Synthesis and spectroscopic studies of stable aqueous dispersion of silver nanoparticles

Author(s):  
Reda M. El-Shishtawy ◽  
Abdullah M. Asiri ◽  
Maha M. Al-Otaibi
Author(s):  
Mohd. Sajid Ali ◽  
Hamad A. Al-Lohedan ◽  
M.Z.A. Rafiquee ◽  
Ayman M. Atta ◽  
Abdurrahman O. Ezzat

Dose-Response ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. 155932582110113
Author(s):  
Pamela Nair Silva-Holguín ◽  
Simón Yobanny Reyes-López

Researchers are currently looking for materials that are stable, functional, aesthetic, and biocompatible without infections. Therefore, there is a great interest in obtaining a material that has a balance between aesthetic, biological, mechanical, and functional factors, which can be used as an infection control material. The addition of hydroxyapatite to alumina make highly bioactive scaffolds with mechanical strength. Biomedical applications require antibacterial properties; therefore, this idea leads to great interest in the development of new synthetic routes of ceramic biomaterials that allow the release of nanoparticles or metal ions. This investigation presents the obtention of alumina-hydroxyapatite spheres doped with silver nanoparticles with antibacterial effect against various Gram-positive and negative bacteria related to drug-resistance infections. The microstructural and spectroscopic studies demonstrate that the spheres exhibit a homogeneous structure and crystal hydroxyapatite and silver nanoparticles are observed on the surface. The antimicrobial susceptibility was verified with the agar diffusion and turbidimetry methods in Gram-negative ( Escherichia coli and Pseudomonas aeruginosa) and Gram-positive ( Staphylococcus aureus and Bacillus subtilis) bacteria. All bacteria used were susceptible to the alumina-hydroxyapatite-silver spheres even at lower silver concentration. The composites have a higher possibility for medical applications focused on the control of drug-resistance microorganisms.


2018 ◽  
Vol 7 (1) ◽  
pp. 30-37 ◽  
Author(s):  
Ramesh Vinayagam ◽  
Thivaharan Varadavenkatesan ◽  
Raja Selvaraj

Abstract:An environmentally benign method to synthesize silver nanoparticles (SNPs) using the leaf extract ofBridelia retusawas developed. The UV-Vis absorption spectrum of the synthesized SNPs displayed a surface plasmon peak at 420 nm. Scanning electron microscopy (SEM) revealed the irregular shaped nanoparticles, and energy dispersive X-ray (EDX) ascertained the presence of metallic silver by showing a strong signal at 3 eV. The crystalline structure of metallic silver was confirmed by X-ray diffraction (XRD). The mean size of the SNPs was calculated as 16.21 nm. Fourier infrared (FT-IR) spectroscopic studies displayed specific bands for various functional groups and affirmed the function of reduction and stabilization of SNPs. The stability was endorsed by the zeta potential value of −18.1 mV. The results evidenced that this leaf extract-mediated synthesis method is eco-friendly, rapid, and cheap. The catalytic power of the SNPs was investigated for Rhodamine B dye degradation. The SNPs completely degraded Rhodamine B within 9 min; thus, the dye degradation process was very rapid. The pseudo-first order degradation constant was found out to be 0.1323 min−1. This paves the way for the future development of novel nano-catalysts to reduce environmental pollution.


2020 ◽  
pp. 152808372092473 ◽  
Author(s):  
Suchart Siengchin ◽  
Pawinee Boonyasopon ◽  
Vajja Sadanand ◽  
Anumakonda Varada Rajulu

In the present work, nanocomposite cellulose fabrics with in situ generated silver nanoparticles were prepared by bioreduction method employing aqueous dispersion of low-cost natural turmeric powder as a reducing agent and different concentrated aqueous AgNO3 as source solutions. The prepared nanocomposite cellulose fabrics were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, and antibacterial tests. The nanocomposite cellulose fabrics had roughly spherical silver nanoparticles in the size range of 41–130 nm with an overall average of 78 nm. The X-ray analysis indicated the generation of both silver nanoparticles and Ag2O nanoparticles in the nanocomposite cellulose fabrics. The nanocomposite cellulose fabrics retained the generated AgNPs even after repeated detergent washings. The prepared nanocomposite cellulose fabrics exhibited excellent antibacterial activity against both the Gram-negative and Gram-positive bacteria and hence can be considered as antibacterial hospital-bed materials, apparels, etc.


2011 ◽  
Vol 257 (24) ◽  
pp. 10607-10612 ◽  
Author(s):  
M.A. Majeed Khan ◽  
Sushil Kumar ◽  
Maqusood Ahamed ◽  
Salman A. Alrokayan ◽  
M.S. Alsalhi ◽  
...  

