Biosynthesis of AgNPs by B. maydis and its antifungal effect against Exserohilum turcicum

In the present study, Bipolaris maydis was used to synthesise silver nanoparticles (AgNPs). Several parameters that influence the synthesis of AgNPs such as fungus age, the concentration of Ag nitrate (AgNO₃), and incubation time were explored to find the optimum synthesis condition. Furthermore, the antifungal activity of AgNPs against Exserohilum turcicum was determined by measuring inhibition zone diameter, colony formation, and conidia germination. The optimal biosynthesis system included fungus age of 7 days, 8 mM AgNO₃, and an incubation time of 120 h. Under these conditions, synthesised NPs were near round, and the average particle size was about 21 nm. At the experiment, the diameter of the inhibition zone reached a maximum of 8 mM AgNO₃ and 72 h. In addition, the inhibition rate of colony and conidia reached 83.39 and 100%, respectively, with 200 μg/ml AgNPs. The results offer a novel pathway for phytopathogen control and make it likely to develop new eco‐friendly antimicrobial.Inspec keywords: silver, nanoparticles, antibacterial activity, microorganisms, particle size, nanomedicine, nanofabricationOther keywords: biosynthesis, B. maydis, antifungal effect, Exserohilum turcicum, Bipolaris maydis, silver nanoparticles, fungus age, silver nitrate concentration, incubation time, inhibition zone diameter, colony formation, conidia germination, particle size, phytopathogen control, time 72 h, time 120 h, Ag     

Autoclave‐assisted synthesis of AgNPs in Z. officinale extract and assessment of their cytotoxicity,antibacterial and antioxidant activities

In this study, the authors synthesised silver nanoparticles (AgNPs) using autoclave as a simple, unique and eco‐friendly approach. The effect of Zingiber officinale extract was evaluated as a reducing and stabiliser agent. According to transmission electron microscopy results, the AgNPs were in the spherical shape with a particle size of ∼17 nm. The biomedical properties of AgNPs as antibacterial agents and free radical scavenging activity were estimated. Synthesised AgNPs showed significant 1,1‐diphenyl‐2‐picryl‐hydrazyl free radical scavenging. Strong bactericidal activity was shown by the AgNPs on Gram‐positive and Gram‐negative bacteria. A maximum inhibition zone of ∼14 mm was obtained for epidermidis at a concentration of 60 μg/ml for sample fabricated at 24 h. The AgNPs also showed a significant cytotoxic effect against MCF‐7 breast cancer cell lines with an half maximal inhibitory concentration value of 62 μg/ml in 24 h by the MTT assay. It could be concluded that Z. officinale extract can be used effectively in the production of potential antioxidant and antimicrobial AgNPs for commercial application.Inspec keywords: nanoparticles, cancer, organic compounds, antibacterial activity, particle size, microorganisms, silver, visible spectra, ultraviolet spectra, biomedical materials, biochemistry, nanofabrication, free radicals, nanomedicine, toxicology, cellular biophysics, transmission electron microscopyOther keywords: unique approach, eco‐friendly approach, zingiber officinale, reducing agent, stabiliser agent, transmission electron microscopy results, antibacterial agents, free radical scavenging activity, synthesised AgNPs, 1‐diphenyl‐2‐picryl‐hydrazyl free radical scavenging, strong bactericidal activity, antimicrobial AgNPs, autoclave‐assisted synthesis, antioxidant activities, cytotoxic effect, silver nanoparticles, autoclave, time 24.0 hour     

Antifungal effect of green synthesised silver nanoparticles against Setosphaeria turcica

Green synthesis of silver nanoparticles (AgNPs) is an interesting issue of the nanoscience and nanotechnology due to their unique properties. In the present study, Ginkgo biloba L. leaf extract was used to synthesise AgNPs. The effects of quantity of leaves, concentration of Ag nitrate (AgNO₃), reaction temperature, and pH were studied to discover the optimal synthesis system. In addition, antifungal effect of AgNPs against Setosphaeria turcica was measured through inhibition zone method. The optimal biosynthesis system contained 15 g of leaf, 8 mM AgNO₃, and 80°C at pH 9.0. Under mentioned conditions, the resulting synthesised NPs were nearly spherical, with an average size of 14 nm. In tests, AgNPs synthesised at different pH resulted in different inhibition zones, diameters increased gradually at pH from 3.0 to 11.0, while antifungal effect reached maximum at 9.0. Results of this study offer a new approach for biological control plant pathogenic fungi, and it has potential application for screening novel fungistats with high efficiency and low toxicity.Inspec keywords: antibacterial activity, silver, nanoparticles, nanobiotechnology, pHOther keywords: antifungal effect, green synthesised silver nanoparticles, Setosphaeria turcica, nanoscience, nanotechnology, Ginkgo biloba L. leaf extract, reaction temperature, pH, inhibition zone method, inhibition zones, mass 15 g, temperature 80 degC, size 14 nm, Ag     

Comparative study of antifungal effect of green and chemically synthesised silver nanoparticles in combination with carbendazim,mancozeb, and thiram

