A Green Approach for the Synthesis of Silver Nanoparticles Using Root Extract of <Emphasis Type="Italic">Chelidonium majus:</Emphasis> Characterization and Antibacterial Evaluation

In this study, silver nanoparticles (Ag-NPs) have been synthesized using extract of Chelidonium majus root in aqueous solution at room temperature. The root extract was able to reduce Ag⁺ to Ag⁰ and stabilized the nanoparticles Different physico-chemical techniques including UV–Vis spectroscopy, transmission electron microscopy and powder X-ray diffraction (PXRD) were used for the characterization of the biosynthesized Ag-NPs obtained. The surface plasmon resonance band appeared at 431 nm is an evidence for formation of Ag-NPs. TEM imaging revealed that the synthesized Ag-NPs have an average diameter of around 15 nm and with spherical shape. Moreover the crystalline structure of synthesized nanoparticles was confirmed using XRD pattern. Furthermore antimicrobial activities of synthesized Ag-NPs were evaluated against Escherichia coli -ATCC 25922 and Pseudomonas aeruginosa ATCC 2785 bacteria strain.     

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.     

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.     

Green formulation of Ag nanoparticles by Hibiscus rosa-sinensis: Introducing a navel chemotherapeutic drug for the treatment of liver cancer

An eco-friendly biosynthesized Ag NPs immobilized Hibiscus rosa-sinensis extract has been introduced. The as-prepared nanoparticles were characterized using UV–Vis, SEM, and FT-IR analysis. In the FT-IR test, the presence of many antioxidant compounds with related bonds caused the excellent condition for reducing of silver in the silver nanoparticles. In UV–Vis, the clear peak in the wavelength of 428 nm indicated the formation of silver nanoparticles. The synthesized nanoparticles had very low cell viability and high anti-liver cancer activities dose-dependently against pleomorphic hepatocellular carcinoma (SNU-387), hepatic ductal carcinoma (LMH/2A), morris hepatoma (McA-RH7777), and novikoff hepatoma (N1-S1 Fudr) cell lines without any cytotoxicity on the normal cell line (HUVEC). The synthesized nanoparticles inhibited half of the DPPH molecules in the concentration of 78 µg/mL. Perhaps notable anti-liver cancer activities of the synthesized nanoparticles against common liver cancer cell lines are linked to their antioxidant activities.     

A Novel Green Synthesis of Silver Nanoparticles Using Gum Karaya: Characterization,Antimicrobial and Catalytic Activity Studies

Stable silver nanoparticles have been synthesized using gum karaya acting as both reducing and stabilizing agent without using any synthetic reagent. The reaction is performed using water, which is an environmentally safe solvent. This reaction was carried out in an autoclave at a pressure of 15 psi and 120 °C temperature by varying the time. The influence of different parameters such as time, change of concentration of silver nitrate and concentration of gum karaya on the formation of silver nanoparticles has been studied. The synthesized silver nanoparticles are characterized by UV–Vis spectroscopy, FTIR, XRD and TEM. UV–Vis analysis of the sample confirmed the formation of silver nanoparticles exhibiting a sharp peak at a wavelength of 420 nm. TEM micrographs showed the formation of well-dispersed silver nanoparticles of size 2–4 nm. The antimicrobial activity of silver nanoparticles stabilized in gum karaya is tested against Escherichia coli, Micrococcus luteus and is found to be possessing inhibiting property. The silver nanoparticles stabilized in gum karaya exhibited very good catalytic activity and the kinetics of the reaction was found to be pseudo first order with respect to the 4-nitrophenol.     

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.     

Formulation and characterization of a novel cutaneous wound healing ointment by silver nanoparticles containing Citrus lemon leaf: A chemobiological study

