Biofabrication Of Silver Nanoparticles Research Articles

Bio-Fabrication of Silver Nanoparticles from Vigna Mungo Seed Extract and its Effect on the Fungus, Fusarium Oxysporum in Vitro

Bio-Fabrication of Silver Nanoparticles from Vigna Mungo Seed Extract and its Effect on the Fungus, Fusarium Oxysporum in Vitro

Almond leaves for the one-pot Biofabrication of silver nanoparticles: Characterization and larvicidal application

Almond leaves for the one-pot Biofabrication of silver nanoparticles: Characterization and larvicidal application

Biofabricated silver nanoparticles incorporated polymethyl methacrylate as a dental adhesive material with antibacterial and antibiofilm activity against Streptococcus mutans.

In this study, polymethyl methacrylate (PMMA) thin films incorporated with biofabricated silver nanoparticles were used to evaluate the in vitro antimicrobial and antibiofilm activity against the cariogenic bacterium Streptococcus mutans. For this, silver nanoparticles (AgNPs) were generated using Bacillus amyloliquefaciens SJ14 culture (MAgNPs) and extract from Curcuma aromatica rhizome (CAgNPs). The AgNPs were further characterized by UV-Vis spectroscopy and high-resolution transmission electron microscopy. The minimum inhibitory concentration, minimum bactericidal concentration and antibiofilm activity of AgNPs against S. mutans were also assessed. Here, MAgNPs were found to have superior antimicrobial activity when compared to CAgNPs. TheMAgNPs and CAgNPs also demonstrated 99% and 94% inhibition of biofilm formation of S. mutans at concentrations of 3µg/mL and 50µg/mL, respectively. The AgNPs were further incorporated into PMMAthin films using solvent casting method. The thin films were also characterized by scanning electron microscopy and UV-Vis spectroscopy. Subsequently, both PMMA/MAgNPs and PMMA/CAgNPs nanocomposite thin films were subjected to antimicrobial and antibiofilm analysis. Themicrobicidal activity wasfound to be higher for the PMMA/MAgNPs thin film, which highlights the potency of microbially synthesized AgNPs as excellent agents to inhibitcariogenic bacteria from colonisingdental restorative material.

Biofabrication of silver nanoparticles using bacteria from mangrove swamp.

The last decade has observed a rapid advancement in utilising biological system towards bioremediation of metal ions in the form of respective metal nanostructures or microstructures. The process may also be adopted for respective metal nanoparticle biofabrication. Among different biological methods, bacteria-mediated method is gaining great attention for nanoparticle fabrication due to their eco-friendly and cost-effective process. In the present study, silver nanoparticle (AgNP) was synthesised via continuous biofabrication using Aeromonas veronii, isolated from swamp wetland of Sunderban, West Bengal, India. The biofabricated AgNP was further purified to remove non-conjugated biomolecules using size exclusion chromatography, and the purified AgNPs were characterised using UV-visible spectroscopy, X-ray diffraction, field emission scanning electron microscopy and transmission electron microscopy (TEM). Additionally, the presence of proteins as capping and stabilising agents was confirmed by the amide-I and amide-II peaks in the spectra obtained using attenuated total reflection Fourier transform infrared spectroscopy. The size of biofabricated AgNP was 10-20 nm, as observed using TEM. Additionally, biofabricated AgNP shows significant antibacterial potential against E. coli and S. aureus. Hence, biofabricated AgNP using Aeromonas veronii, which found resistant to a significant concentration of Ag ion, showed enhanced antimicrobial activity compared to commercially available AgNP.

Biofabrication of silver nanoparticles and their combined effect with low intensity ultrasound for treatment of lung cancer

Ablation treatments are the minimally invasive surgical procedures that are used to treat early stage cancers. High intensity ultrasonic treatments that are used to treat solid cancers are not much successful in differentiating between healthy and cancerous cells. In this study, a method of combining ultrasound treatment with Garcinia mangostana bark extract mediated silver nanoparticles (AgNPs) was extended by making use of human lung epithelial cells, that could preferentially destruct the cancerous cells. Flow cytometry analysis is used to study the effect of ultrasound and AgNPs on cancerous (A549) cell lines and healthy (BEAS-2B) lung cells by means of counting viable cells (Q4). These experimental data showed a minor decline in the percentage of living cells from (66.8 ± 3.2) to (56 ± 6.2) % after the addition of bark extract synthesized AgNPs to the US-treated normal BEAS- 2B cell lines. However, the percentage of live A549 cancer cells presented a significant reduction from (61.4 ± 4.2) % for US-treated cells to (28.7 ± 6.4) % for the combination treatment of US with AgNPs. This study conducted against various cell lines denoted that nanoparticle-assisted ultrasound therapy (NAUT) could serve as an effective novel means for targeted destruction of cancer cells.

