Sustainable green synthesis of silver nanoparticles by using Rangoon creeper leaves extract and their spectral analysis and anti‐bacterial studies

The plant‐based biological molecules possess exceptionally controlled assembling properties to make them suitable in the synthesis of metal nanoparticles. In the present study, an efficient simple one‐pot method was employed for the synthesis of silver nanoparticles (SNPs) from the Rangoon creeper (RC) aqueous leaf extract. Biomolecules present in the leaf extract play a significant role as reducing agent as well as capping agent in the formation of RC‐SNPs. The formation of RC‐SNPs was confirmed by using several analytical techniques such as Fourier‐transform infrared spectroscopy and ultraviolet–visible spectrophotometer studies. The presence of a sharp surface plasmon resonance peak at 449 nm showed the formation of RC‐SNPs. X‐ray diffraction analysis showed the crystalline nature of the RC‐SNPs with a face‐centred cubic structure. Elemental analysis of RC‐SNPs was done by using energy‐dispersive X‐ray spectroscopy and X‐ray photoelectron spectroscopy. The morphology of RC‐SNPs was examined by transmission electron microscopy (TEM) in the nano range 12 nm, and thermogravimetric‐differential thermal analysis demonstrated the mechanical strength of RC‐SNPs at various temperatures. The authors’ newly synthesised RC‐SNPs exhibited significant anti‐bacterial activity against Staphylococcus aureus and Escherichia coli. Inspec keywords: silver, nanoparticles, X‐ray photoelectron spectra, antibacterial activity, ultraviolet spectra, microorganisms, X‐ray chemical analysis, differential thermal analysis, X‐ray diffraction, transmission electron microscopy, visible spectra, nanofabrication, surface plasmon resonance, Fourier transform infrared spectra, mechanical strengthOther keywords: silver nanoparticles, ultraviolet–visible spectrophotometry, antibacterial activity, sustainable green synthesis, plant‐based biological molecules, assembling properties, reducing agent, capping agent, Fourier‐transform infrared spectroscopy, surface plasmon resonance, Rangoon creeper aqueous leaf extract, X‐ray diffraction, face‐centred cubic structure, elemental analysis, energy‐dispersive X‐ray spectroscopy, X‐ray photoelectron spectroscopy, transmission electron microscopy, TEM, thermogravimetric‐differential thermal analysis, mechanical strength, Staphylococcus aureus, Escherichia coli, Ag     

Assessment of cytotoxicity and immune compatibility of phytochemicals‐mediated biosynthesised silver nanoparticles using Cynara scolymus

The study was focused on the phytochemicals‐mediated biosynthesis of silver nanoparticles using leaf extracts and infusions from Cynara scolymus. To identify the antioxidant activity and total phenolic content, the 1,1‐diphenyl‐1‐picrylhydrazyl and Folin–Ciocalteau methods were applied, respectively. The formation and stability of the reduced silver ions were monitored by UV–vis spectrophotometer. The particle sizes of the silver nanoparticles were characterised using the dynamic light scattering technique and scanning electron microscope. The phase composition of the obtained silver nanoparticles was characterised by X‐ray diffraction. The silver nanoparticles suspension, artichoke infusion, and silver ions were separately tested towards potential cytotoxicity and pro‐inflammatory effect using mouse fibroblasts and human monocytes cell line, respectively. The total phenolic content and antioxidant activity of ethanol extract and infusion were found significantly higher as compared to aqueous extract and infusion. The UV–visible spectrophotometric analysis revealed the presence of the characteristic absorption band of the Ag nanoparticles. Moreover, it was found that with the increasing volume of plant extract, the average size of particles was increased. Biocompatibility results evidently showed that silver nanoparticles do not induce monocyte activation, however in order to avoid their cytotoxicity suspension at a concentration <2 ppm should be applied.Inspec keywords: pharmaceuticals, health and safety, renewable materials, toxicology, organic compounds, antibacterial activity, X‐ray diffraction, nanomedicine, nanoparticles, nanofabrication, suspensions, ultraviolet spectra, visible spectra, scanning electron microscopy, silver, particle sizeOther keywords: phytochemicals‐mediated biosynthesis, antioxidant activity, total phenolic content, dynamic light scattering technique, silver nanoparticles suspension, scanning electron microscopy, Cynara scolymus, 1,1 diphenyl‐1‐picrylhydrazyl method, cytotoxicity, immune compatibility, leaf extracts, UV‐vis spectrophotometry, particle size, Folin‐Ciocalteau methods, phase composition, X‐ray diffraction, artichoke infusion, pro‐inflammatory effect, mouse fibroblasts, human monocytes cell line, Ag     