This study reports synthesis and characterisation of silver nanoparticles and their effect on antifungal efficacy of common agricultural fungicides. Silver nanoparticles were synthesised using biological and chemical reduction methods employing Elettaria cardamomum leaf extract and sodium citrate, respectively. Nanoparticles were then characterised using UV–Visible spectroscopy, X‐ray diffraction (XRD), transmission electron microscopy, and dynamic light scattering (DLS). While XRD assigned particles size of 31.86 nm for green and 41.91 nm for chemical silver nanoparticles with the help of the Debye–Scherrer formula, DLS specified monodisperse nature of both suspensions. Nanoparticles were tested individually and in combination with fungicides (carbendazim, mancozeb, and thiram) against fungal phytopathogens. Silver nanoparticles exhibited good antifungal activity and minimum inhibitory concentration (MIC) was observed in the range of 8–64 µg/ml. Also, they positively influenced the efficacy of fungicides. The mean MIC value (mean ± SD) for combination of all three fungicides with green AgNPs was 1.37 ± 0.6 µg/ml and for chemical AgNPs was 1.73 ± 1.0 µg/ml. Hence, it could be concluded that green AgNPs performed better than chemical AgNPs. Synergy was observed between green AgNPs and fungicides against Fusarium oxysporum. In conclusion, this study reports synthesis of monodisperse silver nanoparticles which serve as efficient antifungal agents and also enhance the fungicidal action of reported agricultural fungicides in combination studies.Inspec keywords: X‐ray diffraction, reduction (chemical), visible spectra, ultraviolet spectra, microorganisms, particle size, nanomedicine, nanofabrication, nanoparticles, agrochemicals, antibacterial activity, transmission electron microscopy, silver, light scattering, scanning electron microscopyOther keywords: antifungal effect, green silver nanoparticles, chemically synthesised silver nanoparticles, carbendazim, mancozeb, thiram, antifungal efficacy, common agricultural fungicides, biological reduction methods, chemical reduction methods, transmission electron microscopy, XRD assigned particles size, chemical silver nanoparticles, green AgNPs, chemical AgNPs, monodisperse silver nanoparticles, antifungal activity, agricultural fungicides, Elettaria cardamomum leaf extract, sodium citrate, UV‐visible spectroscopy, X‐ray diffraction, dynamic light scattering, size 31.86 nm, size 41.91 nm     

Size dependent effects of antifungal phytogenic silver nanoparticles on germination,growth and biochemical parameters of rice (Oryza sativa L), maize (Zea mays L) and peanut (Arachis hypogaea L)

Advancement in materials synthesis largely depends up on their diverse applications and commercialisation. Antifungal effects of phytogenic silver nanoparticles (AgNPs) were evident, but the reports on the effects of the same on agricultural crops are scant. Herein, we report for the first time, size dependent effects of phytogenic AgNPs (synthesised using Stevia rebaudiana leaf extract) on the germination, growth and biochemical parameters of three important agricultural crops viz., rice (Oryza sativa L), maize (Zea mays L) and peanut (Arachis hypogaea L). AgNPs with varied sizes were prepared by changing the concentration and quantity of the Stevia rebaudiana leaf extract. As prepared AgNPs were characterized using the techniques, such as high‐resolution transmission electron microscopy, particle size and zeta potential analyser. The measured (dynamic light scattering technique) average sizes of particles are ranging from 68.5 to 116 nm. Fourier transform infrared studies confirmed the participation of alcohols, aldehydes and amides in the reduction and stabilisation of the AgNPs. Application of these AgNPs to three agricultural crop seeds (rice, maize and peanut) resulted in size dependent effects on their germination, growth and biochemical parameters such as, chlorophyll content, carotenoid and protein content. Further, antifungal activity of AgNPs also evaluated against fungi, Aspergillus niger.Inspec keywords: antibacterial activity, silver, nanoparticles, nanomedicine, biochemistry, crops, transmission electron microscopy, Fourier transform infrared spectra, electrokinetic effects, organic compounds, particle size, plant diseases, microorganismsOther keywords: fungi, Aspergillus niger, size 68.5 nm to 116 nm, silver particles, phytoextract, amide functional groups, aldehydes, alcohols, Fourier transform infrared studies, zeta potential analyser, particle size, high‐resolution transmission electron microscopy, Stevia plant leaf extract, agricultural crops, antifungal effects, materials synthesis, Arachis hypogaea L, peanut, Zea mays L, maize, Oryza sativa L, rice, biochemical parameters, growth, germination, antifungal phytogenic silver nanoparticles, size dependent effects     

Plant‐mediated green synthesis of silver nanoparticles using Trifolium resupinatum seed exudate and their antifungal efficacy on Neofusicoccum parvum and Rhizoctonia solani