Bio fabrication of silver nanoparticles as an effective wound healing agent in the wound care after anorectal surgery

Nowadays biological mediated syntheses of metal nanoparticles were utilized for various life caring applications. Our research group utilized Delonix elata leaf aqueous extract for the synthesis of silver nanoparticles. Further the synthesized silver nanoparticles were subjected for various characterization techniques which resulted in spherically agglomerated with biological components entrapped in it and also with average particle size of 36nm were studied and reported. Later the synthesized silver nanoparticles were subjected for wound healing property by size of measured lessions and body weight which results in better wound healing property were studied and discussed.

Bio-fabrication of silver nanoparticles by phycocyanin, characterization, in vitro anticancer activity against breast cancer cell line and in vivo cytotxicity

In recent decades, researchers were attracted towards cyanobacterial components which are potential low-cost biological reagents for silver nanoparticle biosynthesis. This article describes the biological synthesis of silver nanoparticles using a proteinaceous pigment phycocyanin extracted from Nostoc linckia as reducing agent. The synthesized silver nanoparticles have a surface plasmon resonance band centered at 425 nm. Face-centered central composite design used for optimization of silver nanoparticles (AgNPs) biosynthesis using phycocyanin. The maximum AgNPs biosynthesis obtained using the optimized four variables, initial pH level (10), AgNO3 concentration (5 mM), phycocyanin pigment concentration (1 mg/mL) and incubation period (24 h) was 1100.025 µg/mL. The TEM analysis of AgNPs showed spherical nanoparticles with mean size between 9.39 to 25.89 nm. FTIR spectra showed major peaks of proteins involved in AgNPs biosynthesis by identifying different functional groups involved in effective capping of AgNPs. The biosynthesized AgNPs significantly inhibited the growth of medically important pathogenic Gram-positive (Staphylococcus aureus), Gram-negative bacteria (Pseudomonas aeruginosa, E. coli and Klebsiella pneumonia). The synthesized AgNPs exhibited effective cytotoxic activity against MCF-7 and the inhibitory concentration (IC50) was recorded at 27.79 ± 2.3 µg/mL. The in vivo studies clearly indicated that AgNPs has a capacity to inhibit the growth of tumor in Ehrlich ascites carcinoma bearing mice.

Anthelmintic effect of biofabricated silver nanoparticles using Ziziphus jujuba leaf extract on nutritional status of Haemonchus contortus

The present work was aimed to evaluate the efficacy of biofabricated silver nanoparticles (AgNPs) synthesized by using the aqueous extract of Ziziphus jujuba leaves against a small ruminant gastrointestinal nematode, Haemonchus contortus. AgNPs characterization was done through UV–vis spectral analysis, scanning and transmission electron microscopy and X-ray diffraction study, indicating synthesis of spherical and extremely small (28–44nm) nanoparticles. In vitro anthelmintic assay was based on egg hatch assay (EHA) and adulticidal study. The highest concentration of AgNPs induced 91±1.76 percent egg hatch inhibition. IC50 and IC90 values for EHA were 0.007ppm and 7.71ppm following AgNPs treatment and 301.83ppm and 849.43ppm with Z. jujuba aqueous leaf extract. In vitro adulticidal assay showed LC50 and LC90 values to be 15.29ppm and 33.87ppm with AgNPs while 942.68ppm and 2047.50ppm following exposure with Z. jujuba leaf extract. Distinct alterations were also noticed in egg morphology. Moreover, nutritional status of H. contortus was greatly influenced by AgNPs treatments as evident from significantly (P<0.05) reduced levels of glycogen, lipid and proteins depicting 5.69–21.81% depletion in adult worms. To our knowledge these results depict for the first time that Z. Jujuba possesses anthelmintic as well as reducing properties for AgNPs synthesis which altered nutritional parameters thus could serve as a candidate anthelmintic agent for controlling life threatening H. contortus infections in small ruminants.