IntroductionFormulating new wound-healing ointments by natural compounds is the first research priority in the developing and developed countries. This study was intended to provide green formulation of Ag-NP ointment containing Citrus lemon leaf aqueous extract and examine its capability of healing cutaneous wounds and its antioxidant and cytotoxicity activities under in vitro and in vivo conditions.Materials and methodsDifferent techniques, including UV–Vis and FT-IR spectroscopy, were used to characterize Ag-NPs. MTT assay was used to investigate cytotoxicity property of Ag-NPs. Antioxidant activity of Ag-NPs were examined by DPPH in the presence of butylated hydroxytoluene as positive control. Parameters of cutaneous wound healing were measured both histopathologically and biochemically.ResultsClear peak at 429 nm shown by UV–Vis spectroscopy indicated formation of Ag-NPs. In FT-IR spectroscopy, presence of many antioxidant compounds provided an excellent condition to reduce silver in Ag-NPs. FE-SEM and TEM images showed spherical Ag-NPs with an average size of 25.1 nm. The synthesized silver nanoparticles had excellent cell viability on the HUVECs line and indicated this method was nontoxic. Application of Ag-NP ointment improved wound healing parameters significantly (P ≤ 0.01). Ag-NPs reduced wound areas, total cells, neutrophils and lymphocytes significantly (P ≤ 0.01) and increased wound contracture, vessels, hexosamines, hydroxyl proline, hexuronic acid, fibrocytes, fibroblasts and fibrocyte/ fibroblast ratios significantly (P ≤ 0.01).ConclusionsOnce our results are verified by clinically experimental studies, Ag-NP ointment can be used as a modern one to treat several types of wounds, especially cutaneous ones, in humans.     

Biosynthesis of silver nanoparticles using <Emphasis Type="Italic">Artocarpus elasticus</Emphasis> stem bark extract

Background

Green approach in synthesizing metal nanoparticles has gain new interest from the researchers as metal nanoparticles were widely applied in medical equipment and household products. The use of plants in the synthesis of nanoparticles emerges as a cost effective and eco-friendly approach. A green synthetic route for the production of stable silver nanoparticles (Ag-NPs) by using aqueous silver nitrate as metal precursor and Artocarpus elasticus stem bark extract act both as reductant and stabilizer is being reported for the first time.

Results

The resultant Ag-NPs were characterized by UV–vis spectroscopy, powder X-Ray diffraction, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and Fourier-transform infra-red (FT-IR). The morphological study by TEM and SEM shows resultant Ag-NPs in spherical form with an average size of 5.81 ± 3.80, 6.95 ± 5.50, 12.39 ± 9.51, and 19.74 ± 9.70 nm at 3, 6, 24, and 48 h. Powder X-ray diffraction showed that the particles are crystalline in nature, with a face-centered cubic structure. The FT-IR spectrum shows prominent peaks appeared corresponds to different functional groups involved in synthesizing Ag-NPs.

Conclusions

Ag-NPs were synthesized using a simple and biosynthetic method by using methanolic extract of A. elasticus under room temperature, at different reaction time. The diameters of the biosynthesis Ag-NPs depended on the time of reaction. Thus, with the increase of reaction time in the room temperature the size of Ag-NPs increases. From the results obtained in this effort, one can affirm that A. elasticus can play an important role in the bioreduction and stabilization of silver ions to Ag-NPs.

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Graphical abstract: Figure illustrates stabilization of silver nanoparticles after formation by A. elasticus stem bark extract.

     

Synthesis of silver nanoparticles via green method using ultrasound irradiation in seaweed <Emphasis Type="Italic">Kappaphycus alvarezii</Emphasis> media

Green methods are a safer alternative to natural chemical and physical methods for the synthesis of silver nanoparticles (Ag-NPs), due to their being environmentally friendly and cost effective. This study offers a new green approach using ultrasound irradiation as the reducing agent and seaweed Kappaphycus alvarezii (K. alvarezii) as the natural bio-media. The seaweed K. alvarezii/Ag-NPs was characterised by ultraviolet–visible (UV–vis), X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscope with energy dispersive X-ray (FESEM-EDX), zeta potential, and Fourier transform infrared (FTIR) studies. UV–vis shows that surface plasmon resonance (SPR) arises from this solution due to the combined oscillations from the nanoparticles. The XRD study indicates the crystalline nature of the Ag-NPs. From the TEM images, the Ag-NPs are almost spherical with an average diameter of 11.78 nm. The FTIR spectrum provides adequate evidence of phytochemicals stabilising the nanoparticles. Synthesised Ag-NPs were successfully obtained using this green method.     

