Spherical Silver Research Articles

Mathematical modelling of seed-mediated size-specific growth of spherical silver nanoparticles using Azadirachta indica leaf extract

ABSTRACT Spherical silver nanoparticles of required size were synthesized employing a seed-mediated approach using leaf extract of Azadirachta indica. Reaction pH was used to manipulate the rate of reduction of the precursor salt for achieving a fast rate of reaction needed during the synthesis of silver nanoparticles seeds and a slower rate of reaction needed for controlled growth and inhibition of secondary nucleation. A mathematical model was developed for staggered growth of silver nanoparticles using a multi-step growth approach. The developed model was used to predict the size of silver nanoparticles after various growth steps and was compared with the experimentally achieved results. Transmission electron microscope images were used for the determination of the size of the synthesized silver nanoparticles. The mathematical model appears to be a promising tool in enabling real-life application of green synthesized silver nanoparticles.

Biosynthesis of silver nanoparticles using the leaf and stem bark of Diospyros discolor Willd. (Ebenaceae)

The synthesis of nanoparticles using parts of plants is extremely attractive because it is environmentally friendly. This study examined the suitability of the leaf and stem bark extracts of the plant Diospyros discolor for the synthesis of silver nanoparticles. The reaction could be monitored by visual examination, because the formation of silver nanoparticles was accompanied by a color change of the solution. The characterization of silver nanoparticles was performed using UV–visible, particle size analyzer, and transmission electron microscopy analyses. We observed that the process of nucleation of the silver nanoparticles required several hours. The biosynthesis of silver nanoparticles using the stem bark extract was faster than that using the leaf extract. In addition, the volume ratio of the extracts and AgNO3 solutions greatly affected the yield of silver nanoparticles. This effect was more significant in the case of the leaf extract. This biosynthesis successfully afforded spherical silver nanoparticles of about 30 nm in diameter, which were relatively stable on the basis of zeta potential measurements.

Effect of Hybrid Particles of Nano-Micron Sizes on Electrical Transport of Silver-Epoxy Composites

Electrically Conductive Adhesive’s (ECAs) mainly consist of a polymer as matrix and binder to filler as conductor. The performance of electrical properties in ECAs strongly depends on the concentration (volume fraction) of the metal filler, morphology of the filler, filler distribution within the polymer matrix, the interaction between filler surface, and the contact resistance between adjacent particles. In this work, the characteristics of electrical transport of ECA's systems on Ag-Epoxy composites are containing either micro or nano fillers are studied by the electric static network theory using FEM. The hybrid system will be formed for considering influence electrical transport properties. The spherical Silver (Ag) used 80 nm and 2 μm in diameter in this study. Two particles chain forming electrically transport with some number of particles and reach a conductivity value of ECA's. The result indicated that nano size silver usually lower its conductivity than micron size. During simulation, it has been shown the correlation between nano and micron size demonstrated a increasing in the electrical transport when the hybrid system performed.

Antibacterial effect of cotton fabric treated with silver nanoparticles of different sizes and shapes

Stable silver Nanoparticles in solutions of sodium-carboxymethylcellulose (Na-CMC) were synthesized, and their structure and physico-chemical properties were studied. The form and sizes of silver nanoparticles formed in solutions of CMC and cotton fabrics were studied using UV-VIS spectroscopy, atomic force microscopy and transmission electron microscopy methods. It was found that the silver nitrate concentration increase in sodium carboxymethylcellulose solutions, as well as photoirradiation of the hydrogel lead to the changes of the silver nanoparticles size and shape. Investigations have shown that spherical silver nanoparticles with sizes of 5-35nm and content of 0.0086 mass% in cotton fabrics possess high bactericidal activity. Stabilization of silver nanoparticles has preserved bactericidal and bacteriostatic activities during the washing of cotton fabrics and textiles on their base.

Green Synthesis of Silver Nanoparticles by Low-Energy Wet Bead Milling of Metal Spheres.