Bioremediation potential of arsenic by non-enzymatically biofabricated silver nanoparticles adhered to the mesoporous carbonized fungal cell surface of Aspergillus foetidus MTCC8876

Our study aiming for the diminution of arsenic concentration in arsenic contaminated aqua environment by using novel adsorbents based on bio-fabricated silver nanoparticles on a fungal cell surface. Bioreduction of silver ion was done in a non-enzymatic manner in presence of the biomass of fungus Aspergillus foetidus MTCC8876. Aspergillus spp. cells were harvested following the bioreduction and made into carbon by carbonization that led to pore formation (pore width of 2.35 nm) on the cell surface. The average size of silver nanoparticles in the sample of SACF (silver nanoparticles adhered to mesoporous carbonized fungal cell) was 35 nm. Whereas mesoporous carbonized control fungal (CCF) cell was devoid of any particles on its surface. For structural characterizations of this adsorbent as well as to emerge its changes as a validation of arsenic adsorption, different biophysical methods such as FTIR, XRD, SEM, FESEM, TEM, BET surface area analysis and SERS analysis were followed. Batch mode experiments were performed to investigate the influence of As (V) concentrations, reaction time, pH of the solution and also the temperature of experiments on the efficiency of As (V) removal by adsorbents SACF & CCF. This arsenic-adsorbent interaction was proved to be endothermic in nature as well as the negative ΔG value indicated the spontaneity. SACF showed exceptional efficiency for the removal (>93%) of arsenic rather than CCF from an aqueous environment within a very short time of 3.5 h due to its porosity and the presence of the silver nanocrystals.

Bio-fabrication of silver nanoparticles using the leaf extract of an ancient herbal medicine, dandelion (Taraxacum officinale), evaluation of their antioxidant, anticancer potential, and antimicrobial activity against phytopathogens.

In recent years, the use of nanoparticle-based antimicrobials has been increased due to many advantages over conventional agrochemicals. This study investigates the utilization of common medicinal plant dandelion, Taraxacum officinale, for the synthesis of silver nanoparticles (TOL-AgNPs). AgNPs were evaluated for antimicrobial activity against two important phytopathogens, Xanthomonas axonopodis and Pseudomonas syringae. The morphology, size, and structure of TOL-AgNPs were characterized using UV-visible spectroscopy and X-ray diffraction (XRD). Fourier transform infrared spectroscopy (FT-IR) showed the presence of phytochemicals involved during synthesis of NPs. High-resolution transmission electron microscopy (HR-TEM) analysis shed light on the size of monodispersed spherical AgNPs ranging between 5 and 30nm, with an average particle size of about 15nm. The TOL-AgNPs (at 20μg/mL concentration) showed significant antibacterial activity with significant growth inhibition of phytopathogens X. axonopodis (22.0±0.84mm) and P. syringae (19.5±0.66mm). The synthesized AgNPs had higher antibacterial activity in comparison with commercial AgNPs. Synergistic assays with standard antibiotics revealed that nanoformulations with tetracycline showed better broad-spectrum efficiency to control phytopathogens. They also possessed significant antioxidant potential in terms of ABTS (IC50=45.6μg/mL), DPPH (IC50=56.1μg/mL), and NO (IC50=55.2μg/mL) free radical scavenging activity. The TOL-AgNPs showed high cytotoxic effect against human liver cancer cells (HepG2). Overall, dandelion-mediated AgNPs synthesis can represent a novel approach to develop effective antimicrobial and anticancer drugs with a cheap and eco-friendly nature.

Biogenic silver nanoparticles from Trichodesma indicum aqueous leaf extract against Mythimna separata and evaluation of its larvicidal efficacy

AbstractThe present exploration is focused on the bio-fabrication of silver nanoparticles (Ag NPs) usingTrichodesma indicumaqueous leaf extract as a reducing agent. The synthesized Ag NPs were productively characterized by UV-vis spectroscopy, XRD, and TEM studies. The photosynthesis of Ag NPs was done at room temperature for 24 h and at 60°C. The green synthesis of spherical-shaped Ag NPs bio-fabricated fromT. indicumwith a face centred cubic structure showed average particle sizes of 20–50 nm, which is inconsistent with the particle size calculated by the XRD Scherer equation and TEM analysis. We further explored the larvicidal efficacy of biosynthesized Ag NPs with leaf extracts ofT. indicumagainstMythimna separata. The results showed that Ag NPs (20–50 nm) ofT. indicumpossess good larvicidal activity againstM. separatawith an LC50of 500 ppm. Thus, we can advocate that Ag NPs of 20–50 nm size extracted fromT. indicummay be considered in the pest management programme ofM. separatain future.

