Green Synthesis of Silver Nanoparticles Using <Emphasis Type="Italic">Commiphora caudata</Emphasis> Leaves Extract and the Study of Bactericidal Efficiency

The present study reports the synthesis of silver nanoparticles (Ag NPs) from silver nitrate solution using leaf extracts of Commiphora caudata. The formation of Ag NPs in the colloidal solution is confirmed by UV–Vis spectroscopy analysis. The identification of biomolecules is analyzed through fourier transform infrared spectroscopy. X-ray diffraction pattern shows that an average particle size of the synthesized nanoparticles are in the range of 40–24 nm. Field emission scanning electron microscopy and transmission electron microscopy confirm the formation Ag NPs in spherical shape. The photoluminescence study of the synthesized Ag NPs interprets the influence of C caudata leaf concentrations on emission behavior. Zeta potential measurement is carried out to determine the stability of synthesized Ag NPs. GC–MS analysis revealed that the C. caudata contained 11 compounds, such as Stigmasterol (24.14 %), Hexacosanoic acid, methyl ester (15.13 %) and 2-bromophenyl morpholine-4-carboxylate (11.71 %). The antibacterial activity of Ag NPs shows that these bio capped Ag NPs have higher inhibitory action for Escherichia coli, Klebsiella pheumoniea, Micrococcus flavus, Pseudomonas aeruginosa, Bacillus subtilis, Bacillus pumilus, Staphylococcus aureus.     

Green synthesis of silver nanoparticles using different volumes of <Emphasis Type="Italic">Trichodesma indicum</Emphasis> leaf extract and their antibacterial and photocatalytic activities

Silver nanoparticles (Ag NPs) were prepared by a green synthesis process, using Trichodesma indicum (T. indicum) leaf extract at different (5, 10 and 15 mL) concentrations. The formation of Ag NPs was confirmed by UV–Vis spectrophotometry with surface plasmon resonance at 443 nm. After this confirmation, the influence of leaf extract concentrations on the structural and surface morphological properties was studied. Along with their physical properties, antibacterial activity against pathogenic (B. cereus and E. coli) bacteria and photocatalytic de-colorization of methylene blue (MB) were examined. The XRD studies revealed that all the nanoparticles exhibited preferential orientation along the (111) plane of silver. The crystallite size decreases as the extract concentration is increased. From SEM images, it was found that the particles are spherical in shape and the size of the particles decreased drastically when the leaf extracts concentration is greater than 10 mL. The images strongly support the result observed from the SEM studies. FT-IR analysis showed that the plant compounds are involved in the reduction of Ag⁺ ions to Ag⁰. Ag NPs synthesized in 15 mL of leaf extract greatly resist the growth of both species and decomposed 82% of MB within 210 min. This ability of Ag NPs can be due to the small spherical-shaped particles and larger Ag⁺ ion release.     

Ag nanoparticles decorated Fe<Subscript>3</Subscript>O<Subscript>4</Subscript>/chitosan nanocomposite: synthesis,characterization and application toward electrochemical sensing of hydrogen peroxide

We studied a rapid, sensitive and selective amperometric sensor for determination of hydrogen peroxide by electrodeposited Ag NPs on a modified glassy carbon electrode (GCE). The modified GCE was constructed through a step by step modification of magnetic chitosan functional composite (Fe₃O₄–CH) and high-dispersed silver nanoparticles on the surface. The resulted Ag@Fe₃O₄–CH was characterized by various analytical methods including Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, scanning electron microscopy and cyclic voltammetry. The proposed sensor employed Ag@Fe₃O₄–CH/GCE as the working electrode with a linear current response to the hydrogen peroxide concentration in a wide range from 0.01 to 400 µM with a low limit of detection (LOD = 0.0038 µM, S/N = 3). The proposed sensor showed superior reproductivity, sensitivity and selectivity for the detection of hydrogen peroxide in environmental and clinical samples.     