A low-energy, magnetically-driven milling technique for the synthesis of silver nanoparticles is proposed, where the grinding medium and the metal precursor consisting of silver spheres have the same shape and size, belonging to a millimetric scale. The process is carried out at room temperature in aqueous solvent, where different types of capping agents have been dissolved to damp particle agglomeration. The particle diameters, determined by dynamic light scattering and transmission electron microscopy, have been compared with those typical of conventional wet-chemical bottom-up synthesis processes. The use of milling spheres and metal precursor of the same initial shape and size allows to overcome some drawbacks and limitations distinctive of conventional bead-milling equipment, generally requiring complex operations of separation and recovery of milling media. The milling bead/nanoparticle diameter ratio obtained by this approach is higher than that typical of most previous wet bead milling techniques. The method described here represents a simple, one-pot, cost-effective, and eco-friendly process for the synthesis of metal nanoparticles starting from a bulky solid.

Computational nanoplasmonics in the quasistatic limit for biosensing applications.

The phenomenon of localized surface plasmon resonance (LSPR) provides high sensitivity in detecting biomolecules through shifts in resonance frequency when a target is present. Computational studies in this field have used the full Maxwell equations with simplified models of a sensor-analyte system, or they neglected the analyte altogether. In the long-wavelength limit, one can simplify the theory via an electrostatics approximation while adding geometrical detail in the sensor and analytes (at moderate computational cost). This work uses the latter approach, expanding the open-source PyGBe code to compute the extinction cross section of metallic nanoparticles in the presence of any target for sensing. The target molecule is represented by a surface mesh, based on its crystal structure. PyGBe is research software for continuum electrostatics, written in python with computationally expensive parts accelerated on GPU hardware, via PyCUDA. It is also accelerated algorithmically via a treecode that offers O(NlogN) computational complexity. These features allow PyGBe to handle problems with half a million boundary elements or more. In this work, we demonstrate the suitability of PyGBe, extended to compute LSPR response in the electrostatic limit, for biosensing applications. Using a model problem consisting of an isolated silver nanosphere in an electric field, our results show grid convergence as 1/N, and accurate computation of the extinction cross section as a function of wavelength (compared with an analytical solution). For a model of a sensor-analyte system, consisting of a spherical silver nanoparticle and a set of bovine serum albumin (BSA) proteins, our results again obtain grid convergence as 1/N (with respect to the Richardson extrapolated value). Computing the LSPR response as a function of wavelength in the presence of BSA proteins captures a redshift of 0.5 nm in the resonance frequency due to the presence of the analytes at 1-nm distance. The final result is a sensitivity study of the biosensor model, obtaining the shift in resonance frequency for various distances between the proteins and the nanoparticle. All results in this paper are fully reproducible, and we have deposited in archival data repositories all the materials needed to run the computations again and recreate the figures. PyGBe is open source under a permissive license and openly developed. Documentation is available at http://pygbe.github.io/pygbe/docs/.

Tunability of Surface Plasmon Resonance Peaks in CsI:Ag Films by Growth Conditions

The manuscript reports the optical, structural, and morphological properties of thin films of CsI:Ag composites fabricated under various conditions by thermal evaporation method on glass substrates. The absorption spectra of these films show strong surface plasmon resonance (SPR) absorption peak/s. In samples with spherical silver nanoparticles, position of SPR peaks revealed red shift that was due to the increase the particle size of silver. Also, appearance of a new SPR peak was detected towards higher wavelengths due to the proximity effect, i.e., due to decrease in the interparticle distance between the silver nanoparticles. In contrast, the thin films with silver nanorods exhibited typical two SPR peaks assigned to higher and lower frequencies of visible spectrum. The aspect ratio of the nanorods showed an increasing trend with increase in film thickness. Results of this manuscript show how to achieve tunability of SPR peaks by varying the growth condition and film thickness.

Temperature assisted reorganization of silver nanoparticles in free-standing, flexible chitosan functionalized reduced graphene oxide thick films: A potential SERS probe for folic acid sensing

Chitosan and silver functionalized free standing reduced graphene oxide (rGO) films were prepared using simple soak and dry strategy. Redistribution of silver aggregates on chitosan functionalized rGO films were observed by thermally annealing these films at 450 °C, in an inert atmosphere. The re-organization / redistribution of silver aggregates in the rGO films were studied using in-situ Raman scattering signals. The redistribution of silver particles occurs through melting of micron sized silver aggregates during annealing. The rearrangement of the micro-sized silver aggregates to spherical silver nanoparticle on chitosan functionalized rGO film, as a result of temperature was assisted through factors such as graphene surface ripple rearrangement and the denaturation of rGO surface interacting chitosan chains. These free-standing films with redistributed silver nanoparticles showed excellent surface enhanced Raman scattering (SERS) effect with enhanced Raman signals for folic acid sensing, showcasing its potentiality to be utilized as flexible SERS based sensors.