Role of Ribes khorassanicum in the biosynthesis of AgNPs and their antibacterial properties

Silver nanoparticles (AgNPs) have been biosynthesised through the extracts of Ribes khorassanicum fruits, which served as the reducing agents and capping agents. Biosynthesised AgNPs have been found to be ultraviolet–visible (UV–vis) absorption spectra since they have displayed one surface plasmon resonance peak at 438 nm, attesting the formation of spherical NPs. These particles have been characterised by UV–vis, field‐emission scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, X‐ray diffraction, Fourier transform infrared spectroscopy, and transmission electron microscopy analysis. The formation of AgNPs at 1.0 mM concentration of AgNO₃ has resulted in NPs that contained mean diameters in a range of 20–40 nm. The green‐synthesised AgNPs have demonstrated high antibacterial effect against pathogenic bacteria (i.e. Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa). Biosynthesising metal NPs through plant extracts can serve as the facile and eco‐friendly alternative for chemical and/or physical methods that are utilised for large‐scale nanometal fabrication in various medical and industrial applications.Inspec keywords: X‐ray diffraction, X‐ray chemical analysis, nanofabrication, surface plasmon resonance, nanoparticles, antibacterial activity, microorganisms, scanning electron microscopy, silver, nanomedicine, visible spectra, ultraviolet spectra, transmission electron microscopy, Fourier transform infrared spectra, field emission scanning electron microscopy, biomedical materialsOther keywords: antibacterial properties, silver nanoparticles, reducing agents, capping agents, surface plasmon resonance peak, spherical NPs, field‐emission scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, X‐ray diffraction, transmission electron microscopy analysis, plant extracts, ultraviolet‐visible absorption spectra, Fourier transform infrared spectroscopy, antibacterial effect, Ribes khorassanicum fruits, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, surface plasmon resonance, AgNO₃ , Ag     

Green synthesis and evaluation of silver nanoparticles for antimicrobial and biochemical profiling in Kinnow (Citrus reticulata L.) to enhance fruit quality and productivity under biotic stress

Green synthesis of silver nanoparticles (AgNPs) by utilising plant extract is an emerging class of nanotechnology. It revolutionizes all the field of biological sciences by synthesizing chemical free AgNPs. In the present study, AgNPs were synthesised by utilising Moringa oleifera leaves as the main reducing and stabilising agent and characterised through UV–visible spectroscopy, zeta analyser, X‐ray diffraction spectroscopy (XRD), energy dispersive X‐ray (EDX), and scanning electron microscopy (SEM). The different concentrations of biosynthesised AgNPs (10, 20, 30, and 40 ppm) were exogenously applied on the already infected plants (canker) of Citrus reticulata at different day intervals. The AgNPs at a concentration of 30 ppm was found to be most suitable concentration for creating the resistance against canker disease in Citrus reticulata. The enzymatic activities were also explored and it was found that 30 ppm concentration of biosynthesised AgNPs significantly reduced the biotic stress. Fruit quality and productivity parameters were also assessed and it was found that fruit quality and productivity were significant in response to 30 ppm concentration of biosynthesised AgNPs. The present work highlights the potent role of biosynthesised AgNPs, which can be used as biological control of citrus diseases and ultimately improving the quality and productivity of Citrus.Inspec keywords: X‐ray diffraction, scanning electron microscopy, silver, X‐ray chemical analysis, biochemistry, ultraviolet spectra, atomic force microscopy, visible spectra, biotechnology, microorganisms, nanoparticles, antibacterial activity, enzymes, nanotechnology, electrokinetic effects, plant diseases, crops, product qualityOther keywords: green synthesis, silver nanoparticles, fruit quality, chemical‐free AgNP synthesis, antimicrobial activity, biochemical profiling, Citrus reticulata L, Kinnow productivity, nanotechnology, Moringa oleifera leaves, stabilising agent, UV–Visible spectroscopy, zeta analyser, energy‐dispersive X‐ray spectroscopy, X‐ray diffraction, scanning electron microscopy, atomic force microscopy, Xanthomonas axonopodis, canker disease, enzymatic activities, superoxide dismutase, peroxidase, catalase, biological control, Ag     