In recent years, biosynthesis and the utilisation of silver nanoparticles (AgNPs) has become an interesting subject. In this study, the authors investigated the biosynthesis of AgNPs using Trifolium resupinatum (Persian clover) seed exudates. The characterisation of AgNPs were analysed using ultraviolet–visible spectroscopy, X‐ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier transform infra‐red spectroscopy. Also, antifungal efficacy of biogenic AgNPs against two important plant‐pathogenic fungi (Rhizoctonia solani and Neofusicoccum Parvum) in vitro condition was evaluated. The XRD analysis showed that the AgNPs are crystalline in nature and have face‐centred cubic geometry. TEM images revealed the spherical shape of the AgNPs with an average size of 17 nm. The synthesised AgNPs were formed at room temperature and kept stable for 4 months. The maximum distributions of the synthesised AgNPs were seen to range in size from 5 to 10 nm. The highest inhibition effect was observed against R. solani at 40 ppm concentration of AgNPs (94.1%) followed by N. parvum (84%). The results showed that the antifungal activity of AgNPs was dependent on the amounts of AgNPs. In conclusion, the AgNPs obtained from T. resupinatum seed exudate exhibit good antifungal activity against the pathogenic fungi R. solani and N. Parvum.Inspec keywords: silver, nanoparticles, botany, ultraviolet spectra, visible spectra, X‐ray diffraction, transmission electron microscopy, Fourier transform infrared spectra, nanobiotechnology, biological techniquesOther keywords: plant‐mediated green synthesis, silver nanoparticles, Trifolium resupinatum seed exudate, antifungal efficacy, Neofusicoccum parvum, Rhizoctonia solani, biosynthesis, ultraviolet–visible spectroscopy, X‐ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, plant‐pathogenic fungi, XRD analysis, TEM images, antifungal activity, temperature 293 K to 298 K, Ag     

Green synthesis,characterisation and biological evaluation of plant‐based silver nanoparticles using Quercus semecarpifolia Smith aqueous leaf extract

The development of reliable and green methods for the fabrication of metallic nanoparticles (NPs) has many advantages in the field of nanotechnology. In this direction, the present work describes an eco‐friendly and cost‐effective protocol for the production of silver NPs (AgNPs) using an aqueous extract of Quercus semecarpifolia leaves. Different techniques were carried out for the characterisation of the synthesised AgNPs. The ultraviolet–visible spectroscopic analysis showed the highest absorbance peak at 430 nm. The particle size and structure were confirmed by scanning electron microscopy as well as transmission electron microscopy (TEM) analysis. From TEM imaging, it was revealed that the formed particles were spherical with an average size of 20–50 nm. The crystalline nature of the NPs was determined by X‐ray powder diffraction patterns. Thermogravimetry and differential thermal analysis were also evaluated by a temperature increment from 100 to 1000°C. Bio‐inspired synthesis of AgNPs was performed for their pharmacological evaluation in relation to the activities of the crude methanolic, n ‐hexane, chloroform, ethyl acetate, and aqueous extracts. Good cytotoxic activity was exhibited by the green‐synthesised AgNPs (77%). Furthermore, the AgNPs were found to exhibit significant antioxidant activity at 300 μg/ml (82%). The AgNPs also exhibited good phytotoxic potential (75%).Inspec keywords: scanning electron microscopy, toxicology, visible spectra, particle size, nanofabrication, nanomedicine, transmission electron microscopy, silver, ultraviolet spectra, differential thermal analysis, nanoparticles, X‐ray diffraction, botany, biochemistry, cellular biophysicsOther keywords: green synthesis, biological evaluation, plant‐based silver nanoparticles, reliable methods, metallic nanoparticles, eco‐friendly cost‐effective protocol, silver NPs, ultraviolet–visible spectroscopic analysis, highest absorbance peak, particle size, structure, transmission electron microscopy analysis, TEM imaging, crystalline nature, X‐ray powder diffraction patterns, differential thermal analysis, pharmacological evaluation, aqueous extracts, good cytotoxic activity, significant antioxidant activity, AgNPs exhibited good phytotoxic potential, bio‐inspired synthesis, Quercus semecarpifolia Smith aqueous leaf extract, scanning electron microscopy, thermogravimetry, crude methanolic, n‐hexane, chloroform, ethyl acetate, phytotoxic potential, haemagglutination activity, size 20.0 nm to 50.0 nm, wavelength 430.0 nm, temperature 100 degC to 1000 degC, Ag     

Efficacy of biogenic silver nanoparticles against clinical isolates of fungi causing mycotic keratitis in humans

Mycotic keratitis is mainly responsible for vision loss caused by various fungi. Sometimes, proper treatment of such infection is not possible due to unavailability of effective antifungal agents and development of resistance of such fungi to antimycotic drugs. Hence, it is necessary to search for potential antifungal agents, which can effectively eradicate fungal infection of eyes. Nanoparticles‐based antifungal drugs overcome this problem by increasing permeability and properties of drug molecules. In the present study, silver nanoparticles were synthesised by using Helminthosporium sp. and Chaetomium sp. following sequential reduction technique. The synthesised silver nanoparticles were detected primarily by UV‐visible spectrophotometer showing absorption spectra at 424 and 433 nm, respectively. Nanoparticles tracking analysis confirmed the mean particle size of silver nanoparticles as 45 and 55 nm. The synthesised AgNPs showed significant antifungal activity against fungi causing mycotic keratitis, when used alone and in combination with ketoconazole and amphotericin B in the range of 30–70 microgram per millilitre of minimum inhibitory concentration. Thus, the synthesised AgNPs can be used to enhance the activities of ketoconazole and amphotericin B.Inspec keywords: silver, nanoparticles, nanomedicine, antibacterial activity, diseases, permeability, ultraviolet spectra, visible spectra, particle sizeOther keywords: biogenic silver nanoparticles, fungi, mycotitic keratitis, vision loss, infection, antifungal agents, antimycotic drugs, antifungal drugs, permeability, Helminthosporium sp, Chaetomium sp, sequential reduction technique, UV‐visible spectrophotometer, mean particle size, ketoconazole, amphotericin B, wavelength 424 nm, wavelength 433 nm, size 45 nm, size 55 nm, Ag     

