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The biosynthesis of silver nanoparticles (AgNPs) using an aqueous extract of an agroindustrial residue of the tequila industry [i.e. leaves of Agave tequilana Weber var. azul (AT)], and silver nitrate or silver acetate as precursor salts is reported. The presence of AgNPs was confirmed by color change, scanning electron microscopy, ultraviolet visible spectroscopy and X-ray diffraction. AgNPs were tested against clinically important bacteria. The effect of extract concentration and the reaction temperature was investigated. Results revealed that, the concentration of AgNPs increases as temperature and extract concentration increase. AgNPs were found to be mainly spherical shaped and showed antibacterial activity against Staphylococcus aureus , Escherichia coli and Pseudomonas aeruginosa . Results demonstrate the possibility of using a natural extract obtained from an abundant agroindustrial residue for the sustainable synthesis of AgNPs. [ABSTRACT FROM AUTHOR]

We have demonstrated a one pot green protocol for the synthesis of highly monodispersed silver nanoparticles using leaves of Salvadora persica plant. When the leaf extract of Salvadora persica plant reacted with silver nitrate (AgNO 3 ) solution it resulted in the synthesis of highly monodispersed silver nanoparticles with an average size of 3 nm. These nanoparticles were then completely characterized by UV–Visible spectroscopy, Transmission Electron Microscopy, Energy Dispersive Analysis of X-Rays, X-ray diffraction analysis and Fourier Transform Infrared analysis. [ABSTRACT FROM AUTHOR]

Green synthesis of silver nanoparticles (AgNPs) has gained widespread interest as the alternative method to use natural, non-toxic substances to facilitate the formation of AgNPs. This work reported on the alternative source of reducing and stabilizing agents from tissue extract of weaver ant ( Oecophylla smaragdina ) larvae. The formation of AgNPs in the reaction containing silver nitrate, the tissue extract, and glucose at 60 °C was indicated by the surface plasmon resonance at 428 nm. Transmission electron microscopy images revealed spherical AgNPs with the average diameter of 67.4 nm. The synthesized AgNPs exhibited potent antibacterial activity against both Staphylococcus aureus and Escherichia coli with the minimum bactericidal concentrations equally at 16 μg/mL. [ABSTRACT FROM AUTHOR]

Biological entity is gaining significant prominence in green synthesis of silver nanoparticles as a result of their potential applications in nanomedicine and material engineering. Herein, we have reported the green synthesis of Artocarpus altilis silver nanoparticles (BAgNPs) using aqueous leaf extract of Artocarpus altilis . Synthesized colloidal BAgNPs were confirmed spectrophotometrically at 432 nm and the various reaction conditions were optimized. The SEM, TEM and DLS analysis confirmed that the average particle size of BAgNPs was 34 nm, 38 nm, and 162.3 d.nm, respectively. Nature and presence of silver were confirmed by XRD and EDX. Further, FT-IR spectra of the synthesized BAgNPs authorized the presence of phyto constituents as capping agent. The BAgNPs showed moderate antimicrobial and antioxidant activities. The present study revealed the safer use of eco-friendly green synthesized BAgNPs in near future in the field of biomedicine, water treatment or purification, and nanobiotechnology. [ABSTRACT FROM AUTHOR]

A medicinally important Sida cordifolia leaf extract has been used for biogenic synthesis of silver nanoparticles (AgNPs) in presence of sunlight and demonstrated enhanced biological activities. AgNPs were characterized using UV–vis spectroscopy, Fourier Transform Infrared spectroscopy (FTIR), transmission electron microscope (TEM), scanning electron microscope (SEM), Zeta potential and energy dispersive X-ray analysis (EDAX). Interestingly, bio-functionalized AgNPs displayed higher antioxidant activity in terms of reducing power on ferric ion (1.83 AU) and phosphomolybdate (2127 Ascorbic acid Equivalent Antioxidant Activity) and radical scavenging activity against superoxide (IC50 value 46.25 µg/ml) and DPPH radicals (IC50 value 50.12 µg/ml) compared to the standard. AgNPs has also exhibited cytotoxic effect with IC 50 value of 204 and 129 µg/ml against EAC and HT-29 cancer cell lines, respectively which indicates the AgNPs are effective than that of commercially available drug. Thus, enhanced biological activities have been achieved by incorporating AgNPs with biologically active molecules. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) were synthesized in low cost skim natural rubber latex by adding silver nitrate as a source of silver ions. Left-over ammonia in latex was believed to form a complex with silver ions before reacting with the reducing agents which were glucose and other organic compounds in latex. Moreover, protein in latex could also control the growth of the particles by acting as a stabilizing agent. Many factors, which include ammonia content, d -glucose content and BSA protein content, were studied to clarify their effects in the synthesis. The emergence of AgNPs was checked with UV–visible spectrometer and electrical conductivity meter. Transmission electron microscope (TEM) was applied to study the particle morphology. The results showed that UV absorbance (ABS) and conductivity of the reacting suspension increased when ammonia content and d -glucose content increased, implying an increasing number or growth of particles. In contrast, ABS and conductivity decreased with increasing BSA content, showing that smaller particles were formed. The TEM images confirmed that the size of AgNPs in the none-added sample was 6–26 nm. The synthesized AgNPs could inhibit the growth of Escherichia coli and Staphylococcus aureus . [ABSTRACT FROM AUTHOR]