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     

Diospyros assimilis root extract assisted biosynthesised silver nanoparticles and their evaluation of antimicrobial activity

The current research study focuses on biosynthesis of silver nanoparticles (Ag NPs) for the first time from silver acetate employing methanolic root extract of Diospyros assimilis. The UV–Vis absorption spectrum of biologically synthesised nanoparticles displayed a surface plasmon peak at 428 nm indicating the formation of Ag NPs. The influence of metal ion concentration, reaction time and amount of root extract in forming Ag NPs by microscopic and spectral analysis was thoroughly investigated. Structural analysis from transmission electron microscopy confirmed the nature of metallic silver as face‐centered cubic (FCC) crystalline with an average diameter of 17 nm, which correlates with an average crystallite size (19 nm) calculated from X‐ray diffraction analysis. Further, the work was extended for the preliminary examination of antimicrobial activity of biologically synthesised Ag NPs that displayed promising activity against all the tested pathogenic strains.Inspec keywords: antibacterial activity, nanoparticles, silver, particle size, nanofabrication, nanomedicine, biomedical materials, ultraviolet spectra, visible spectra, optical microscopy, surface plasmon resonance, transmission electron microscopy, crystallites, X‐ray diffraction, microorganismsOther keywords: Diospyros assimilis root extract assisted biosynthesised silver nanoparticles, antimicrobial activity, silver acetate, methanolic root extract, UV‐visible absorption spectrum, biologically synthesised nanoparticles, surface plasmon peak, Ag NPs formation, metal ion concentration, reaction time, microscopic analysis, spectral analysis, structural analysis, transmission electron microscopy, metallic silver, FCC crystalline phase, average crystallite size, X‐ray diffraction analysis, pathogenic strains, Ag     

Facile phyto‐mediated synthesis of silver nanoparticles using Chinese winter jujube (Ziziphus jujuba Mill. cv. Dongzao) extract and their antibacterial/catalytic properties

The aqueous extract of Chinese winter jujube (Ziziphus jujuba Mill. cv. Dongzao) was used as reducing and capping agents for the synthesis of silver nanoparticles (AgNPs) for the first time. The resulting AgNPs were characterised by UV/Visible (UV–Vis) spectroscopy, atomic force microscope, transmission electron microscopy, selected area electron diffraction, X‐ray diffraction, scanning electron microscopy, energy‐dispersive X‐ray and Fourier transform infrared spectroscopy (FTIR). The colloidal solution of AgNPs gave a maximum UV–Vis absorbance at 446 nm. The synthesised nanoparticles were almost in the spherical shapes with an average size of 11.5 ± 4. 8 nm. FTIR spectra were applied to identify the functional groups which were possibly responsible for the conversion of metal ions into nanoparticles. The results showed that the prepared AgNPs were coated with the biomolecules in the extract. The biosynthesised AgNPs showed a remarkable catalytic activity at room temperature, and they also showed good antibacterial properties against Escherichia coli and Staphylococcus aureus.Inspec keywords: silver, nanoparticles, nanofabrication, antibacterial activity, biomedical materials, nanobiotechnology, scanning electron microscopy, X‐ray diffraction, transmission electron microscopy, ultraviolet spectra, visible spectra, X‐ray chemical analysis, Fourier transform infrared spectra, catalysisOther keywords: wavelength 446 nm, temperature 293 K to 298 K, Ag, Escherichia coli, Staphylococcus aureus, biomolecules, catalytic activity, metal ions, colloidal solution, FTIR spectra, UV‐vis absorbance, TEM, SEM, XRD, Fourier transform infrared spectroscopy, energy‐dispersive X‐ray spectroscopy, scanning electron microscopy, X‐ray diffraction, selected area electron diffraction, transmission electron microscopy, atomic force microscopy, UV‐visible spectroscopy, catalytic properties, antibacterial properties, Chinese winter jujube extract, silver nanoparticles, facile phyto‐mediated synthesis     