Facile <Emphasis Type="Italic">Aglaia elaeagnoidea</Emphasis> Mediated Synthesis of Silver and Gold Nanoparticles: Antioxidant and Catalysis Properties

A facile and green route for the synthesis of metallic nanoparticles is of significant intriguing, as it provides simple, rapid, clean, nontoxic, easily available, energy-efficient, cost-effective fabrication method. We reported environmentally benign and unexplored plant Aglaia elaeagnoidea flower extract for the synthesis of spherical and crystalline silver (Ag) and gold (Au) nanoparticles with an excellent robustness against agglomeration. The resultant nanoparticles were characterized using UV–Vis spec., FTIR, XRD, FESEM, EDAX, and TEM techniques. The uniqueness of our method lies in fast synthesis (10 min for Ag NPs) and ultra rapid homogeneous and heterogeneous complete degradation of Methylene Blue and Congo Red within few seconds using the synthesized Ag and Au NPs as the catalyst, respectively. Whereas more than 90% conversion of 4-Nitrophenol to 4-Aminophenol within few minutes for homogenous and few seconds for heterogeneous method using Ag and Au NPs were obtained. Hence, the results of this study demonstrate the possible application of biosynthesized of Ag and Au NPs as nanocatalyst in waste water treatment.     

Nanosized silver–palm pollen nanocomposite,green synthesis,characterization and antimicrobial activity

Palm pollen (PP) has been widely used in nutrition, pharmaceutical and cosmetic industries. In the present study, we explored the potential of PP in the synthesis of a silver nanoparticle (Ag NP). PP was used as both reducing and stabilizing agent. The Ag/PP nanocomposite was examined by field emission electron microscopy, X-ray diffraction, Fourier transform infrared (FT-IR) spectroscopy, ultraviolet spectroscopy and zeta potential measurement. The biosynthesized NPs showed surface plasmon resonance centered at 425 nm with an average particle size measured to be 23 nm and a zeta potential of ?30.9 mV. Prominent FT-IR signals were obtained and ascribed to phenolic and carbohydrate compounds involved in the formation of the Ag NPs, and proteins which participated in stabilization of the Ag NPs. The biologically synthesized Ag NPs were found to be extremely effective against E. coli (13.8 ± 0.25 mm) with a minimum inhibitory concentration of 20 µg/mL. Thus, such biosynthesized Ag NPs can be used in medicinal applications.     

Ag nanoparticles for determination of bisphenol A by resonance light-scattering technique

Resonance light-scattering (RLS) technique was developed for studying the interaction of silver nanoparticles (Ag NPs) with bisphenol A. A simple and environmentally friendly method was developed to synthesize Ag NPs using cinnamon extract. Synthesized nanoparticles were characterized using various measurement techniques. The synthesized Ag NPs were nearly spherical, with the sizes ranging from 30 to 60 nm. Spectral analysis indicated that the cinnamon extract acted as the reducing and capping agents on the surface of Ag NPs. RLS technique was used as the detection method. Light-scattering properties of the synthesized nanoparticles in the presence or absence of bisphenol A was selected as the detection signal. Under the optimal conditions, the linear dynamic range and RSD were found to be 0.01–10.0 mg L^?1 and 2.78% (n?=?3), respectively. A limit of detection of 0.005 mg L^?1 was obtained for the determination of bisphenol A. The obtained results showed successful application of the method for the analysis of bisphenol A in real samples.     

Toxicity of <Emphasis Type="Italic">Camellia sinensis</Emphasis>-Fabricated Silver Nanoparticles on Invertebrate and Vertebrate Organisms: Morphological Abnormalities and DNA Damages

Our understanding of nanoparticle toxicity and fate in the aquatic environment is still patchy. In the present study, the toxicity of silver nanoparticles coated by Camellia sinensis (Cs) leaf extract metabolites (Cs-AgNPs) was investigated in comparison with C. sinensis leaf extract and AgNO₃ on a micro-crustacean, Ceriodaphnia cornuta, and a fish Poecilia reticulata. 100% mortality of C. cornuta was observed post-exposure to AgNO₃ (40 µg/ml) if compared to the Cs leaf extract and Cs-AgNPs, showing 30 and 56% mortality at the same concentration, respectively. In P. reticulata 100% mortality was observed testing AgNO₃ and Cs-AgNPs post-exposure to 1 and 30 µg/ml, respectively. Light microscopy and CLSM images showed the accumulation of nanoparticles in the intestine of C. cornuta treated with Cs-AgNPs at 40 µg/ml. In addition, histological observations confirmed the abnormal tissue texture in nanoparticle-exposed P. reticulata, if compared to control fishes. Furthermore, C. cornuta and P. reticulata treated with Cs-AgNPs showed DNA damages compared to the control. Overall, these findings indicated relevant limits about the employ of silver-based pesticides in the environment, and also pointed out the Cs-AgNPs were less toxic to C. cornuta and P. reticulata if compared to silver ions.     