Potential therapeutic activity of Phlogacanthus thyrsiformis Hardow (Mabb) flower extract and its biofabricated silver nanoparticles against chemically induced urolithiasis in male Wistar rats

Urolithiasis is a painful disorder in which stones are formed in the kidney, bladder or urethra. There are no proper therapeutic treatments available for kidney stones and people suffering from larger stones have to undergo surgery which has many side effects. A natural remedy with therapeutic effects that can dissipate and remove even the larger stones would eliminate the need of a surgery and the risks associated with it. The flowers of Phlogacanthus thyrsiformis used in culinary recipes in the north eastern India are also widely used as a folklore medicine for the treatment of kidney stones and liver disorders. The aim of this study was to evaluate the prophylactic and therapeutic activity of the aqueous extract of P. thyrsiformis flowers and its biofabricated silver nanoparticles against struvite urinary stones and calcium oxalate kidney stones. A kidney stone inhibition study was carried out on struvite stones grown in gel medium and calcium oxalate stones in rat models using an aqueous extract of P. thyrsiformis flowers and its biofabricated silver nanoparticles. The aqueous extract of P. thyrsiformis flowers and their biofabricated silver nanoparticles, obtained by a green synthetic method, were used to treat struvite urinary stones in vitro and calcium oxalate kidney stones in vivo. Struvite stones were grown in tubes by gel diffusion technique and were treated with varying concentrations of the extract and its nanoparticles. The size of the struvite stones was monitored for 96h using a travelling microscope. Calcium oxalate stones were induced in male Wistar rats by feeding ethylene glycol-ammonium chloride mixture for 14days. Both, prophylactic and therapeutic activities were evaluated by analyzing the urine, serum and histopathological parameters of the rats. The qualitative screening of water extract unveiled the presence of flavonoids as a major constituent. Both, the extract and the nanoparticles effectively reduced the size of struvite stones in vitro and eliminated calcium oxalate stones in Wistar rats in vivo. The potent therapeutic activity of both extract and silver nanoparticles was observed as compared to preventive activity. Anti-urolithiatic potency can be attributed to the presence of flavonoids.

Bio-fabricated silver nanoparticles preferentially targets Gram positive depending on cell surface charge.

Recently bio-inspired experimental processes for synthesis of nanoparticles are receiving significant attention in nanobiotechnology. Silver nanoparticles (Ag NPs) have been used very frequently in recent times to the wounds, burns and bacterial infections caused by drug-resistant microorganisms. Though, the antibacterial effects of Ag NPs on some multi drug-resistant bacteria specially against Gram positive bacteria has been established, but further investigation is needed to elicit its effectiveness against Gram negatives and to identify the probable mechanism of action. Thus, the present study was conducted to synthesize Ag NPs using Andrographis paniculata leaf extract and to investigate its antibacterial efficacy. After synthesis process the biosynthesized nanoparticles were purified and characterized with the help of various physical measurement techniques which raveled their purity, stability and small size range. The antimicrobial activity of Ag NPs was determined against both Gram-positive Enterococcus faecalis and Gram-negative Proteus vulgaris. Results showed comparatively higher antibacterial efficacy of Ag NPs against Gram positive Enterococcus faecalis strains. It was found that greater difference in zeta potential values between Gram positive bacteria and Ag NPs triggers better internalization of the particles. Thus the cell surface charge played vital role in cell killing which was confirmed by surface zeta potential study. Finally it may be concluded that green synthesized Ag NPs using Andrographis paniculata leaf extract can be very useful against both multi drug resistant Gram-positive and Gram-negative bacteria.

Swift Fabrication of Silver Nanoparticles Using Bougainvillea glabra: Potential Against the Japanese Encephalitis Vector, Culex tritaeniorhynchus Giles (Diptera: Culicidae)