Green preparation of seaweed‐based silver nano‐liquid for cotton pathogenic fungi management

Silver nanoparticles (Ag NPs) were synthesised using the crude ethyl acetate extracts of Ulva lactuca and evaluated their bioefficacy against two crop‐damaging pathogens. The sets of lattice planes in the XRD spectrum for the Ag NPs were indexed to the 111, 200, 220 and 311 orientations and support the crystalline nature of the Ag NPs. The 3414 and 2968 cm⁻¹ peaks were observed in crude algal thallus extract and they were characteristic of terpenoids. Further, a peak at 1389 cm⁻¹ was observed as fatty acids. The marine macroalgae terpenoids and palmitic acid acted as reducing agent and stabiliser, respectively. The size (3 and 50 nm) and shape (spherical) of Ag NPs were recorded. The energy‐dispersive X‐ray spectroscopy analysis exemplified the presence of silver in its elemental nature. Moreover, U. lactuca Ag NPs were effective against two cotton phytopathogens namely Fusarium oxysporum f.sp. vasinfectum (FOV) and Xanthomonas campestris pv. malvacearum (XAM). The minimum inhibitory concentration was found to be 80.0 and 43.33 μg ml⁻¹ against FOV and XAM, respectively. Results confirmed the anti‐microbial activity of green nanoparticles against select pathogens and suggest their possible usage in developing antifungal agents for controlling destructive pathogens in a cotton agroecosystem.Inspec keywords: nanoparticles, biotechnology, antibacterial activity, silver, microorganisms, X‐ray chemical analysis, crops, X‐ray diffraction, cottonOther keywords: crude ethyl acetate extracts, crop‐damaging pathogens, lattice planes, XRD spectrum, crystalline nature, crude algal thallus, fatty acids, marine macroalgae terpenoids, palmitic acid, energy‐dispersive X‐ray spectroscopy analysis, elemental nature, cotton phytopathogens, green nanoparticles, destructive pathogens, cotton agroecosystem, green preparation, seaweed‐based silver nanoliquid, cotton pathogenic fungi management, silver nanoparticles, Ag NP, Ag     

Antimicrobial potential and in vitro cytotoxicity study of polyvinyl pyrollidone‐stabilised silver nanoparticles synthesised from Lysinibacillus boronitolerans

The main emphasis herein is on the eco‐friendly synthesis and assessment of the antimicrobial potential of silver nanoparticles (AgNPs) and a cytotoxicity study. Silver nanoparticles were synthesised by an extracellular method using bacterial supernatant. Biosynthesised silver nanoparticles were characterised by UV‐vis spectroscopy, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy, dynamic light scattering, and zeta potential analysis. The synthesised silver nanoparticles exhibited a characteristic peak at 420 nm. TEM analysis depicted the spherical shape and approximately 20 nm size of nanoparticles. Silver nanoparticles carry a charge of −33.75 mV, which confirms their stability. Biogenic polyvinyl pyrrolidone‐coated AgNPs exhibited significant antimicrobial effects against all opportunistic pathogens (Gram‐positive and Gram‐negative bacteria, and fungi). Silver nanoparticles equally affect the growth of both Gram‐positive and Gram‐negative bacteria, with a maximum inhibition zone observed at 22 mm and a minimum at 13 mm against Pseudomonas aeruginosa and Fusarium graminearum, respectively. The minimum inhibitory concentration (MIC) of AgNPs against P. aeruginosa and Staphylococcus aureus was recorded at between 15 and 20 μg/ml. Synthesised nanoparticles exhibited a significant synergistic effect in combination with conventional antibiotics. Cytotoxicity estimates using C2C12 skeletal muscle cell line via 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) test and lactate dehydrogenase assay were directly related to the concentration of AgNPs and length of exposure. On the basis of the MTT test, the IC50 of AgNPs for the C2C12 cell line was approximately 5.45 μg/ml concentration after 4 h exposure.     