One pot green fabrication of metallic silver nanoscale materials using Crescentia cujete L. and assessment of their bactericidal activity

In this study, the leaf extract of an important medicinal plant Crescentia cujete L. (CC) was employed as a green reducing agent to synthesise highly‐stable C. cujete silver nanoparticles (CCAgNPs). The reduction of Ag⁺ to Ag⁰ nanoparticles was initially observed by a colour change which generates an intense surface plasmon resonance peak at 417 nm using a UV‐Vis spectrophotometer. Various optimisation factors such as temperature, pH, time and the stoichiometric proportion of the reaction mixture were performed, which influence the size, dispersity and synthesis rate of CCAgNPs. In addition, surface chemistry of synthesised CCAgNPs through Fourier transform infrared spectroscopy reveals the reducing/stabilising agent present in the aqueous extract of C. cujete and synthesised CCAgNPs. Transmission electron microscopy analysis features the spherical shape of CCAgNPs with an average size of 39.74 nm. Furthermore, an X‐ray diffraction study confirms that the synthesised CCAgNPs were face‐centred cubic crystalline in nature. The CCAgNPs display tremendous bactericidal activity against human pathogens Bacillus subtilis, Staphylococcus epidermidis, Rhodococcus rhodochrous, Salmonella typhi, Mycobacterium smegmatis, Shigella flexneri and Vibrio cholerae via penetrating into the bacterial cell membrane and causing failure of an internal chain reaction.Inspec keywords: silver, nanoparticles, nanofabrication, surface plasmon resonance, ultraviolet spectra, visible spectra, spectrochemical analysis, surface chemistry, Fourier transform infrared spectra, stoichiometry, transmission electron microscopy, X‐ray diffraction, biomembranes, cellular biophysics, antibacterial activity, nanomedicineOther keywords: one pot green fabrication, metallic silver nanoscale materials, Crescentia cujete L, bactericidal activity, silver nanoparticles, leaf extract, surface plasmon resonance, UV‐vis spectrophotometer, optimisation factors, surface chemistry, stoichiometric proportion, Fourier transform infrared spectroscopy, transmission electron microscopy, X‐ray diffraction, face‐centred cubic crystalline, human pathogens, bacterial cell membrane, Ag     

Antibacterial and dye degradation potential of zero‐valent silver nanoparticles synthesised using the leaf extract of Spondias dulcis