Electrodeposition of silver nanoparticles on a zinc oxide film: improvement of amperometric sensing sensitivity and stability for hydrogen peroxide determination

A strategy to fabricate a hydrogen peroxide (HP) sensor is developed by electrodepositing silver nanoparticles (Ag NPs) on a modified glassy carbon electrode (GCE) with a zinc oxide (ZnO) film. The Ag NPs/ZnO/GCE has been characterized by scanning electron microscopy, cyclic voltammetry, and chronoamperometry. It has been found that the Ag NPs synthesized in the presence of ZnO film provide an electrode with enhanced sensitivity and excellent stability. The sensitivity to HP is enhanced 3-fold by using Ag NPs/ZnO/GCE compared to Ag NPs/GCE. The HP sensor exhibits good linear behavior in the concentration range 2 µM to 5.5 mM for the quantitative analysis of HP with a detection limit of 0.42 µM (S/N?=?3).     

Facile Biosynthesis of Silver Nanoparticles Using <Emphasis Type="Italic">Descurainia sophia</Emphasis> and Evaluation of Their Antibacterial and Antifungal Properties

The objective of the present study was to evaluate efficiency of silver nanoparticles (Ag-NPs) biosynthesis using Descurainia sophia as a novel biological resource. The resulting synthesized Ag-NPs were characterized using UV visible spectroscopy, X-ray diffraction, transmission electron microscopy and dynamic light scattering (DLS). The UV–Vis spectra gave surface plasmon resonance at ~420 nm. TEM images revealed formation spherical shaped Ag-NPs with size ranged from to 1–35 nm. DLS confirmed uniformity of the synthesized Ag-NPs with an average size of ~30 nm. Following, the antibacterial and antifungal activities of the synthesized Ag-NPs were investigated. The concentration 25 µg/ml of the Ag-NPs showed maximum inhibitory effect on mycelium growth of Rhizoctonia solani (More than 86 % inhibition), followed by 15 µg/ml (55 % inhibition) and 10 µg/ml (63 % inhibition). The minimum inhibitory concentration and minimum bactericidal concentration of Ag-NPs against Agrobacterium tumefaciens (strain GV3850) and A, rhizogenes (strain 15843) were 4 and 8 µg/ml, respectively. The Ag-NPs were stable in vitro for 3 months without any precipitation or decrease of antifungal effects. Finally, it could be concluded that D. sophia can be used as an effective method for biosynthesis of nanoparticles, especially Ag-NPs.     

<Emphasis Type="Italic">Stachys lavandulifolia</Emphasis> and <Emphasis Type="Italic">Lathyrus</Emphasis> sp. Mediated for Green Synthesis of Silver Nanoparticles and Evaluation Its Antifungal Activity Against <Emphasis Type="Italic">Dothiorella sarmentorum</Emphasis>

In this study, silver nanoparticles (AgNPs) were biosynthesized using Stachys lavandulifolia and Lathyrus sp. The first sign of the reduction of silver ions to AgNPs was the change in color of S. lavandulifolia and Lathyrus sp. extracts changed into dark brown and auburn after treating with silver nitrate, respectively. The UV–Vis spectroscopy of reaction mixture (extract+silver nitrate) produced by S. lavandulifolia and Lathyrus sp. showed the strong adsorption peaks at ?440 and 420 nm, respectively. The transmission electron microscope images showed the synthesis of AgNPs using S. lavandulifolia and Lathyrus sp. with an average size of 7 and 11 nm, respectively. The result of X-ray diffraction pattern showed four diffraction peaks at 38°, 44°, 64°, and 77° for both types of biosynthesized AgNPs. Fourier transform infrared spectroscopy showed the possible role of involved proteins and polyhydroxyl functional groups in the synthesis process of AgNPs. Inductively coupled plasma analysis determined the conversion rate (percentage) of silver ions to silver nanoparticles in reaction mixtures of S. lavandulifolia and Lathyrus sp. 99.73 and 99.67 %, respectively. In addition, antifungal effect of AgNPs, synthesized by both extracts, was studied separately on mycelial growth of Dothiorella sarmentorum, in a completely randomized design on potato dextrose agar (PDA) medium. The inhibition rate of mycelial growth was strongly depended on the density of AgNPs and it strongly increased with increasing the density of AgNPs in the PDA medium. AgNPs more than 90 % of them inhibited from the mycelia growth of the fungus at the concentration of 40 µg/mL and higher.     