Bacteriocin‐capped silver nanoparticles for enhanced antimicrobial efficacy against food pathogens

Bacteriocins produced by lactic acid bacteria are safer alternatives to the more popularly used chemical preservatives which exhibit several adverse effects. The bacteriocins have an advantage of being efficient in controlling food pathogens without possessing any side‐effects. However, the bacteriocins have a limitation of exhibiting a narrow antimicrobial spectrum and having a high‐dosage requirement. With an aim to combat these limitations, the present study involved the biosynthesis of bacteriocin‐capped nanoparticles, using two bacteriocins (Bac4463 and Bac22) extracted and purified from Lactobacillus strains. Nanoconjugates synthesised at optimum conditions were characterized using various physico‐chemical techniques. The interaction of bacteriocin‐capped silver nanoparticles with the pathogenic bacteria was observed using scanning electron microscopy, wherein the deformed and elongated cells were clearly visible. In vitro antimicrobial efficacy of both Bac4463‐capped silver nanoparticles and Bac22‐capped silver nanoparticles against different food pathogens was observed to be enhanced in comparison to the antimicrobial activity of bacteriocins alone. Minimum inhibitory concentration was observed to be as low as 8 μg/ml for Bac4463‐capped silver nanoparticles against Staphylococcus aureus, and 2 μg/ml for Bac22‐capped silver nanoparticles against Shigella flexneri. This study, therefore, recommends the use of bacteriocin‐capped nanoparticles as food preservatives to control the growth of food spoiling bacteria.Inspec keywords: preservatives, elongation, food safety, silver, biotechnology, antibacterial activity, food preservation, nanoparticles, nanofabrication, food products, scanning electron microscopy, microorganismsOther keywords: bacteriocins, chemical preservatives, food pathogens, bacteriocin‐capped nanoparticles, bacteriocin‐capped silver nanoparticles, Bac4463‐capped silver nanoparticles, Bac22‐capped silver nanoparticles, enhanced antimicrobial efficacy     

Seed germination and biochemical profile of Citrus reticulata (Kinnow) exposed to green synthesised silver nanoparticles

The biosynthesis of silver nanoparticles (AgNPs) is substantial for its applications in different fields. The Moringa oleifera leaves were used as reducing and stabilising agent for the biosynthesis of AgNPs. The synthesised AgNPs were characterised through UV–visible spectroscopy, zeta analyser, scanning electron microscopy (SEM) and energy dispersive Xray (EDX). In this study, effects of the synthesised AgNPs were also evaluated on nucellus tissues germination frequency and biochemical parameters of plant tissues. Nucellus tissues of Citrus reticulata were inoculated on MS medium supplemented with 10, 20, 30 and 40 µg/ml suspension of the synthesised AgNPs. Green synthesised AgNPs enhanced the in vitro germination because of low toxicity and nonfriendly issues. Significant results were obtained for germination parameters i.e. root and shoot length and seedling vigour index in response to 30 µg/ml suspension of green synthesised AgNPs. The 30 µ/ml suspension of AgNPs also enhanced antioxidant activity (41%) and SOD activity (0.36 nM/min/mg FW) while total phenolic content (4.7 µg/mg FW) and total flavonoid content (1.1 µg/mg FW) was significantly high when MS medium was fortified with 40 µg/ml suspension of the synthesised AgNPs. The content of total protein was significant (558 µg/BSA Eq/mg FW) in control plantlets as compared to the other treatments.Inspec keywords: antibacterial activity, ultraviolet spectra, X‐ray chemical analysis, proteins, microorganisms, biochemistry, nanofabrication, silver, nanotechnology, visible spectra, surface plasmon resonance, nanoparticles, suspensions, nanomedicine, scanning electron microscopy, electrokinetic effectsOther keywords: green synthesised silver nanoparticles, superoxide dismutase activity, biochemical profile, UV–visible spectroscopy, Citrus reticulata, green synthesised suspension, EDX detector, zeta potential, scanning electron microscopy, SEM, energy dispersive X‐ray, EDX, total phenolic content, total flavonoid content, size 423.0 nm to 425.0 nm, size 8.0 nm to 28.0 nm     

Biogenic synthesis of silver nanoparticles from Cassia fistula (Linn.): In vitro assessment of their antioxidant,antimicrobial and cytotoxic activities

The present study reports on biogenic‐synthesised silver nanoparticles (AgNPs) derived by treating Ag ions with an extract of Cassia fistula leaf, a popular Indian medicinal plant found in natural habitation. The progress of biogenic synthesis was monitored time to time using a ultraviolet–visible spectroscopy. The effect of phytochemicals present in C. fistula including flavonoids, tannins, phenolic compounds and alkaloids on the homogeneous growth of AgNPs was investigated by Fourier‐transform infrared spectroscopy. The dynamic light scattering studies have revealed an average size and surface Zeta potential of the NPs as, −39.5 nm and −21.6 mV, respectively. The potential antibacterial and antifungal activities of the AgNPs were evaluated against Bacillus subtilis, Staphylococcus aureus, Candida kruseii and Trichophyton mentagrophytes. Moreover, their strong antioxidant capability was determined by radical scavenging methods (1,1‐diphenyl‐2‐picryl‐hydrazil assay). Furthermore, the AgNPs displayed an effective cytotoxicity against A‐431 skin cancer cell line by 3‐(4, 5‐dimethylthiazol‐2‐yl)‐2, 5‐diphenyltetrazolium bromide (MTT) assay, with the inhibitory concentration (IC₅₀) predicted as, 92.2 ± 1.2 μg/ml. The biogenically derived AgNPs could find immense scope as antimicrobial, antioxidant and anticancer agents apart from their potential use in chemical sensors and translational medicine.Inspec keywords: antibacterial activity, biomedical materials, cancer, cellular biophysics, electrokinetic effects, Fourier transform infrared spectra, light scattering, microorganisms, nanomedicine, nanoparticles, silver, skin, spectrochemical analysis, toxicology, ultraviolet spectra, visible spectraOther keywords: Ag, voltage ‐21.6 mV, size ‐39.5 nm, A‐431 skin cancer cell line, cytotoxicity, 1,1‐diphenyl‐2‐picryl‐hydrazil assay, radical scavenging methods, Trichophyton mentagrophytes, Candida kruseii, Staphylococcus aureus, Bacillus subtilis, surface zeta potential, dynamic light scattering studies, Fourier‐transform infrared spectroscopy, alkaloids, phenolic compounds, tannins, flavonoids, phytochemical effect, ultraviolet‐visible spectroscopy, Cassia fistula leaf extract, biogenic‐synthesised silver nanoparticles, cytotoxic activities, antimicrobial activities, antioxidant activities     