The present study was aimed at the biosynthesis of silver nanoparticles (AgNPs) using aqueous extract of Clerodendron serratum (AECS) leaves and testing their potential in vitro anticancer activity using Ehrlich ascites carcinoma (EAC) cell lines. This medicinal plant was found to be rich in polyphenol glycosides and two compounds-baicalein and quercetin 3-O-β- d -glucoside was isolated from the extract. The biologically synthesized AgNPs were characterized using UV–vis spectrophotometry, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and X-ray Diffraction (XRD). The antiproliferative ability of the AgNPs was evaluated using cell viability and MTT assays and the results showed that biosynthesized AgNPs possesses significant in vitro antiproliferative activity. [ABSTRACT FROM AUTHOR]

This study reports the green synthesis of silver chloride nanoparticles (AgClNPs) and silver nanoparticles (AgNPs) from aqueous corn husk extracts. The effect of changes in the extract volume and the pH on the green synthesis of these nanoparticles is investigated. The formation of AgClNPs and AgNPs was monitored using a UV–vis spectrophotometer. XRD was used to characterize AgClNPs and AgNPs, and it was determined that, by varying the pH, it is possible to control the synthesis of both nanoparticles in a single pure phase. FTIR showed that the phytochemicals from the corn husks are responsible for the reduction and stabilization of the resulting particles. TEM analysis showed the formation of crystals with average sizes of 20 nm, and the SEM-EDS analysis validated the presence of silver. The synthesized nanoparticles had antibacterial activity against Escherichia coli and Staphylococcus aureus. [ABSTRACT FROM AUTHOR]

• The antimicrobial properties of AgNPs are affected by their size. • The viscosity of the reaction system and size of crystal growth space affect AgNPs size. • Preparing AgNPs by using N -maleoyl chitosan and montmorillonite. • Higher antibacterial ability and lower cytotoxicity. The antimicrobial properties of silver nanoparticles (AgNPs) are significantly affected by their size. In our previous study, we synthesized low-toxicity AgNPs using chitosan derivatives. As chemical reductants and stabilizers were not used in the preparation process, the toxicity of the products was very low. However, the size of the as-obtained nanoparticles was relatively large (100–150 nm). In this study, we used N -maleoyl chitosan and montmorillonite to prepare small-sized green AgNPs and investigated the effect of the reaction system viscosity and crystal growth space on the formation of small-sized nanoparticles. We found that increasing the viscosity of the reaction system or controlling the crystal growth space was conducive to the green preparation of small-sized AgNPs. The prepared AgNPs had higher antibacterial ability and lower cytotoxicity. To the best of our knowledge, this is the first time that AgNPs with such a small size (less than 5 nm) have been prepared using a simple and completely green method. [ABSTRACT FROM AUTHOR]

The present study focuses on the green synthesis of silver nanoparticles using aqueous extract of Tephrosia tinctoria (TT). This medicinal plant was rich in phenol and flavonoids groups of compounds. They reduced the silver nitrate into silver nanoparticle (AgNPs) and which were characterized using UV–vis spectrophotometry, X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-Ray (EDAX) patterns and FT-IR. The XRD analysis illustrated that the silver nanoparticles were crystalline in nature. The SEM and TEM analyses revealed that the synthesized silver nanoparticles were spherical in shape and the particle size was found to be less than 100 nm. The antidiabetic ability of the AgNPs was tested and the results showed significant free radical scavenging ability, inhibition of carbohydrate digestive enzymes (α-Glucosidase and α-Amylase) and enhancement of Glucose uptake rate. The FT-IR result revealed that the presence of various functional groups around AgNPs. [ABSTRACT FROM AUTHOR]

In the recent decades, development of green nanotechnology is generating interest of researchers toward ecofriendly biosynthesis of nanoparticles, because of its incredible applications in all fields of science. In this study, to explore the novel approaches for the biosynthesis of silver nanoparticles, the seaweed Enteromorpha flexuosa (wulfen) J. Agardh extract was mixed with silver nitrate to synthesize silver nanoparticles. The reduced silver nanoparticles were characterized by UV–vis spectrophotometer, energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The in vitro antimicrobial activity of the synthesized nanoparticles of E. flexuosa exhibited high antibacterial activity against Gram-positive bacteria and low activity against the Gram-negative organisms. The algae materials mediated synthesis of silver nanoparticles have comparatively rapid, less expensive and wide applications to antimicrobial therapy in modern medicine. [ABSTRACT FROM AUTHOR]

In this study, the fabrication of colloidal silver nanoparticles (AgNPs) by cost-effective and environmental friendly method has been demonstrated. Rhodomyrtus tomentosa acetone extract (RAE) was used for the first as combined reducing and capping reagent time for AgNPs synthesis. The AgNPs were characterized by UV–visible spectroscopy, FTIR, XRD, zeta potential and DLS. AgNPs demonstrated profound antibacterial activity against Staphylococcus aureus with MIC and MBC ranging between 3.1–6.2 and 6.2–50 µg/ml, respectively. The outcomes of this study indicated that the synthesized AgNPs could be applied as an effective antimicrobial agent. [ABSTRACT FROM AUTHOR]