Catalytic and antibacterial evaluation of silver nanoparticles synthesized by a green approach

In this work, silver nanoparticles were synthesized using Salvia microphylla Kunth leaves extract as reducing agent and stabilizing agent. The effect of reaction time and plant extract amount on the biosynthesized nanoparticles were studied. The UV–Vis spectrum indicated that silver nanoparticles show a characteristic surface plasmon resonance at 427 nm. X-ray diffraction experiments show that the silver nanoparticles have a face-centered cubic crystal structure. The density of nanoparticles increases with increasing extract concentration and reaction time. TEM and SEM observations showed well-dispersed quasi-spherical nanoparticles sized in the range of 15–45 nm. The FT-IR analysis suggested the involvement of phenolic compounds in the reduction and stabilization of silver nanoparticles. Synthesized silver nanoparticles showed good antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. Finally, the catalytic properties of silver nanoparticles were demonstrated through the degradation of congo red and methyl orange.     

Biosynthesis,characterization, and antimicrobial effect of silver nanoparticles obtained using <Emphasis Type="Italic">Lavandula</Emphasis> × <Emphasis Type="Italic">intermedia</Emphasis>

The use..... of aqueous leaf extract of Lavandula × intermedia for biosynthesis of silver nanoparticles (AgNPs) is presented. The plant extract was obtained by boiling dried leaves and using the obtained filtrate for the synthesis of AgNPs. The study was conducted to investigate an ecofriendly approach to metal nanoparticle synthesis and to evaluate the antimicrobial potential of both the aqueous plant extract and resulting silver nanoparticles against different microbes using the disc diffusion method. The synthesis of silver nanoparticles was monitored using ultraviolet–visible (UV–v is) spectroscopy, which showed a localized surface plasmon resonance band at 411 nm and a shift of the band to higher wavenumber of 422 nm after 90 min of reaction. Powder X-ray diffraction analysis and transmission electron microscopy of the obtained AgNPs revealed their crystalline nature, with average size of 12.6 nm. Presence of elemental silver was further confirmed by energy-dispersive X-ray spectroscopy. Fourier-transform infrared spectroscopy confirmed presence of phytochemicals from Lavandula × intermedia leaf extract on the AgNPs. The AgNPs showed good antimicrobial activity with inhibition zone ranging from 10 to 23 mm; the largest inhibition zone (23 mm) occurred against Escherichia coli. Generally, the AgNPs displayed more antimicrobial activity against all investigated pathogens compared with Lavandula × intermedia leaf extract, and were also more active than streptomycin against Klebsiella oxytoca and E. coli at the same concentration. The silver nanoparticles showed prominent antimicrobial activity with a lowest minimum inhibitory concentration (MIC) value of 15 μg/mL against E. coli, K. oxytoca, and Candida albicans.     

Antibacterial behavior and physical properties of silver nanoparticle-doped ecofriendly nonwoven fabrics

A green approach for forming silver nanoparticles (Ag NPs) on ecofriendly highly absorbent nonwoven fabrics was investigated. The fiber blending ratio of highly absorbent nonwoven fabrics was optimized by simulated body fluid (SBF) and water absorption. SBF and water absorption ratios reached 42 and 42.9 times after addition of 50 wt% highly absorbent fibers. The Ag NPs were characterized by UV-visible spectrometry (UV-Vis), X-ray diffraction (XRD) and transmission electron microscopy (TEM). UV-Vis and XRD images confirmed the presence of Ag NPs. TEM observation revealed that Ag NPs were distributed at 5–10 nm. The results of antimicrobial activity showed that Ag NP dope is effective for producing antimicrobial nonwoven fabrics against E. coli and S. aureus.     