Effects of saponin capped triangular silver nanocrystals on the germination of Pisum sativum,Cicer arietinum,Vigna radiata seeds & their subsequent growth study

In this study, saponin capped triangular silver nanocrystals have been synthesised using fenugreek seed extract, where the extract acts both as a reducing and capping agent. X‐ray diffraction study confirms the purity and crystalline nature of the prepared nanocrystals and transmission electron microscopic study shows the triangular morphology with the average edge length of 72 nm, along with the atomic force microscopy study for the height or the width of the triangular nanocrystals. These nanocrystals have been investigated against a few pulses (seeds) such as Pisum sativum, Cicer arietinum and Vigna radiata for their effect on the germination as well as growth of root and shoot. Considering different concentration of silver nanocrystals solution, it has been found that 25 × 10⁻⁴ and 80 × 10⁻⁴ μg/ml are the minimum and maximum concentrations of silver nanocrystals, within this range, germination and subsequent growth of root and shoot are effective. The result shows significant positive influence on the growth of root and shoot of all seeds in comparison to those of unexposed control germination. Therefore, the result of this experiment has confirmed that the use of saponin capped silver nanocrystals enhances the germination and growth of plants.Inspec keywords: transmission electron microscopy, atomic force microscopy, nanofabrication, silver, nanostructured materials, X‐ray diffraction, crystal morphology, nanobiotechnology, botanyOther keywords: Pisum sativum, saponin capped nanocrystals, nanocrystals solution, atomic force microscopy, transmission electron microscopy, reducing agent, Vigna radiata seeds, Cicer arietinum, unexposed control germination, triangular nanocrystals, triangular morphology, x‐ray diffraction study, fenugreek seed     

Green synthesis,characterisation and biological studies of AgNPs prepared using Shivlingi (Bryonia laciniosa) seed extract

Green synthesis of silver nanoparticles (AgNPs) using Shivlingi (Bryonia laciniosa) seed extract was carried out. Characterisation of synthesised nanoparticles was accomplished through the optical absorption and photoluminescence spectrum, X‐ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. The XRD analysis further confirmed the size of nanoparticles ∼15 nm. TEM images revealed homogeneous spherical ∼10 nm Bryonia extract capped AgNPs. The biological studies indicated that both Bryonia seed extract and the nanoparticles lack anti‐microbial activity; however, the nanoparticles had better cytotoxicity and total antioxidant activity. The Lethal concentration (LC)₅₀ value of water extract and the nanoparticles were found to be 1091 and 592 μg/ml, respectively. The lower LC₅₀ of nanoparticles indicates that it is more cytotoxic than the crude extract. The results indicate that the Bryonia seed is safe to be used as a medicine and the formation of their nanoparticle has further enriched the chemical reactivity, energy absorption and biological mobility.Inspec keywords: silver, nanoparticles, nanomedicine, particle size, microorganisms, cellular biophysics, nanofabrication, photoluminescence, X‐ray diffraction, transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectra, Raman spectra, antibacterial activity, biochemistryOther keywords: green synthesis, biological studies, Shivlingi seed extraction, Bryonia laciniosa, silver nanoparticles, optical absorption, photoluminescence spectrum, X‐ray diffraction, transmission electron microscopy, scanning electron microscopy, SEM, Fourier transform infrared spectroscopy, Raman spectroscopy, XRD analysis, nanoparticle size, TEM images, homogeneous spherical images, antioxidant activity, water extraction, chemical reactivity, energy absorption, biological mobility, Ag     

Biofilm reduction,cell proliferation,anthelmintic and cytotoxicity effect of green synthesised silver nanoparticle using Artemisia vulgaris extract