Green Synthesis of Silver Nanoparticles Using Acacia farnesiana (Sweet Acacia) Seed Extract Under Microwave Irradiation and Their Biological Assessment

In the present study, Acacia farnesiana (Sweet acacia) seed extract is used to reduce Ag⁺ → Ag⁰ under microwave irradiation. The formation of silver nanoparticles (AgNPs) is monitored by recording the UV–Vis absorption spectra for surface plasmon resonance (SPR) peak at ~450 nm. The absorbance of SPR increases linearly with increasing temperature of the reaction mixture. Rapid reduction of silver ions occurred to form AgNPs, 80–90 % yield in about 150 s. A marginal decrease in pH and increase in solution potential (E) of the reaction mixture during the formation of AgNPs are in agreement with the proposed mechanism. XRD pattern of the AgNPs agree with the fcc structure of Ag metal, and the calculated crystallite size is ~17 nm. FT-IR and solid-state ¹³C NMR spectra indicate the functional groups of flavonones and terpenoids (biomolecules from plant extract) which are adsorbed on AgNPs, thereby the present method led to in situ biofunctionalization/bio-capping of AgNPs. TG analysis shows the thermal decomposition of these plant residues present on AgNPs at about 250 °C. The spherical shape of the particles with a diameter (?) in the range of ~15–20 nm is evident from FE-SEM image. Elemental analysis by EDX analysis confirms the presence of Ag as the only major element. The in vitro antibacterial screening of AgNPs shows that these bio-capped AgNPs have higher inhibitory action for E. coli and S. aureus followed by B. subtilis and P. aeruginosa. In addition, AgNPs show very good antioxidant property.     

Green Synthesis and Characterization of Silver Nanoparticles Using Ascomycota Fungi Penicillium nalgiovense AJ12

A new method for green synthesis of silver nanoparticles using the cell-free filtrate of Penicillium nalgiovense AJ12 as reducing and protecting agent was described. The pathway is based on the reduction of Ag¹⁺ by protein(s). Various techniques such as UV–Vis spectroscopy, transmission electron microscopy (TEM), dynamic light scattering (DLS), Fourier transform infrared and Zeta potential measurements were used to characterize the silver nanoparticle obtained. The results revealed synthesis of the spherical silver nanoparticles coated with protein(s). The average size of the particles obtained from TEM was 15.2 ± 2.6 nm. DLS measurements showed that the particle size was higher than that estimated from TEM measurements and was 25.2 ± 2.8 nm. Studies on the role of the cell-free filtrate proteins in the synthesis of silver nanoparticles indicated that the process is non-enzymatic but involves amino acids interactions with silver ions. It was found that the aqueous silver nanoparticles suspensions exhibited excellent stability over a wide range of ionic strength, pH and temperature.     

<Emphasis Type="Italic">Areca catechu</Emphasis> Assisted Synthesis of Silver Nanoparticles and its Electrocatalytic Activity on Glucose Oxidation

In this work, a facile biogenic route for the synthesis of silver nanoparticles (AgNPs) is reported. The aqueous extract of Areca catechu (A. catechu) nuts are used as reducing source. The synthesized AgNPs characterized by UV–Visible (UV–Vis) spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and high resolution transmission electron microscopy (HR-TEM) with energy dispersive spectrum (EDS) analysis. The formations of AgNPs are identified from the appearance of yellow color and the surface plasmon resonance absorbance peak between 407 and 437 nm. The FT-IR results exposed that the active biomolecules of A. catechu are responsible for capping of AgNPs. The synthesized AgNPs are distorted spherical shape with 45 nm of size, identified from the HR-TEM. In application, the electrocatalytic activity of AgNPs is analyzed towards glucose oxidation using cyclic voltammetry. The results showed that A. catechu derived AgNPs act as good electrocatalyst than bare bulk silver and glassy carbon electrodes.     

Photocatalytic studies of silver doped ZnO nanoparticles synthesized by chemical precipitation method

Ag-doped ZnO nanoparticles (Zn_1?xAg_xO; where x = 0.00–0.05) were synthesized by chemical precipitation method. The synthesized products were characterized by X-ray diffraction, scanning electron microscope (SEM), transmission electron microscope (TEM) and UV–Vis spectrometer. The SEM and TEM micrographs revealed the agglomerated spherical-like morphology and the measurements show that the size of crystallites is in the range of 10–40 nm. Optical measurements indicated a red shift in the absorption band edge after Ag doping. The band gap values of as prepared undoped and doped with silver samples were found to decrease with increase in temperature from 300 to 800 °C. Photocatalytic activities of ZnO and Ag doped ZnO were evaluated by irradiating the sample solution to ultraviolet light by taking methylene blue as organic dye. The experiment demonstrated that the photo-degradation efficiency of 1 mol% Ag-doped ZnO was significantly higher than that of undoped and 2–5 mol% Ag doped ZnO under ultraviolet light irradiation.     