Green Synthesis of Silver Nanoparticles Using Hibiscus rosa-sinensis Leaf Extract

Background: Owing to their remarkable chemical, physical and biological properties, silver nanoparticles have been widely used in water purification, electronics, bio-sensing, clothing, food industry, paint and medical devices. Various approaches, such as using harsh reducing and stabilising agents for reverse micelle and thermal decomposition, were proposed for silver nanoparticle production. However, these methods are not eco-friendly. Thus, the aim of this paper is to synthesise silver nanoparticles through a cost-effective and environmentally friendly approach. Materials and Methods: A green approach was presented for the synthesis of silver nanoparticles. This approach involved the treatment of silver nitrate and hibiscus leaf extract, which acts as reducing and capping agent. The synthesis was performed at room temperature. The resulting silver nanoparticles were characterised by scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution TEM (HRTEM) and Fourier transform infrared (FTIR) spectroscopy. Results: Spherical, rod-like, hexagonal and triangular silver nanoparticles were obtained through the proposed synthesis method. The crystalline nature of each nanoparticle was revealed by XRD and selected area electron diffraction (SAED). The average spherical size of the silver nanoparticles produced in this route was 44.3 nm. The obtained FTIR band at 1622 cm-1 corresponded to the C=O stretch in the amine I group, which is commonly found in protein. Thus, the protein was believed to serve as capping agent that was responsible for the stabilisation of silver nanoparticles. Conclusion: In conclusion, silver nanoparticles had been successfully synthesised using hibiscus leaf extract and a plausible formation mechanism of silver nanoparticles was proposed.

Size controlled synthesis of well-distributed nano-silver on hydroxyapatite using alkanolamine compounds

A well-distributed nano-silver hydroxyapatite composite has been successfully prepared by a one-pot synthesis method. Hydroxyapatite was separately synthesized by a sol-gel method, then impregnated with silver nanoparticles with the mediation of Uncaria gambir Roxb. leaf extract in the presence of three kinds of alkanolamine compound; monoethanolamine (MEA), diethanolamine (DEA), and triethanolamine (TEA) as capping agents. The effect of different capping agents on the properties of the silver nanoparticles and the nano-silver hydroxyapatite composite were studied. UV–visible spectrophotometer analysis exhibited absorbance peaks at 402–439 nm which specifically corresponds to spherical silver nanoparticles. Higher optical absorbance was observed in TEA-capped silver nanoparticles, than in DEA and MEA-capped ones. X-ray diffraction (XRD) analysis showed a highly crystalline hexagonal structure for hydroxyapatite and no detected metallic silver. However, the presence of 1.65% silver was confirmed by energy dispersive x-ray (EDX) spectroscopy analysis. Transmission electron microscopy (TEM) analysis revealed spherical silver nanoparticles with a size range of 2–62 nm (smallest mean diameter of 2 nm) adhered to the hydroxyapatite surface. The TEA capped impregnated silver nanoparticles were the smallest, corresponding to the best capping performance, followed by those capped by DEA and MEA. Small-sized nanoparticles on hydroxyapatite are beneficial for highly antibacterial bone implants.

Fabrication of Interconnected Plasmonic Spherical Silver Nanoparticles with Enhanced Localized Surface Plasmon Resonance (LSPR) Peaks Using Quince Leaf Extract Solution.

Interconnected spherical metallic silver nanoparticles (Ag NPs) were synthesized in the current study using a green chemistry method. The reduction of silver ions to Ag NPs was carried out with low-cost and eco-friendly quince leaves. For the first time, it was confirmed that the extract solution of quince leaves could be used to perform green production of Ag NPs. Fourier transform infrared spectroscopy (FTIR) was conducted to identify the potential biomolecules that were involved in the Ag NPs. The results depicted that the biosynthesis of Ag NPs through the extract solution of quince leaf was a low-cost, clean, and safe method, which did not make use of any contaminated element and hence, had no undesirable effects. The majority of the peaks in the FTIR spectrum of quince leaf extracts also emerged in the FTIR spectrum of Ag NPs but they were found to be of less severe intensity. The silver ion reduction was elaborated in detail on the basis of the FTIR outcomes. In addition, through X-ray diffraction (XRD) analysis, the Ag NPs were also confirmed to be crystalline in type, owing to the appearance of distinct peaks related to the Ag NPs. The creation of Ag NPs was furthermore confirmed by using absorption spectrum, in which a localized surface plasmon resonance (LSPR) peak at 480 nm was observed. The LSPR peak achieved in the present work was found to be of great interest compared to those reported in literature. Field emission scanning electron microscopy (FESEM) images were used to provide the morphology and grain size of Ag NPs. It was shown from the FESEM images that the Ag NPs had interconnected spherical morphology.