Infectious diseases are caused by etiological agents. Nanotechnology has been used to minimise the effect of clinical pathogens which have resistance to antibiotics. In current research synthesis, characterisation and biological activities of green synthesised nanoparticles using Artemisia vulgaris extract have been done. The characterisation of AgNPs was carried out using Fourier transform infrared spectroscopy, UV‐Vis spectrophotometry, and scanning electron microscopy. Anti‐biofilm, cell viability, antibacterial, brine shrimp lethality, and deoxyribonucleic acid protection effects have been screened. UV‐Vis spectra showed the absorption peak of synthesised nanoparticles at 400 nm. FT‐IR indicated the involvement of the functional group in the preparation of AgNPs. SEM showed the spherical shape of AgNPs with 30 nm diameter. Biological screening results revealed the antibacterial effect against clinical bacterial pathogens. Biofilm reduction and cell viability assay also supported the antibacterial effect. Cytotoxicity effect was recorded as 100% at 200 μg/ml through brine shrimp lethality assay. Protein kinase inhibition zones recorded for AgNPs (16 mm bald) compared with A. vulgaris extract (11 mm bald). It has been concluded that green synthesised AgNPs are more effective against infectious pathogens and could be used as a potential source for therapeutic drugs.Inspec keywords: cellular biophysics, toxicology, silver, nanoparticles, nanomedicine, diseases, microorganisms, ultraviolet spectra, visible spectra, Fourier transform infrared spectra, enzymes, molecular biophysicsOther keywords: biofilm reduction, cell proliferation, anthelmintic effect, cytotoxicity effect, green synthesised silver nanoparticle, Artemisia vulgaris extract, infectious diseases, aetiological agents, Fourier transform infrared spectroscopy, UV‐Vis spectrophotometry, scanning electron microscopy, SEM, antibiofilm, cell viability, brine shrimp lethality, deoxyribonucleic acid protection effects, AgNP, cytotoxicity, protein kinase inhibition zones, therapeutic drugs     

Green synthesis of silver nanoparticles using Rubia tinctorum extract and evaluation the anti‐cancer properties in vitro

Cancer is one of the leading causes of human death. Nanotechnology could offer new and optimised anticancer agents in order to fight cancer. It was shown that metal nanoparticles, in particular silver nanoparticles (AgNPs) were effective in cancer therapy. In this study, AgNPs were synthesised using Rubia tinctorum L. extract (Ru‐AgNPs). Then, cytotoxicity effects of the Ru‐AgNPs against MDA‐MB‐231 carcinoma cell line and human dermal fibroblast as normal cell line were performed. Furthermore, anti‐apoptotic effects of Ru‐AgNPs on these cancer and normal cell lines were compared using acridine orange/propidium iodide staining, flow cytometry analysis and real‐time qPCR in apoptosis gene markers. Results of UV‐vis spectroscopy showed that Ru‐AgNPs have a peak at 430 nm, which indicated synthesis of AgNPs. Ru‐AgNPs had spherical shape and average size of 12 nm. Ru‐AgNPs have cytotoxicity on MDA‐MB‐231 cells and decrease cancerous cell viability (IC50 = 4 µg/ml/48 h). Ru‐AgNPs could induce apoptosis in MDA‐MB‐231 cells through upregulation of Bax and downregulation of Bcl‐2 gene expression. The results opened up new avenues to develop Rubia based metal complexes as an anticancer agent.Inspec keywords: cellular biophysics, genetics, cancer, toxicology, nanoparticles, nanofabrication, nanomedicine, silver, biomedical materials, ultraviolet spectra, visible spectraOther keywords: Ru‐AgNPs, MDA‐MB‐231 carcinoma cell line, normal cell line, cancerous cell viability, in vitro anticancer properties, green synthesis, silver nanoparticles, Rubia tinctorum L. extract, cytotoxicity effects, human dermal fibroblast HFF, antiapoptotic effects, acridine orange‐propidium iodide staining, flow cytometry analysis, real‐time qPCR, apoptosis gene markers, UV‐visible spectroscopy, spherical shape, Bcl‐2 gene expression, Ag     

Evaluation of the toxicities of silver and silver sulfide nanoparticles against Gram‐positive and Gram‐negative bacteria

In this study, the endogenous lipid signalling molecules, N ‐myristoylethanolamine, were explored as a capping agent to synthesise stable silver nanoparticles (AgNPs) and Ag sulphide NPs (Ag₂ S NPs). Sulphidation of the AgNPs abolishes the surface plasmon resonance (SPR) maximum of AgNPs at 415 nm with concomitant changes in the SPR, indicating the formation of Ag₂ S NPs. Transmission electron microscopy revealed that the AgNPs and Ag₂ S NPs are spherical in shape with a size of 5–30 and 8–30 nm, respectively. AgNPs and Ag₂ S NPs exhibit antimicrobial activity against Gram‐positive and Gram‐negative bacteria. The minimum inhibitory concentrations (MIC) of 25 and 50 μM for AgNPs and Ag₂ S NPs, respectively, were determined from resazurin microtitre plate assay. At or above MIC, both AgNPs and Ag₂ S NPs decrease the cell viability through the mechanism of membrane damage and generation of excess reactive oxygen species.Inspec keywords: cellular biophysics, biomembranes, transmission electron microscopy, nanomedicine, microorganisms, molecular biophysics, antibacterial activity, nanofabrication, silver, biomedical materials, surface plasmon resonance, nanoparticles, materials preparation, silver compounds, lipid bilayersOther keywords: Gram‐negative bacteria, Gram‐positive bacteria, endogenous lipid signalling molecules, N‐myristoylethanolamine, capping agent, silver nanoparticles, Ag sulphide NPs, sulphidation, surface plasmon resonance, concomitant changes, transmission electron microscopy, minimum inhibitory concentrations, resazurin microtitre plate assay, cell viability, membrane damage, reactive oxygen species, Ag toxicities, Ag, Ag₂ S     