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.     

Phytochemical fabrication and characterization of silver nanoparticles by using Pepper leaf broth

The Pepper leaves extract acts as a reducing and capping agent in the formation of silver nanoparticles. A UV–Vis spectrum of the aqueous medium containing silver nanoparticles demonstrated a peak at 458 nm corresponding to the plasmon absorbance of rapidly synthesized silver nanoparticles that was characterized by UV–Vis spectrophotometer. The morphology and size of the benign silver nanoparticles were carried out by the transmission electron microscope (TEM) and field emission scanning electron microscope (FE-SEM). The sizes of the synthesized silver nanoparticles were found to be in the range of 5–60 nm. The structural characteristics of biomolecules hosted silver nanoparticles were studied by X-ray diffraction. The chemical composition of elements present in the solution was determined by energy dispersive spectrum. The FTIR analysis of the nanoparticles indicated the presence of proteins, which may be acting as capping agents around the nanoparticles. This study reports that synthesis is useful to avoid toxic chemicals with adverse effects in medical applications rather than physical and chemical methods.     

Green Synthesis of Silver Nanoparticles Using Arachis hypogaea (Ground Nut) Root Extract for Antibacterial and Clinical Applications

The present study focused on the green synthesis of silver nanoparticles (AgNPs) using Arachis hypogaea (ground nut) root extract for the antibacterial and clinical application. The presence of major phytochemical compounds are found to be 2H-Pyaran,2,5-diethenyltetrahydro, Didodecyl phthalate, Decanoic acid, Tetradecanoic acid, Bis(2-ethylhexyl) phthalate, Dodecanoic acid, Phosphonic acid, 2-(4-Methoxyphenyl)-5-(4-methoxynaphthyl) thiophene and Methyl 2-(N-Benzylimino)-4-chloro-3,3-dimethylbutanoate by GC–MS. Nanoparticles synthesis is confirmed by UV–Vis analysis by observing the maximum absorption spectrum at 450 nm. XRD and SEM–EDX results reveals the synthesized nanoparticles are cubic crystalline with agglomerated particles of silver oxide with biomolecules present around it. TEM images clearly shows that the biosynthesized nanoparticles are mostly spherical and irregular shaped with an average particles size of 30 nm. Highest susceptibility pattern of silver nanoparticle against Enterococcus sp. (35 ± 0.4 mm) which followed by Pseudomonas sp. (33 mm) and Staphylococcus aureus (29 mm). Green synthesized nanoparticles are coated over the commercially available clinical band aid cloth by dip coating method. Silver nanoparticle incorporated band aid cloth showed good antibacterial activity against the harmful bacteria which usually cause infection and interfere during wound healing. Our findings revealed that green nanoparticle has a good antibacterial action against harmful bacteria and showed good response for efficient clinical application.     

Exploitation of Haloferax alexandrinus for Biogenic Synthesis of Silver Nanoparticles Antagonistic to Human and Lower Mammalian Pathogens

In the present study we report the use of cells of a Haloarchaeon for the green synthesis of silver nanoparticles. Biosynthesis of AgNPs occurred within 30 s on exposure of cells of Haloferax alexandrinus to silver nitrate in direct sunlight. Maximum AgNPs production was achieved within 4 min of exposure of silver nitrate (0.05 %) to cells (5 mg/ml), at pH 7, at ambient day temperature (26–34 °C). The AgNPs had characteristic surface plasmon resonance at 420 nm in UV–Vis spectra. Spherical and irregular crystals ranging from 2 to 60 nm in size with an average size of 18 nm were observed in TEM analysis. The FTIR spectral analysis indicated involvement of N–H, –OH, C=O, C–O functional groups present in cells of Haloferax alexandrinus MTCC 3265. The biogenic AgNPs exhibited broad spectrum antimicrobial activity against human and mammalian pathogens, in the order of Pseudomonas aeruginosa ATCC 9027 > Bordetella bronchiseptica ATCC 4617 > Bacillus subtilis ATCC 6633 > Staphylococcus aureus ATCC 6538P > Staphylococcus epidermidis ATCC 12228 > Escherichia coli ATCC 8739 > Salmonella typhimurium ATCC 14028.     