[Display omitted] • AgNPs were facile synthesized from Glochidion candolleanum leaf (GCL) extract. • FT-IR, FE-SEM, and TEM analyses confirmed the properties of AgNPs. • GCL·AgNPs exhibited antimicrobial activity against G+ve and G−ve bacteria. • GC–MS revealed the presence of antimicrobial phytochemicals in GCL extract. In the present study, Glochidion candolleanum (Wight & Arn.) Chakrab. & M. Gangop. leaf (GCL)-ethyl acetate extract was used for the phytosynthesis of silver nanoparticles (AgNPs) and subjected to antibacterial assay with G+ve and G−ve bacteria. The GCL·AgNPs synthesized were characterized through various spectroscopic and microscopic analyses, while the phytochemical compounds was analyzed by GC–MS. The discrete GCL·AgNPs formed were micron-scale range. TEM images of AgNPs reveal that nanoparticles were spherical and ellipsoidal in shape, dispersed uniformly and capped with secondary material of ≈10 nm thickness. A maximum inhibition zone of 12.2 mm diameter was observed against Salmonella enterica followed by 11.8 mm diameter against Pseudomonas aeruginosa. GC–MS analysis revealed the occurrence of bioactive phytocompounds in GCL extract, hexamethylcyclotrisiloxane, 2,4,6-cycloheptatrien, benzenepropanoic acid, 2-ethylacridine, benzo[h]quinoline, methyltris(trimethylsiloxy)silane and 5-methyl-2-phenylindolizine. The findings suggest that GCL could be used for developing antibacterial AgNPs against pathogenic bacteria. [ABSTRACT FROM AUTHOR]

In this investigation, we report the formation of new 3-D aggregates consisting of Ag-Au nanoparticles obtained in aqueous solution by a facile method using Aloysia triphylla plant extract as a reducing and stabilizing agent. SEM and EDS analysis reveal that the dimensions of 3-D arrays are estimated to be about 2.5 µm wide, 0.5 µm thick, and 2 µm long. The 3-D geometric aggregates have strong microstructures that are similar to those of ordinary crystalline materials. The microstructures are close-packed with straight edges and facets but do not have grain boundaries. HRTEM images indicate that the 3-D arrays are a consequence of the nanoparticles aggregation inside an organic matrix and the presence of Au forming the BNPs. [ABSTRACT FROM AUTHOR]

Abstract: The present investigation deals with the synthesis of silver nanoparticles (AgNPs) by green synthesis that has advantages over conventional methods involving chemical agents associated with environmental toxicity. Green synthesis method involves the use of Syzygium aromaticum extract in the universal solvent namely water. The reaction process was simple and convenient to handle, and was monitored using ultraviolet–visible spectroscopy (UV–vis). The results were promising and rapid in the production of silver nanoparticle with a surface plasmon resonance occurring at 430nm. The formed nanoparticles ranged in dimension between 20 and 149nm which was almost spherical in shape. EDAX confirmed that the formed nanoparticles are silver as the optical absorption peak was observed approximately at 3keV, which is typical for the absorption of metallic silver nanocrystallites. [Copyright &y& Elsevier]

Abstract: The role of pH in the green synthesis of silver nanoparticles (AgNPs) is investigated. For the reduction synthesis of AgNPs we use silver nitrate, glucose, sodium hydroxide and starch respectively to serve as precursor, reducing agent, accelerator and stabilizer. The effect of NaOH addition on the nature of AgNPs is systematically studied. Two reaction pathways are proposed to explain the formation of AgNPs, keeping in view the pH changes that occur on addition of different amounts of NaOH. The aqueous sol of AgNPs prepared at different pH values display different surface plasmon resonance (SPR) behavior. This is explained in terms of size and size distribution of AgNPs. [Copyright &y& Elsevier]

• A novel green synthesis method is employed for the synthesis of copper nanoparticles. • The average size of the synthesized Cu nanoparticles is in the range of 5–25 nm. • The obtained nanoparticles have shown good antibacterial activity against gram-positive and gram-negative bacteria. In the present report, for the first time aqueous extract of Curcuma longa powder is used for the synthesis of Copper nanoparticles (Cu NPs) using a simple and cost effective method. Morphology, size, crystallinity, composition and microstructure of the synthesized Cu Nps are studied. Size of the particles are in the range of 5–20 nm. In addition to the above, antibacterial activity of the obtained Cu NPs is tested for both gram-positive and gram-negative microorganisms. Zone of inhibition of Cu NPs for gram positive bacteria is more compared to gram negative bacteria. The current work on green synthesis of metallic nanoparticles can be considered as an alternative method to avoid the usage of hazardous compounds and bitter reaction conditions in the production of metal nanoparticles. The obtained Cu NPs with their distinctive structural properties and effective biological effects can be used in applications viz. antimicrobial, antifungal, anticancer activity. [ABSTRACT FROM AUTHOR]