Sunlight induced biosynthesis of silver nanoparticle from the bark extract of Amentotaxus assamica D.K. Ferguson and its antibacterial activity against Escherichia coli and Staphylococcus aureus

Green synthesis of nanoparticles has gained importance due to its eco‐friendly, low toxicity and cost effective nature. This study deals with the biosynthesis of silver nanoparticles (AgNPs) from the bark extract of Amentotaxus assamica. The AgNPs have been synthesised by reducing the silver ions into stable AgNPs using the bark extract of Amentotaxus assamica under the influence of sunlight irradiation. The characterisation of the biosynthesised AgNPs was carried out by UV–vis spectroscopy, X‐ray diffraction analysis (XRD), Fourier transform infrared spectroscopy, scanning electron microscopy (SEM) and energy dispersive X‐ray analysis. The UV–vis spectrum showed a broad peak at 472 nm. Also, the XRD confirmed the crystalline structure of the AgNPs. Moreover, the SEM analysis revealed that the biosynthesised AgNPs were spherical in shape. Also, dynamic light scattering techniques were used to evaluate the size distribution profile of the biosynthesised AgNPs. Furthermore, the biosynthesised AgNPs showed a prominent inhibitory effect against both Escherichia coli (MTCC 111) and Staphylococcus aureus (MTCC 97). Thus the biosynthesis of AgNPs from the bark extract of Amentotaxus assamica is found to eco‐friendly way of producing AgNPs compared to chemical method.Inspec keywords: X‐ray chemical analysis, microorganisms, transmission electron microscopy, nanoparticles, toxicology, scanning electron microscopy, ultraviolet spectra, particle size, Fourier transform spectra, X‐ray diffraction, antibacterial activity, visible spectra, infrared spectra, nanomedicine, silverOther keywords: stable AgNP, biosynthesised AgNP, SEM analysis, sunlight irradiation, silver ions, silver nanoparticle, amentotaxus assamica, biosynthesis, escherichia coli     

Biogenic synthesis,characterisation and antifungal activity of gum kondagogu‐silver nano bio composite construct: assessment of its mode of action

The biogenic synthesis of silver nanoparticles was achieved by using gum kondagogu (Cochlospermum gossypium), a natural biopolymer (Gk‐AgNPs). Synthesised nanoparticles were characterised by using UV–visible spectroscopy, inductively coupled plasma‐atomic emission spectrometer, X‐ray diffraction, transmission electron microscope techniques. The silver nano particle size determined was found to be 3.6 ± 2.2 nm. The synthesised Gk‐AgNPs showed antifungal activity and exhibited minimum inhibitory concentration and minimal fungicidal concentration values ranging from 3.5 to 6.5 µg mL⁻¹ against Aspergillus parasiticus (NRRL‐2999) and Aspergillus flavus (NRRL‐6513). Scanning electron microscopy–energy dispersive spectroscopy analysis revealed morphological changes including deformation, shrunken and ruptured mycelium of the fungi. At the biochemical level, the mode of action revealed that there was an elevated level of reactive oxygen species, lipid peroxidation, superoxide dismutase, and catalase enzyme activity. Increased oxidative stress led to increased outer membrane damage, which was confirmed by the entry of N ‐phenyl naphthylamine to the phospholipid layer of outer membrane and higher levels of K⁺ release from the fungi treated with Gk‐AgNPs. This study explores the possible application of biogenic silver nanoparticles produced from gum kondagogu as potent antifungal agents. The potent antifungal activity of Gk‐AgNPs gives scope for its relevance in biomedical application and as a seed dressing material.Inspec keywords: antibacterial activity, nanocomposites, silver, nanofabrication, nanoparticles, biomedical materials, polymers, visible spectra, ultraviolet spectra, atomic emission spectroscopy, X‐ray diffraction, transmission electron microscopy, scanning electron microscopy, microorganisms, X‐ray chemical analysis, enzymes, lipid bilayers, biomembranes, biomechanics, nanomedicineOther keywords: antifungal activity, gum kondagogu‐silver nanobiocomposite, Cochlospermum gossypium, natural biopolymer, UV‐visible spectroscopy, inductively coupled plasma‐atomic emission spectrometer, X‐ray diffraction, transmission electron microscope, fungicidal concentration, Aspergillus parasiticus, Aspergillus flavus, scanning electron microscopy, SEM‐energy dispersive spectroscopy, fungi deformation, ruptured mycelium, reactive oxygen species, lipid peroxidation, superoxide dismutase, catalase enzyme activity, oxidative stress, membrane damage, N‐phenyl naphthylamine, phospholipid layer, potassium ion release, biogenic silver nanoparticle, antifungal agent, seed dressing material, Ag