The present study reports a simple and low cost synthesis of zero‐valent silver nanoparticles (ZVSNPs) from silver nitrate using the leaf extract of Spondias dulcis. The ZVSNPs showed a unique peak at 420 nm in UV–vis spectrum. The SEM image portrayed cuboidal shaped particles. The EDX spectrum designated the elemental silver peak at 3 keV. In XRD, a sharp peak at 32.47° denoted the existence of (1 0 1) lattice plane and the average crystallite size was calculated as 48.61 nm. The lattice parameter was determined as 0.39 nm. The FTIR spectra of the leaf extract and ZVSNPs showed shifts in the specific functional group bands which ascertained the involvement of phytoconstituents in the formation and capping of nanoparticles. The average hydrodynamic size was measured as 59.66 nm by DLS method. A low PDI, 0.187 witnessed the monodispersity. A negative zeta potential value of −15.7 mV indicated the negative surface charges of the nanoparticles. The bactericidal action of ZVSNPs was demonstrated against two pathogens S.typhimurium and E.coli during which a dosage dependent zone of inhibition results was observed. Additionally, the catalytic potential of ZVSNPs was examined for the degradation of methylene blue dye in which an accelerated degradation of the dye was observed.Inspec keywords: antibacterial activity, crystallites, electrokinetic effects, scanning electron microscopy, nanoparticles, particle size, ultraviolet spectra, X‐ray chemical analysis, microorganisms, light scattering, nanofabrication, materials preparation, X‐ray diffraction, visible spectra, silver, dyes, Fourier transform infrared spectraOther keywords: wavelength 420.0 nm, Ag, voltage ‐15.7 mV, size 59.66 nm, size 0.39 nm, size 48.61 nm, electron volt energy 3.0 keV, Fourier transform infrared spectra, methylene blue dye, bactericidal action, dynamic light scattering, lattice parameter, Escherichia coli, Salmonella typhimurium, Spondias dulcis, negative zeta potential, polydispersity index, crystallite size, leaf extract, X‐ray diffraction, energy dispersive X‐ray spectrum, cuboidal‐shaped particles, scanning electron microscopy image, ultraviolet–visible spectrum, silver nitrate, zero‐valent silver nanoparticles     

Green synthesis of AgCl/Ag3 PO4 nanoparticle using cyanobacteria and assessment of its antibacterial,colorimetric detection of heavy metals and antioxidant properties

In this study, the extract of two strains of cyanobacteria was used for the synthesis of silver nanoparticles (NPs). UV–vis spectroscopy, X‐ray diffraction, dynamic light scattering and field emission scanning electron microscopy (FESEM) analyses were carried out to characterise the NPs. The antioxidant activity and heavy metal detection properties were investigated; moreover, their minimum inhibitory concentration and minimum bactericidal concentration against the multi‐drug resistant bacteria were determined. The most abundant materials in these extracts were carbohydrates, so the biosynthesis of NPs using exopolysaccharide (EPS) was also investigated. The surface plasmon resonance of NPs had a peak at 435 nm and EPS NPs at 350–450 nm. The NPs produced by Nostoc sp. IBRC‐M5064 extract revealed the face‐centred cubic (fcc) structure of AgCl, while NPs of N. pruniforme showed the fcc crystalline structure of Ag₃ PO₄ and AgCl. The FESEM showed the spherical shape of these NPs. The AgCl/Ag₃ PO₄ colloid, in comparison with AgCl, showed better antioxidant activity and antibacterial effect. The heavy metal detection analysis of NPs revealed that the NPs of both stains involved in Hg (NO₃)₂ detection.Inspec keywords: drugs, light scattering, silver, biochemistry, surface plasmon resonance, X‐ray diffraction, silver compounds, antibacterial activity, ultraviolet spectra, nanoparticles, visible spectra, colloids, microorganisms, nanofabrication, field emission scanning electron microscopy, chemical sensors, nanosensorsOther keywords: cyanobacteria, antibacterial detection, colorimetric detection, dynamic light scattering, antioxidant activity, heavy metal detection analysis, silver nanoparticle synthesis, field emission scanning electron microscopy analysis, UV‐visible spectroscopy analysis, X‐ray diffraction analysis, inhibitory concentration, exopolysaccharide, surface plasmon resonance, Nostoc sp. IBRC‐M5064 extract, face‐centred cubic crystalline structure, FESEM, spherical shape, antibacterial effect, multidrug resistant bacteria, wavelength 350.0 nm to 450.0 nm, AgCl‐Ag₃ PO₄ , Ag     

Efficacy of mycosynthesised AgNPs from Earliella scabrosa as an in vitro antibacterial and wound healing agent