Mosquitoes are the most critical group of insects in the context of public health, since they transmit key parasites and pathogens, causing millions of deaths annually. Culex tritaeniorhynchus is an important vector of Japanese encephalitis (JE) across urban and semi-urban areas of Asia. In this study, we bio-fabricated silver nanoparticles (Ag NP) using the leaf extract of Bougainvillea glabra as reducing and stabilizing agent. The synthesis of Ag NP was confirmed analyzing the excitation of surface Plasmon resonance using ultraviolet–visible (UV–vis) spectrophotometry. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed the clustered and irregular shapes of Ag NP. The presence of silver was determined by energy dispersive X-ray (EDX) spectroscopy. Fourier transform infrared (FTIR) spectroscopy analysis investigated the identity of secondary metabolites, which may act as Ag NP capping agents. The acute toxicity of B. glabra extract, synthesized Ag NP and a combined treatment testing blends of both mosquitocidals was evaluated against larvae and pupae of Cx. tritaeniorhynchus.B. glabra showed LC50 of 198.93 (larva I), 234.50 (II), 309.18 (III), 371.69 (IV) and 466.09 (pupa) µg/ml, Ag NP LC50 ranged from 7.77 (I) to 19.44 µg/ml (pupa). Combined treatments with B. glabra leaf extract plus 5.12.5 µg/ml of Ag NP lowered the botanical LC50 to 66.09 (I), 76.48 (II), 99.02 (III), 133.43 (IV) and 179.74 µg/ml (IV), respectively. The effectiveness of green-fabricated Ag NP against the JE vector was confirmed in adulticidal tests, as well as evaluating the impact of Ag NP on fecundity and longevity of adult mosquitoes. Lastly, the larvicidal effectiveness of Ag NP was confirmed in the field, treating sewage water bodies. Overall, this study suggests that the green-synthesized Ag NP fabricated using B. glabra can be considered a potential mosquito control device against the JE vector, C. tritaeniorhynchus in Asian regions.

Biofabricated silver nanoparticles as green catalyst in the degradation of different textile dyes

Biogenic silver nanoparticles (AgNPs) synthesized by Sterculia acuminata fruit extract was characterized by UV–vis spectroscopy, XRD, TEM, FTIR, PSA, and Zeta potential studies. Formation of AgNPs is initially confirmed by UV–vis spectroscopic studies with the characteristic band at 426nm. TEM and XRD reports revealed that AgNPs are highly crystalline and spherical in shape with average particle size of ∼10nm. PSA studies revealed that average particle size of AgNPs is 10.3nm which is in close agreement with TEM reports. FTIR studies indicated the presence of different functional groups on the surface of the AgNPs indicating the stability of AgNPs by capping of biomolecules onto the surface which is further supported by zeta potential studies with the negative zeta potential value of −39.2mV. Further catalytic efficiency synthesized AgNPs was evaluated for the reduction/degradation of various organic dyes such as 4-nitrophenol (4-NP), methylene blue (MB), methyl orange (MO), phenol red (PR) and direct blue 24 (DB24). It was found that degradation of MB and DB24 was faster than that of other dyes. This is the first report on degradation of organic dyes PR and DB24 using NaBH4 as reducing agent in the presence of catalytic amount of AgNPs.

Ecofriendly Synthesis of Silver Nanoparticles Using Ethno Medicinal Plant Leaf Extract (&lt;i&gt;Jasminum auriculatum&lt;/i&gt;) and their Antibacterial Properties

The present investigation, we describe a cost effective biofabrication of silver nanoparticles using jasminum auriculatum leaf extract. The aqueous leaf extract of jasminum auriculatum are used as reducing agent and capping agent in silver nanoparticles synthesis. The biofabricated silver nanoparticles were characterized by UV-Visible spectrophotometer, X-Ray Diffraction, FTIR spectra and SEM with EDX analysis. FTIR studies revealed that the functional group responsible for silver reduction were found to be jasminol and triterpinoid compounds present in leaf extract. XRD analysis showed that prepared silver nanoparticles are crystalline in nature with an average diameter of 15-20 nm. The prepared silver nanoparticles have been evaluated in vitro for antibacterial activities and found to have higher antibacterial activities.

Ecofriendly Synthesis of Silver Nanoparticles Using Ethno Medicinal Plant Leaf Extract (&lt;i&gt;Jasminum auriculatum&lt;/i&gt;) and their Antibacterial Properties

The present investigation, we describe a cost effective biofabrication of silver nanoparticles using jasminum auriculatum leaf extract. The aqueous leaf extract of jasminum auriculatum are used as reducing agent and capping agent in silver nanoparticles synthesis. The biofabricated silver nanoparticles were characterized by UV-Visible spectrophotometer, X-Ray Diffraction, FTIR spectra and SEM with EDX analysis. FTIR studies revealed that the functional group responsible for silver reduction were found to be jasminol and triterpinoid compounds present in leaf extract. XRD analysis showed that prepared silver nanoparticles are crystalline in nature with an average diameter of 15-20 nm. The prepared silver nanoparticles have been evaluated in vitro for antibacterial activities and found to have higher antibacterial activities.