Electrocatalytic Reduction of Hydrogen Peroxide and Its Non-Enzymatic Electrochemical Detection Using Silver Nanoparticles Anchored on Reduced Graphene Oxide.

Silver-reduced graphene oxide (Ag-rGO) nanohybrid was synthesized by applying a slight modification to the Turkevich method using trisodium citrate as a reducing and stabilizing agent to catalyze the non-enzymatic electrochemical detection of hydrogen peroxide (H₂O₂). Spherical silver nanoparticles (AgNPs) with an average particle size of 2.2 nm surfaced on reduced graphene oxide (rGO) sheets. Cyclic voltammograms (CV) obtained from glassy carbon (GC) electrode coated with Ag-rGO nanohybrid (4 mM) exhibited a peak at an overpotential of -0.52 V, with a larger faradaic current for the reduction of H₂O₂. Using the modified electrode for the linear sweep voltammetry (LSV) detection of H₂O₂, the detection limit and sensitivity were determined to be 4.8 μM (S/N ═ 3) and 0.0262 μA μM-1, respectively. The sensor appeared selective and stable towards H₂O₂ in the presence of possible interference, and it also demonstrated good recoveries of H₂O₂ concentration in real water samples.

New insights of the bacterial response to exposure of differently sized silver nanomaterials

The release of silver nanomaterials (AgNMs) from extensive use poses potential risks to human health and ecological environments. Although previous studies have reported the negative effects of AgNMs on various microorganisms, little is known about the response of bacteria under the exposure of AgNMs at the cellular level. Here, we report the multiple responses of Pseudomonas aeruginosa PAO1 (PAO1) under the exposure of two types of AgNMs, including spherical silver nanoparticles (AgNPs) and fibrous silver nanorods (AgNRs), by physiological experiments, microscopy, synchrotron-based X-ray Absorption Spectroscopy (XAS), flow cytometry and genome-wide RNA sequencing. Our results demonstrated that the exposure to both types of AgNMs could inhibit the growth of PAO1, accompanied by the overproduction of oxidative stress and inducing cell membrane damage. Transmission electron microscopy revealed the roughened cell membrane under both AgNMs treatment. In addition, both AgNMs repressed the expression of quorum sensing and metal efflux-related genes in PAO1, but stimulated denitrification, glycerol and amino acid metabolisms, SOS response and pyocin overproduction of PAO1. Compared to AgNRs, AgNPs exposure showed a much lower threshold concentration to trigger the inhibitory effect and induced greater transcriptional responses of PAO1. This study suggested that AgNMs could cause multiple effects on the proliferation, metabolism, virulence and pathogenesis of PAO1, which might further affect the corresponding environmental microbial communities. Overall, our findings offer insights into the interactions between AgNMs and bacteria at the molecular level.

Efficient and environmental-friendly perovskite solar cells via embedding plasmonic nanoparticles: an optical simulation study on realistic device architectures.

Solution-processed, lead halide-based perovskite solar cells have recently overcome important challenges, offering low-cost and high solar power conversion efficiencies. However, they still undergo unoptimized light collection due mainly to the thin (∼350 nm) polycrystalline absorber layers. Moreover, their high toxicity (due to the presence of lead in perovskite crystalline structures) makes it necessary that the thickness of the absorber layers to be further reduced. Here we address these issues via embedding spherical plasmonic nanoparticles of various sizes, composition, concentrations, and vertical positions, in realistic halide-based perovskite solar cells. We theoretically show that plasmon-enhanced near-field effects and scattering leads to a device photocurrent enhancement up to ∼7.3% when silver spheres are embedded inside the perovskite layer. An even further enhancement, up to ∼12%, is achieved with the combination of silver spheres in perovskite and aluminum spheres inside the hole transporting layer (PEDOT:PSS). The proper involvement of nanoparticles allows the employment of much thinner perovskite layers (up to 150 nm), reducing thus significantly the toxicity. Providing the requirements related to the design parameters of nanoparticles, our study establishes guidelines for a future development of highly-efficient, environmentally friendly and low-cost plasmonic perovskite solar cells.