The silver nanoparticles (AgNPs) with their unique chemical and physical properties are proving as a new therapeutical agent. In the present study, the AgNPs synthesised from an aqueous extract of a macrofungus, Earliella scabrosa, were characterised by field emission scanning electron microscopy (FESEM), energy dispersive X‐ray analysis (EDX), high‐resolution transmission electron microscopy, X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and further evaluate for its in vitro antibacterial and wound healing efficacy. The mycosynthesised AgNPs exhibited the surface plasmon resonance peak at 410 nm with good stability over a period of a month. The FESEM and EDX analyses revealed the spherical‐shaped AgNPs of an average size of 20 nm and the presence of elemental Ag, respectively. The XRD pattern showed the crystalline nature of AgNPs. The FTIR spectra confirmed the conversion of Ag⁺ ions to AgNPs due to reduction by biomolecules of macrofungus extract. The mycosynthesised AgNPs showed effective antibacterial activity against two Gram‐positive bacteria, namely Bacillus subtilis and Staphylococcus aureus, and two Gram‐negative bacteria Escherichia coli and Pseudomonas aeruginosa. The pathogens were highly sensitive to AgNPs, whereas less sensitive to AgNO₃. The mycosynthesised AgNPs showed significant wound healing potential with 68.58% of wound closure.Inspec keywords: surface plasmon resonance, wounds, X‐ray diffraction, nanoparticles, molecular biophysics, nanomedicine, antibacterial activity, biomedical materials, reduction (chemical), silver, microorganisms, X‐ray chemical analysis, nanofabrication, transmission electron microscopy, particle size, field emission scanning electron microscopy, Fourier transform infrared spectraOther keywords: high‐resolution transmission electron microscopy, healing efficacy, mycosynthesised AgNPs, spherical‐shaped AgNPs, wound healing agent, in vitro antibacterial efficacy, Earliella scabrosa, silver nanoparticles, physical properties, chemical properties, therapeutical agent, aqueous extract, macrofungus, field emission scanning electron microscopy, FESEM, energy dispersive X‐ray analysis, EDX, X‐ray diffraction, XRD, Fourier transform infrared spectroscopy, FTIR spectroscopy, surface plasmon resonance peak, crystalline nature, biomolecules, Gram‐positive bacteria, Bacillus subtilis, Staphylococcus aureus, Gram‐negative bacteria, Escherichia coli, Pseudomonas aeruginosa, pathogens, wound closure, Ag     

Eco‐friendly synthesis of silver and gold nanoparticles with enhanced antimicrobial,antioxidant, and catalytic activities

The present work is emphasised on the bio‐fabrication of silver and gold nanoparticles in a single step by a microwave‐assisted method using the leaf extract of Synedrella nodiflora as both reducing and stabilising agent. The synthesised nanoparticles are highly stable and show surface plasmon resonance peak at 413 and 535 nm, respectively, for silver and gold nanoparticles in UV–Vis spectrum. The functional group responsible for the reduction of metal ions were obtained from Fourier transform infrared spectroscopy. The crystalline nature of nanoparticles with face‐centred cubic geometry was confirmed by the X‐ray diffraction and selected area electron diffraction patterns. The morphology and sizes of the silver and gold nanoparticles were obtained from transmission electron microscopy images. The nanoparticles exhibit effective antimicrobial activities against various pathogenic strains. These antimicrobial properties were analysed by employing agar well diffusion method. The nanoparticles show significant antioxidant properties, and it was determined using 2, 2‐diphenyl‐1‐picrylhydrazyl assay. The nanoparticles also show potent catalytic activity in the degradation of anthropogenic pollutant dyes Congo red and eosin Y by excess NaBH₄. Thus, the current study demonstrates the potential use of S. nodiflora as a reducing and stabilising agent for the synthesis of silver and gold nanoparticles and their relevance in the field of biomedicine and catalysis.Inspec keywords: transmission electron microscopy, visible spectra, surface plasmon resonance, nanofabrication, ultraviolet spectra, field emission electron microscopy, reduction (chemical), nanocomposites, microorganisms, nanoparticles, dyes, silver, X‐ray diffraction, nanomedicine, gold, antibacterial activity, electron diffraction, infrared spectra, particle size, Fourier transform spectra, scanning electron microscopy, catalysis, crystal growth from solutionOther keywords: synthesised nanoparticles, gold nanoparticles, catalytic activities, electron diffraction patterns, antimicrobial activities, antioxidant activities, transmission electron microscopy images, X‐ray diffraction, 2,2‐diphenyl‐1‐picrylhydrazyl assay, Synedrella nodiflora, UV–Vis spectrum, silver nanoparticles, biofabrication, surface plasmon resonance, Fourier transform infrared spectroscopy, face‐centred cubic geometry, area electron diffraction patterns, pathogenic strains, agar well diffusion method, anthropogenic pollutant dyes, Congo red, eosin Y, wavelength 413.0 nm, wavelength 535.0 nm, Au, Ag     