A High-Performance Catalytic and Recyclability of Phyto-Synthesized Silver Nanoparticles Embedded in Natural Polymer

The present work deals with phytogenic synthesis of Ag NPs in the natural polymer alginate as support material using Aglaia elaeagnoidea leaf extract as a reducing, capping, and stabilizing agent. Ag nanoparticles embedded in alginate were characterized using UV–Vis absorption spectroscopy, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, transmission electron microscopy techniques and selected area electron diffraction techniques. The formation of AgNPs embedded in the polymer was in spherical shape with an average size of 12 nm range has been noticed. The prepared embedded nanoparticles in polymer were evaluated as a solid heterogeneous catalyst for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) and methylene blue to leuco methylene blue in the liquid phase using sodium borohydride (NaBH₄) as reducing agent. The silver nanoparticles embedded polymer exhibited extraordinary catalytic efficacy in reduction of 4-NP to 4-AP and the rate constant is 0.5054 min^?1 at ambient conditions. The catalyst was recycled and reused up to 10 cycles without significant loss of catalytic activity. The preparation of Ag–CA composite was facile, stable, efficient, eco-friendly, easy to recycle, non-toxic, and cost effective for commercial application.     

Biogenic synthesis from <Emphasis Type="Italic">Prunus</Emphasis> × <Emphasis Type="Italic">yedoensis</Emphasis> leaf extract,characterization, and photocatalytic and antibacterial activity of TiO<Subscript>2</Subscript> nanoparticles

Green synthesis of TiO₂ nanoparticles (NPs) from Prunus × yedoensis leaf extract (PYLE), and their application for removal of phosphate and their antibacterial activity, were studied for the first time. NPs were obtained using a green chemistry approach from 0.1 M TiO₂ and PYLE at ratio of 1:1 (v/w). Initial confirmation of production of TiO₂ NPs was provided by a color change from white to light yellow, then calcination was performed at 500 °C for 1 h. The TiO₂ NPs were characterized using various analytical techniques such as ultraviolet–visible (UV–Vis) spectroscopy, X-ray diffraction analysis, Fourier-transform infrared spectroscopy, Raman spectroscopy, UV–Vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy. The results indicated that the optimal amount of TiO₂ NPs for removal of phosphate was 10 mg/l (10 ppm) with duration of 25 min. Furthermore, the antibacterial activity of TiO₂ NPs was also investigated using two different bacteria (Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli) in aqueous medium. The results revealed highly efficient sunlight-driven photocatalytic and antibacterial activity of TiO₂ NPs.     

Oxygen reduction on electrodeposited silver catalysts in alkaline solution

In this study, silver was electrochemically deposited onto glassy carbon (GC) substrate using constant potential regime and tested for oxygen reduction reaction (ORR) in alkaline media. The surface morphology of Ag/GC electrodes was studied by scanning electron microscopy (SEM). It was established that after 10 s of deposition, a number of Ag nanoparticles with the size of 15 nm are produced that grow to about 45 nm after 300 s of electrodeposition. The ORR studies were conducted in 0.1 M KOH solution employing the rotating disk electrode (RDE) method. The Tafel slope at low current densities for electrodeposited silver is in the range from ?70 to ?80 mV. The RDE measurements showed that the electron transfer number (n) is 3.5 for smaller amounts of electrodeposited Ag, and it increases with increasing the loading of Ag on the GC surface. These n values suggest that the electroreduction of oxygen on Ag/GC electrodes proceeds mainly to water.     

Nitrile functionalized silver(I) <Emphasis Type="Italic">N</Emphasis>-heterocyclic carbene complexes: DFT calculations and antitumor studies

A series of aliphatic nitrile functionalized benzimidazolium salts and their respective mononuclear N-heterocyclic carbene Ag(I)-NHC complexes are reported. The benzimidazolium salts were synthesized by N-alkylation of 1H-benzimidazole with an appropriate alkyl bromide, followed by reaction with either 5-bromovaleronitrile or 6-bromohexanenitrile. The respective mononuclear Ag(I)-NHC complexes were prepared by the reaction of the benzimidazolium salts with Ag₂O. All the synthesized compounds were characterized by physico-chemical and spectroscopic techniques. The molecular structures of the two complexes were elucidated through single-crystal X-ray diffraction analyses. Density functional theory was used to model the structures of the other complexes. The benzimidazolium salts and their complexes were screened for cytotoxicity against a breast cancer cell line (MCF-7), using the MTT assay. All the Ag(I)-NHC complexes gave IC₅₀ values ranging from 7.0 ± 1.06 to 12.9 ± 1.55 µM which are comparable to the standard drug, tamoxifen (IC₅₀ = 11.2 ± 1.84 µM), while all of the benzimidazolium salts proved to be inactive.     

