further divided into different approaches like synthesis via bacteria, fungi, algae, and plants. These approaches have their own advantages and disadvantages. In this article, we have described various metallic nanoparticles, different modes of green synthesis and brief description about different metabolites present in plant that act as reducing agents in green synthesis of metallic nanoparticles. 


2018 ◽  
Vol 18 (11) ◽  
pp. 1020-1029 ◽  
Author(s):  
Aftab Aslam P. Khan ◽  
Anish Khan ◽  
Abdullah M. Asiri ◽  
Ghulam Md. Ashraf ◽  
Basma G. Alhogbia

Author(s):  
Amer Imraish ◽  
Afnan Al-Hunaiti ◽  
Tuqa Abu-Thiab ◽  
Abed Al-Qader Ibrahim ◽  
Eman Hwaitat ◽  
...  

Background: The growing unsatisfaction toward the available traditional chemotherapeutic agents enhanced the need to develop new methods for obtaining materials with more effective and safe anti-cancer properties. Over the past few years, usage of metallic nanoparticles has been a target for researchers of different scientific and commercial fields due to their tiny sizes, environment friendly properties and wide range applications. To overcome the obstacles of traditional physical and chemical methods for synthesis of such nanoparticles, a new less expensive and eco-friendly method has been adopted using natural existing organisms as a reducing agent to mediate synthesis of the desired metallic nanoparticles from their precursors, a process called green biosynthesis of nanoparticles. Objective: Here in the present study, zinc iron bimetallic nanoparticles (ZnFe2O4) were synthesized via an aqueous extract of Boswellia Carteri resin mixed with zinc acetate and iron chloride precursors, and they were tested for their anticancer activity. Methods: Various analytic methods were applied for the characterization of the Phyto synthesized ZnFe2O4 and they were tested for their anticancer activity against MDA-MB-231, K562, MCF-7 cancer cell lines and normal fibroblasts. Results: Our results demonstrate the synthesis of cubic structured bimetallic nanoparticles ZnFe2O4 with an average diameter 10.54 nm. MTT cytotoxicity assay demonstrate that our phyto-synthesized ZnFe2O4 nanoparticles exhibited a selective and potent anticancer activity against K562 and MDA-MB-231 cell lines with IC50 values 4.53 µM and 4.19 µM, respectively. Conclusion: In conclusion, our bio synthesized ZnFe2O4 nano particles show a promising environmentally friendly of low coast chemotherapeutic approach against selective cancers with a predicted low adverse side effect toward normal cells. Further in vivo advanced animal research should be done to execute their applicability in living organisms.


Author(s):  
Geetanjali Singh ◽  
Pramod Kumar Sharma ◽  
Rishabha Malviya

Aim/Objective: The author writes the manuscript by reviewing the literatures related to the biomedical application of metallic nanoparticles. The term metal nanoparticles are used to describe the nanosized metals with the dimension within the size range of 1-100 nm. Methods: The preparation of metallic nanoparticles and their application is an influential area for research. Among various physical and chemical methods (viz. chemical reduction, thermal decomposition, etc.) for synthesizing silver nanoparticles, biological methods have been suggested as possible eco-friendly alternatives. The synthesis of metallic nanoparticles is having many problems inclusive of solvent toxicity, the formation of hazardous byproducts and consumption of energy. So it is important to design eco-friendly benign procedures for the synthesis of metallic nanoparticles. Results: From the literature survey, we concluded that metallic nanoparticles have applications in the treatment of different diseases. Metallic nanoparticles are having a great advantage in the detection of cancer, diagnosis, and therapy. And it can also have properties such as antifungal, antibacterial, anti-inflammatory, antiviral and anti-angiogenic. Conclusion: In this review, recent upcoming advancement of biomedical application of nanotechnology and their future challenges has been discussed.


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