Characterization of Cellulose/Silver Nanocomposites Prepared by Vegetable Oil-Based Microemulsion Method and Their Catalytic Performance to 4-Nitrophenol Reduction

In this work, Cellulose/silver nanocomposites were synthesized through a double vegetable oil-based microemulsion method. Ionic liquid 1-ethyl-3-methylimidazolium acetate ([Emim]Ac) or water was used as the polar phase to prepare [Emim]Ac (water) /Triton X-100 + n-butanol/castor oil microemulsions, respectively. The structure of the microemulsions was investigated by the pseudo-ternary phase diagrams and dynamic light scanning data. The microstructure, morphological characteristics, size, thermal stability, and catalytic performance of the as-prepared cellulose/silver nanocomposites were characterized through X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy/energy dispersive X-ray spectroscopy, thermogravimetric analysis, and UV–Visible spectrophotometry. Results revealed that the spherical silver nanoparticles (Ag NPs) dispersed homogeneously on the surface of cellulose regenerated from ionic liquid, and the average size of Ag NPs in the nanocomposites could be adjusted by controlling the AgNO3 concentration and the molar ratio of total polar phase to surfactant. The catalytic activity of cellulose/silver nanocomposites were examined by reducing 4-Nitrophenol to 4-Aminophenol and they displayed much higher activities than the unsupported Ag NPs. This approach is effective for the production of cellulose-supported metal nanoparticles, which offers promise in heterogeneous catalysis.

Novel green synthesis of silver nanoparticles using clammy cherry (Cordia obliqua Willd) fruit extract and investigation on its catalytic and antimicrobial properties

In this study, highly monodispersed, exceptionally stable, spherical silver nanoparticles (AgNPs) were successfully synthesized by the microwave assisted rapid and cost-effective green method. Aqueous extract of clammy cherry (Cordia obliqua Willd) fruit was used as the green reductant, and capping agent for the synthesis of AgNPs and the effect of different synthesis parameters on the optical properties of the synthesized AgNPs was also studied. The characterization of synthesized AgNPs by Fourier transform infrared spectroscopy, X-ray diffraction studies, UV–visible spectroscopy, scanning electron microscopy and transmission electron microscopy (TEM) revealed the formation of small AgNPs with narrow size distribution. TEM studies corroborated that the AgNPs are highly crystalline and spherical with an average diameter of 7.13 nm. The cyclic voltammetry profile of AgNPs modified electrode in NaOH depicted prominent redox peaks evidencing an impressive electrochemical response. The AgNPs manifested high catalytic activity towards reduction of methyl orange and rhodamine blue with apparent rate constant 0.3038 min−1 and 0.1542 min−1 respectively. Additionally, the prepared AgNPs exhibited strong antibacterial efficacy against the tested microbes. Green synthesis of silver nanoparticles using clammy cherry fruit extract

Investigating the Shape and Size-Dependent Optical Properties of Silver Nanostructures Using UV–vis Spectroscopy

In the laboratory experiment described here, students synthesize silver nanostructures (AgNS) with different shapes and sizes to elucidate the shape- and size-dependent optical properties of nanostructured materials. Students also develop understanding of some thermodynamic and kinetic aspects of the synthesis process through this experiment. In the size-controlled synthesis of spherical and triangular silver nanostructures, students can observe the conspicuous color change of colloidal AgNS systems. In addition, the optical properties of these materials can be analyzed qualitatively and quantitatively using UV–vis spectroscopy and dynamic light scattering. Students gain skills in synthesizing and characterizing different silver nanostructures (sphere and triangle) and learn about the shape-dependent optical properties of these nanostructures.