A one-dimensional silver(I) coordination polymer with saccharin and pyrazine: synthesis,crystal structure,thermal analysis,FTIR spectra,and DFT studies

A silver(I) complex of saccharinate (sac) with pyrazine (pyz), [Ag(sac)(pyz)] _n , has been synthesized and characterized by elemental analysis, IR, thermal analysis, and single-crystal X-ray diffractometry. The complex crystallizes orthorhombic space group Pnma with unit cell parameters of a = 13.0073(9) Å, b = 6.4907(6) Å, c = 13.4007(9) Å, V = 1131.37(15) Å³, and Z = 4. [Ag(sac)(pyz)] _n is a one-dimensional coordination polymer, in which the sac ligand acts as a monodentate ligand through the N atom and the trigonal silver centers are linked by the bridging pyz ligands. The individual chains are connected into two-dimensional supramolemular network by aromatic π(sac)···π(pyz) stacking interactions. The FTIR spectrum of [Ag(sac)(pyz)] _n has been recorded in the region and 4,000–400 cm^?1. The optimized geometry, frequency, and intensity of the vibrational bands of [Ag(sac)(pyz)] _n were obtained by density functional theory (DFT) at the B3LYP level. The vibrational frequencies were calculated and the scaled values have been compared with the experimental FTIR data. The observed and calculated frequencies are found to be in good agreement.     

Peak shape analysis of Ag 3d core‐level X‐ray photoelectron spectra of Au@Ag core‐shell nanoparticles using an asymmetric Gaussian–Lorentzian mixed function

This article reports on the peak shape analysis of X‐ray photoelectron spectra of gold‐silver core‐shell (Au@Ag) nanoparticles (NPs) using an asymmetric Gaussian–Lorentzian mixed function. Unlike Ag NPs, Au@Ag NPs have no oxide peak and show asymmetric line shape with a high energy tail in Ag 3d core‐level spectra. A monotonic increase in the Ag 3d binding energy and a decrease in the degree of asymmetry with increasing the Ag shell thickness were observed supporting the occurrence of charge transfer from Au core to Ag shell. Copyright © 2012 John Wiley & Sons, Ltd.     

Orchids as Sources of Novel Nanoinsecticides? Efficacy of <Emphasis Type="Italic">Bacillus sphaericus</Emphasis> and <Emphasis Type="Italic">Zeuxine gracilis</Emphasis>-Fabricated Silver Nanoparticles Against Dengue,Malaria and Filariasis Mosquito Vectors

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. Insecticides from natural products may boost the effectiveness of vector control programs. In this study, we tested silver nanoparticles (AgNPs) fabricated using the leaf extract of the orchid Zeuxine gracilis as reducing agent, and the microbial pesticide Bacillus sphaericus, against the mosquitoes Anopheles stephensi, Aedes aegypti and Culex quinquefasciatus. The synthesis of AgNP was confirmed analyzing the excitation of surface Plasmon resonance using ultraviolet–visible (UV–Vis) spectrophotometry. SEM and TEM showed the irregular shapes of AgNPs. EDX spectroscopy, FTIR spectroscopy, X-ray diffraction and dynamic light scattering analysis were carried out. AgNPs were highly effective against the larvae of An. stephensi (LC₅₀ = 8.48 µg/mL), Ae. aegypti (LC₅₀ = 10.39 µg/mL) and Cx. quinquefasciatus (LC₅₀ = 13.21 µg/mL), respectively. Combined treatments testing B. sphaericus with AgNPs were also effective against An. stephensi (LC₅₀ = 12.32 µg/mL), Ae. aegypti (LC₅₀ = 14.78 µg/mL) and Cx. quinquefasciatus (LC₅₀ = 19.19 µg/mL). Overall, this study suggests that the orchid-synthesized AgNPs can be a rapid, environmentally safer bio-pesticide to be used in synergy with B. sphaericus to control mosquito vectors.