Biofabrication, characterization and antibacterial efficacy of extracellular silver nanoparticles using novel fungal strain of Penicillium atramentosum KM

The biofabricated silver nanoparticles are extensively used in environmental, biotechnological and biomedical applications. The synthesis of SNPs has been carried out by using the filtrate extract of novel fungal strain Penicillium atramentosum KM. To undertake this study, P. atramentosum KM extract was exposed to silver nitrate and the obtained SNPs were thoroughly analyzed using physicochemical characterization tools such as UV–visible spectroscopy (UV–vis), Fourier transformation infrared (FTIR), X-ray diffraction (XRD) and transmission electron microscopy (TEM). As evident from the FTIR spectra plausibly the protein components of fungal extract caused the reduction of silver nitrate. The SNPs showed a characteristic UV–visible peak at 420nm with an average size of 5–25nm. The XRD record exhibited the characteristic peaks of 111, 200, 220 and 311 nanoparticles signifying that these nanoparticles were crystalline in nature. Parametric optimization showed maximum absorbance of 420nm at pH 7, 25°C with 3mM silver nitrate, concentration ratio of fungal extract and silver nitrate was 5:5 in 72h. The synthesized SNPs showed antimicrobial activity against bacterial strains.

Biofabricated silver nanoparticles act as a strong fungicide against Bipolaris sorokiniana causing spot blotch disease in wheat.

The present study is focused on the extracellular synthesis of silver nanoparticles (AgNPs) using culture supernatant of an agriculturally important bacterium, Serratia sp. BHU-S4 and demonstrates its effective application for the management of spot blotch disease in wheat. The biosynthesis of AgNPs by Serratia sp. BHU-S4 (denoted as bsAgNPs) was monitored by UV–visible spectrum that showed the surface plasmon resonance (SPR) peak at 410 nm, an important characteristic of AgNPs. Furthermore, the structural, morphological, elemental, functional and thermal characterization of bsAgNPs was carried out using the X-ray diffraction (XRD), electron and atomic microscopies, energy dispersive X-ray (EDAX) spectrometer, FTIR spectroscopy and thermogravimetric analyzer (TGA), respectively. The bsAgNPs were spherical in shape with size range of ∼10 to 20 nm. The XRD and EDAX analysis confirmed successful biosynthesis and crystalline nature of AgNPs. The bsAgNPs exhibited strong antifungal activity against Bipolaris sorokiniana, the spot blotch pathogen of wheat. Interestingly, 2, 4 and 10 µg/ml concentrations of bsAgNPs accounted for complete inhibition of conidial germination, whereas in the absence of bsAgNPs, conidial germination was 100%. A detached leaf bioassay revealed prominent conidial germination on wheat leaves infected with B. sorokiniana conidial suspension alone, while the germination of conidia was totally inhibited when the leaves were treated with bsAgNPs. The results were further authenticated under green house conditions, where application of bsAgNPs significantly reduced B. sorokiniana infection in wheat plants. Histochemical staining revealed a significant role of bsAgNPs treatment in inducing lignin deposition in vascular bundles. In summary, our findings represent the efficient application of bsAgNPs in plant disease management, indicating the exciting possibilities of nanofungicide employing agriculturally important bacteria.

Biofabrication of Silver Nanoparticles by Opuntia ficus-indica: In vitro Antibacterial Activity and Study of the Mechanism Involved in the Synthesis

We report Opuntia ficus-indica mediated synthesis of colloidal silver nanoparticles. Detection and characterization of nanoparticles were carried out by UV-Vis- and Fourier Transform Infra Red Spectroscopy, Scanning Electron Microscopy and X-ray Diffraction analysis respectively. The aim of the present study was synthesis of silver nanoparticles, assessment of their antibacterial activity, and study of possible mechanism involved. The silver nanoparticles in combination with commercially available antibiotics showed a remarkable antibacterial activity. Some of the commercially available antibiotics in combination with silver nanoparticles showed remarkable activity. However, the maximum activity was demonstrated by Ampicillin followed by Streptomycin and Vancomycin. On the basis of the information obtained in this work, two-step mechanism has been proposed as bioreduction and formation of an intermediate complex leading to formation of capped nanoparticles.