A green approach for the biosynthesis of powdered silver nanoparticles using leaf extract of Trigonella foenum-graecum L.: Characterization and antibacterial evaluation

Silver nanoparticles (AgNPs) were synthesized using aqueous leaf extract of Trigonella foenumgraecum as reducing and stabilizing agent. The ultraviolet-visible spectrum showed absorption peak at 480 nm. XRD pattern indicates the formation of face-centered cubic structure of silver nanoparticles. FESEM images indicate the presence of spherical silver nanoparticles with the particle size of ~90 nm. FTIR indicates that the participation of different functional groups present in the biomolecules is responsible for both reducing and stabilizing the formation of nanoparticles. The synthesized AgNPs demonstrated positive antibacterial activity against two different foodborne pathogenic bacteria (Escherichia coli O157:H7 ATCC 35150, Staphylococcus aureus ATCC 13565) with zones of inhibition of 9.20 ± 0.18 and 9.34 ± 0.11, respectively and MIC and MBC of 100 and >100 μg/ml, respectively. The synthesized AgNPs could serve as a candidate for development of antibacterial drugs or additive in the food packaging system for its application in medicine, cosmetics and food sector industries.

Simultaneous Synthesis of Silver Nanoparticles and Natural Indigo Dyeing of Wool Fiber

The wool fiber is a suitable medium for growing different microorganism. In recent years, the treatment of textiles with silver compounds as an active antibacterial agent has gained increased attention to produce advanced medical and hygiene textiles. The current work aims to synthesize silver nanoparticles through two different methods, which are silver pre-treatment and simultaneous silver treatment during indigo dyeing procedures. The formation of spherical silver nanoparticle confirmed by the appearance of a single symmetric extinction peak around 415 nm. The morphology of the indigo-dyed wool fabrics examined using scanning electron microscopy, and their colorimetric characteristics evaluated. The SEM images of wool fiber samples indicated that the silver pre-treatment method resulted in the formation of smaller micro-size (0.73 µm) platelet-like structure of indigo colorant compared with simultaneous silver treatment method (1.46 µm). The indigo-dyed wool samples without silver treatment presented lower color strength at all visible wavelengths compared with silver treatment indigo-dyed samples. Moreover, the simultaneous silver treatment method resulted in a lower color strength compare with the silver pre-treatment method, which due to lower silver content.

Antimicrobial, Antioxidant and Larvicidal Activities of Spherical Silver Nanoparticles Synthesized by Endophytic Streptomyces spp.

In this study, metabolites involved in the free-biomass filtrates for three endophytic actinomycetes of Streptomyces capillispiralis Ca-1, Streptomyces zaomyceticus Oc-5, and Streptomyces pseudogriseolus Acv-11 were used as biocatalysts for green synthesis of silver nanoparticles (Ag-NPs). Characterization of biosynthesized Ag-NPs was accomplished using UV-Vis spectroscopy, X-ray diffraction patterns (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM-EDX), transmission electron microscopy (TEM), and particle size analyzer. The biosynthesized Ag-NPs showed maximum surface plasmon resonance (SPR) at 440 for strain Ca-1 and 450 for both strains of OC-5 and Acv-11. Nanoparticle spherical shape was recorded with size ranging from 23.77 to 63.14nm, 11.32 to 36.72nm, and 11.70 to 44.73nm for Ca-1, Oc-5, and Acv-11, respectively. SEM-EDX analysis exhibited the weight percentages of 17.3, 22.3, and 48.7% for Ag-NPs synthesized by strains Ca-1, Oc-5 and Acv-11, respectively. The activities of biosynthesized Ag-NPs were concentration dependent and the obtained results confirmed the efficacy of Ag-NPs as antimicrobial agents against Gram-positive and Gram-negative bacteria as well unicellular and multicellular fungi. The MIC for Gram-positive bacteria, Gram-negative bacteria (E. coli), and eukaryotic microorganisms was 0.25mM with clear zone ranging from 10.3 to 14.6mm, while MIC for Pseudomonas aeruginosa was 1.0mM for Ag-NPs synthesized by strain Ca-1 and 0.25mM for those synthesized by strains Oc-5 and Acv-11. Moreover, Ag-NPs exhibited antimicrobial activity against four plant pathogenic fungi represented by Alternaria alternata, Fusarium oxysporum, Pythium ultimum, and Aspergillus niger at 2.0, 1.5, 1.0, and 0.5mM of Ag-NPs with different degree. In vitro assessment of the antioxidant efficacy of biosynthesized Ag-NPs was achieved by scavenging assay of H2O2, reducing power of Fe3+, or total antioxidant assay. The results showed that antioxidant activities of Ag-NPs were concentration dependent with the highest activity at Ag-NP concentration of 2.0mM. Furthermore, the biosynthesized NPs have prospective bioinsecticidal activity against Culex pipiens and Musca domestica. Green synthesis of NPs could be quite potential for the development of new bioactive compounds used in different biomedical applications.