Green Route for Silver Nanoparticles Synthesis by Raphanus Sativus Extract in a Continuous Flow Tubular Microreactor

2017 ◽  
Vol 16 (01) ◽  
pp. 1650019 ◽  
Author(s):  
P. D. Jolhe ◽  
B. A. Bhanvase ◽  
V. S. Patil ◽  
S. H. Sonawane

The present work deals with the investigation of the greener route for the production of silver nanoparticles using Raphanus sativus (R. sativus) bioextract in a continuous flow tubular microreactor. The parameters affecting the particle size and distribution were investigated. From the results obtained it can be inferred that the ascorbic acid (reducing agent) present in the R. sativus bioextract is responsible for the reduction of silver ions. At optimum condition, the particle size distribution of nanoparticles is found between 18[Formula: see text]nm and 39[Formula: see text]nm. The absorbance value was found to be decreased with an increase in the diameter of the microreactor. It indicates that a number of nuclei are formed in the micrometer sized (diameter) reactor because of the better solute transfer rate leading to the formation of large number of silver nanoparticles. The study of antibacterial activity of green synthesized silver nanoparticles shows effective inhibitory activity against waterborne pathogens, Shegella and Listeria bacteria.

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Antonio M. Brito-Silva ◽  
Luiz A. Gómez ◽  
Cid B. de Araújo ◽  
André Galembeck

Poly(vinyl-pyrrolidone) (PVP) stabilized silver nanoparticles with an average particle size ranging from 4.3 to 4.9 nm were synthesized by laser ablation in preformed colloids in methanol, acetone, ethylene glycol, and glycerin. Aqueous colloids obtained using PVP, poly(vinyl-alcohol) (PVA), and sodium citrate as stabilizing agents also lead to a good control over particle size distribution. Silver ions were reduced with sodium borohydride. The smaller average particle size and narrower dispersivity in comparison to previously reported data were ascribed to the relatively small size of the particles formed in the chemical reduction step, laser fluence, and the use of PVP, which was not previously used as the stabilizing agent in “top-down” routes. The surface plasmon resonance band maximum wavelength shifted from 398 nm in methanol to 425 nm in glycerin. This shift must be due to solvent effects since all other variables were the same.


2014 ◽  
Vol 2 (3) ◽  
pp. 305-310
Author(s):  
N. Packialakshmi ◽  
S. Naziya

The aim of this study was to synthesis of silver nanoparticles in the aqueous stem extracts of Caralluma fimbriyata and investigate its antibacterial activity. Nanoparticles are being used in many commercial applications. It was found that aqueous silver ions can be reduced by aqueous stem extracts of plant parts to generate to extremely stable silver nanoparticles in water. The chemical groups studied using FT-IR analysis. Green synthesized silver nanoparticles showed zone of inhibition against isolated gram positive and gram negative bacteria. DOI: http://dx.doi.org/10.3126/ijasbt.v2i3.10796Int J Appl Sci Biotechnol, Vol. 2(3): 305-310  


2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Hessa H. Al-Rasheed ◽  
Kholood A. Dahlous ◽  
Essam N. Sholkamy ◽  
Sameh M. Osman ◽  
Omar H. Abd-Elkader ◽  
...  

Herein, we described the modification of chitosan with cyanuric chloride as a mediator for preparation of chitosan-s-triazinyl-bis(2-aminomethylpyridine) and chitosan-s-triazinyl-bis(8-oxyquinoline) derivatives to be used as reagents for preparation of silver nanoparticles under ecofriendly conditions. These two reagents are convenient and effective for reduction of silver ions to silver nanoparticles with particle size less than 10 nm that might be suitable for industrial and medicinal applications. The formation and particle size of AgNPs are characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), scanning electron microscope (SEM), and energy-dispersive X-ray analysis (EDX). The antimicrobial activity of the two modified chitosan-s-triazine-AgNPs was evaluated against activities against Gram-positive bacteria (M. luteus ATCC 10240 and MRSA ATCC 43300), Gram-negative bacteria (E. coli ATCC 25922 and P. aeruginosa ATCC 75853), and C. albicans. The results showed that chitosan-s-triazinyl-bis(2-aminomethylpyridine) AgNPs showed high antimicrobial activities against all the tested microorganisms, while their analogous chitosan-s-triazinyl-bis(8-oxyquinoline) AgNPs showed moderate activities.


2014 ◽  
Vol 575 ◽  
pp. 36-40 ◽  
Author(s):  
Nor Ain Ramli ◽  
Junaidah Jai ◽  
Noorsuhana Mohd Yusof

In this research, green synthesis of silver nanoparticles using elaeis guineensis leaves extract was investigated and the effect of reaction time in reduction mechanism and particle size is studied. UV-visible sprectrophotometer was used to monitored the reduction reaction of silver ions to silver nanoparticles and formation of silver nanoparticles shown at 15 minutes. Transmission electron microscopy (TEM) and field emission scanning electron microcopy (FESEM) shows polydispersed and irregular shape of silver nanoparticles with aggregation. Further confirms the formation of silver nanoparticles by energy dispersive x-ray analysis (EDAX). From this research, it was found that the increasing reaction time increases the rate of reduction reaction of silver ions.


2019 ◽  
Vol 19 (02) ◽  
pp. 1950009
Author(s):  
Parya Soltani-Horand ◽  
Hamideh Vaghari ◽  
Jahanbakhsh Soltani-Horand ◽  
Mohammad Adibpour ◽  
Hoda Jafarizadeh-Malmiri

Fungi extracellular synthesis of silver nanoparticles (AgNPs) using Aspergillus flavus mycelia extract was evaluated. Fourier transform-infrared spectroscopy revealed the presence of hydroxyl and amide I groups in the prepared fungi mycelia extract which those had key roles in the reduction of silver ions and stabilizing of the formed AgNPs. Response surface methodology (RSM) has been used to optimize and evaluate the effects of the prepared mycelia extract amount (5–7[Formula: see text]mL) and autoclave heating time (10–20[Formula: see text]min) on the particle size of the synthesized AgNPs. Obtained results revealed that the spherical mono-dispersed AgNPs with high stability were synthesized using 6[Formula: see text]mL of fungal mycelia extract and hydrothermally heating for 15[Formula: see text]min. At this obtained optimum synthesis conditions, broad emission peaks ([Formula: see text], mean particle size, concentration and zeta potential values for the fabricated AgNPs were 450[Formula: see text]nm, 44[Formula: see text]nm, 72[Formula: see text]ppm and [Formula: see text][Formula: see text]mV, respectively. The synthesized AgNPs also indicated high antibacterial activity against both Gram positive and negative bacteria.


Author(s):  
Vidyasagar G M ◽  
Shankaravva B ◽  
R Begum ◽  
Imrose ◽  
Sagar R ◽  
...  

Microorganisms like fungi, actinomycetes and bacteria are considered nanofactories and are helpful in the production of nanoparticles useful in the welfare of human beings. In the present study, we investigated the production of silver nanoparticles from Streptomyces species JF714876. Extracellular synthesis of silver nanoparticles by Streptomyces species was carried out using two different media. Silver nanoparticles were examined using UV-visible, IR and atomic force microscopy. The size of silver nanoparticles was in the range of 80-100 nm. Antimicrobial activity of silver nanoparticle against bacteria such as E. coli, S. aureus, and dermatophytes like T. rubrum and T. tonsurans was determined. Thus, this study suggests that the Streptomyces sp. JF741876 can produce silver ions that can be used as an antimicrobial substance.


Sign in / Sign up

Export Citation Format

Share Document