Synthesis, structural and photocatalytic studies of Mn-doped CdS nanoparticles

Mn-doped CdS nanoparticles (Cd_1?x Mn _x S; where x = 0.00–0.10) were synthesized by a chemical precipitation method. The synthesized products were characterized by X-ray diffraction (XRD), scanning electron microscope, transmission electron microscope (TEM), and UV–Vis spectrometer. The XRD and TEM measurements show that the size of crystallites is in the range of 10–40 nm. Optical measurements indicated a red shift in the absorption band edge upon Mn doping. The direct allowed band gaps of undoped and Mn-doped CdS nanoparticles measured by UV–Vis spectrometer were 2.3 and 2.4 eV at 400 °C, respectively. Photocatalytic activities of CdS and Mn-doped CdS were evaluated by irradiating the solution to ultraviolet light and taking methyl orange (MO) as organic dye. It was found that 5 mol% Mn-doped CdS bleaches MO much faster than undoped CdS upon its exposure to the ultraviolet light. The experiment demonstrated that the photo-degradation efficiency of 5 mol% Mn-doped CdS was significantly higher than that of undoped CdS.     

The surface modification of spherical ZnO with Ag nanoparticles: A novel agent,biogenic synthesis,catalytic and antibacterial activities

Nowadays, the industrial wastewater pollutants including toxic dyes and pathogenic microbes have caused serious environmental contaminations and human health problems. In the present study, eco-friendly and facile green synthesis of Ag modified ZnO nanoparticles (ZnO-Ag NPs) using Crataegus monogyna (C. monogyna) extract (ZnO-Ag@CME NPs) is reported. The morphology and structure of the as-biosynthesized product were characterized by field emission scanning electron microscopy (FESEM), X-Ray diffraction (XRD), differential reflectance spectroscopy (DRS), dynamic light scattering (DLS), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), and energy-dispersive X-ray spectroscopy (EDS) techniques. TEM and FESEM images confirmed the oval and spherical-like structure of the products with a size of 55–70 nm. The EDS analysis confirmed the presence of Zn, Ag, and O elements in the biosynthesized product. The photocatalytic results showed ZnO-Ag@CME NPs were degraded (89.8% and 75.3%) and (94.2% and 84.7%) of methyl orange (MO) and basic violet 10 (BV10), under UV and sunlight irradiations, respectively. The Ag modified ZnO nanoparticles exhibited enhanced catalytic activity towards organic pollutants, and showed better performance than the pure ZnO nanoparticles under UV and sunlight irradiations. This performance was probably due to the presence of silver nanoparticles as a plasmonic material. Antibacterial activity was performed against different bacteria. ZnO-Ag@CME NPs showed high antibacterial activity against K. pneumoniae, S. typhimurium, P. vulgaris, S. mitis, and S. faecalis with MIC values of 50, 12.5, 12.5, 12.5, and 12.45 µg/mL, respectively. All in all, the present investigation suggests a promising method to achieve high-efficiency antibacterial and catalytic performance.     

Facile synthesis of mosquitocidal silver nanoparticles using Mussaenda glabra leaf extract: characterisation and impact on non-target aquatic organisms

Plant-borne compounds have been proposed for extracellular synthesis of mosquitocidal nanoparticles. However, their impact against mosquito natural enemies has been scarcely studied. Here, we synthesised silver nanoparticles (Ag NPs) using Mussaenda glabra leaf extract as reducing and stabilising agent. Biofabricated Ag NPs were characterised by UV–vis spectrophotometry, X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Compared to the leaf aqueous extract, biosynthesised Ag NPs showed higher toxicity against mosquito vectors Anopheles subpictus, Aedes albopictus and Culex tritaeniorhynchus with LC₅₀ of 17–19 μg/mL, respectively. Ag NPs were found safer to non-target organisms Diplonychus indicus and Gambusia affinis, with respective LC₅₀ values ranging from 1446 to 8628 μg/mL. Overall, M. glabra-fabricated Ag NPs are a promising and eco-friendly tool against larval populations of mosquito vectors of medical and veterinary importance, with negligible toxicity against other non-target aquatic organisms.