2010 ◽  
Vol 356 (23-24) ◽  
pp. 1097-1101 ◽  
Author(s):  
Z. Pan ◽  
A. Ueda ◽  
R. Aga ◽  
A. Burger ◽  
R. Mu ◽  
...  

2004 ◽  
Vol 846 ◽  
Author(s):  
Tsunenobu Onodera ◽  
Hidetoshi Oikawa ◽  
Hitoshi Kasai ◽  
Hachiro Nakanishi ◽  
Takashi Sekiguchi

ABSTRACTNoble metal-coated polydiacetylene (PDA) nanocrystals are expected to enlarge effective third-order nonlinear optical susceptibility, owing to the enhancement of optical electric field induced by localized surface plasmon. The surface of PDA nanocrystals was decorated with silver nanoparticles, and the linear optical properties were investigated. The well-defined PDA nanocrystals were first prepared by the conventional reprecipitation method as an aqueous dispersion. The following two-steps of reduction methods, namely, seed deposition and seed growth, enabled higher silver coverage on the surface of PDA nanocrystals. Silver fine seeds were successfully deposited on the PDA surface by particularly employing an anionic surfactant as a binder. The extinction spectra of the PDA nanocrystals covered with silver exhibited the red-shift and broadening of surface plasmonic peak for silver nanoparticles, which would indicate the interaction among silver nanoparticles on the same PDA nanocrystal. In addition, the red-shift of excitonic peak for PDA nanocrystals was observed, resulting from the changes of dielectric properties around PDA nanocrystal. Both spectral changes would have an influence on nonlinear optical properties of PDA nanocrystal.


2021 ◽  
Author(s):  
S Shanthi ◽  
V. Uma Maheshwari Nallal ◽  
Krishnan Anand ◽  
Balasubramani Ravindran ◽  
Soon Woong Chang ◽  
...  

Abstract Bio-inspired nanoparticle synthesis has attracted substantial interest among the scientific society owing to its eco-friendly and non-toxic nature. In the present study, Silver nanoparticles (AgNPs) were synthesized using high altitude squamulose lichen – Cladonia subradiata and characterized using different techniques. The antioxidant and anticandida activity of AgNPs were evaluated using multiple in-vitro assays. In-silico molecular docking analysis and in-vitro cytotoxic assay was performed to determine the anti-cancer potential of synthesized AgNPs. The results of the spectroscopic studies revealed the successful synthesis of AgNPs and the presence of different functional groups suggesting the involvement of phytocompounds in the reduction and capping of AgNPs. The average size of the AgNPs was 20 nm and predominantly spherical in shape. AgNPs demonstrated excellent DPPH free radicals scavenging activity with an IC50 value of 7.51 ± 0.4 µg/mL. C.albicans was identified as the most susceptible strain from the anticandida studies. Usnic acid and Pulvinic acid exhibited low binding energies and showed excellent inhibition interaction with EGFR lung cancer protein. The in-vitro cytotoxic results were impressive with an IC50 value of 28.75 µg/mL for A549 lung cancer cells treated with AgNPs. Thus, the study demonstrates the effective and non-toxic synthesis of AgNPs using a less explored lichen extract as a promising anticandida and anticancer agent in the field of nano-medicine.


2021 ◽  
Vol 37 (1) ◽  
pp. 109-115
Author(s):  
S. Vidhya ◽  
A. Leema Rose ◽  
F. Janeeta Priya ◽  
T. Keerthana ◽  
R. Priyadharshini

The potential inhibitory action of herbals plays an indispensable role in modern medicine. The struvite crystal is an infectious stone related to urinary tract infection, hence the present study highlighted the anti-urolithiatic potential of Terminalia chebula bark mediated silver nanoparticles. Silver nanoparticles formation was confirmed by SPR band at 437nm. FT-IR spectroscopic studies suggested that phytoconstituents are primarily responsible for the reduction and capping of silver nanoparticles. TEM and XRD analysis revealed that the uniformity in shape and crystalline nature of T. chebula mediated silver nanoparticles. The single gel diffusion method was adopted to found the inhibition action of T.chebula mediated silver nanoparticles in struvite crystals. The inhibition efficiency was found to be 87.9 %, indicated that T. chebula mediated silver nanoparticles was a good inhibitor for the struvite crystals. The shift in band values of FTIR spectra confirms that the phyto constituents present in T. chebula bark is responsible for the anti-urolithiatic activity.


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