Green synthesis of silver nanoparticles using Mentha pulegium and investigation of their antibacterial,antifungal and anticancer activity

A simple and eco‐friendly method for efficient synthesis of stable colloidal silver nanoparticles (AgNPs) using Mentha pulegium extracts is described. A series of reactions was conducted using different types and concentrations of plant extract as well as metal ions to optimize the reaction conditions. AgNPs were characterized by using UV–vis spectroscopy, transmission electron microscopy, atomic force microscopy, dynamic light scattering, zetasizer, energy‐dispersive X‐ray spectroscopy (EDAX) and Fourier transform infrared spectroscopy (FTIR). At the optimized conditions, plate shaped AgNPs with zeta potential value of ‐15.7 and plasmon absorption maximum at 450 nm were obtained using high concentration of aqueous extract. Efficient adsorption of organic compounds on the nanoparticles was confirmed by FTIR and EDAX. The biogenic AgNPs displayed promising antibacterial activity on Escherichia coli, Staphylococcus aureus, and Streptococcus pyogenes. The highest antibacterial activity of 25 µg mL‐1 was obtained for all the strains using aqueous extract synthesized AgNPs. The aqueous extract synthesised AgNPs also showed considerable antifungal activity against fluconazole resistant Candida albicans. The cytotoxicity assay revealed considerable anticancer activity of AgNPs on HeLa and MCF‐7 cancer cells. Overall results indicated high potential of M. pulegium extract to synthesis high quality AgNPs for biomedical applications.Inspec keywords: silver, nanoparticles, nanofabrication, botany, antibacterial activity, biomedical materials, nanomedicine, ultraviolet spectra, visible spectra, transmission electron microscopy, atomic force microscopy, X‐ray chemical analysis, Fourier transform infrared spectra, electrokinetic effects, microorganisms, cellular biophysics, cancerOther keywords: antibacterial activity, antifungal activity, anticancer activity, stable colloidal silver nanoparticle, Mentha pulegium, plant extract, UV‐visible spectroscopy, transmission electron microscopy, atomic force microscopy, DLS, zetasizer, energy‐dispersive X‐ray spectroscopy, Fourier transform infrared spectroscopy, methanolic extract, aqueous extract, plate‐shaped silver nanoparticle, zeta potential, plasmon absorption maximum, organic compounds adsorption, biogenic silver nanoparticle, Escherichia coli, Staphylococcus aureus, Streptococcus pyogenes, fluconazole‐resistant Candida albicans, MTT assay, HeLa cancer cell, MCF‐7 cancer cell, Ag     

Unveiling the cytotoxicity of phytosynthesised silver nanoparticles using Tinospora cordifolia leaves against human lung adenocarcinoma A549 cell line

Biosynthesis of silver nanoparticles (AgNPs) using plant extract is a cheap, easily accessible and natural process in which the phyto‐constituents of the plants act as capping, stabilising and reducing agent. The present study explored the biosynthesis of AgNPs using aqueous leaf extract of Tinospora cordifolia and characterised via various techniques such as Fourier transform infrared, scanning electron microscopy, transmission electron microscopy (TEM), energy dispersive X‐ray analysis and X‐ray diffraction. Here, TEM confirmed the spherical morphology with 25–50 nm size of synthesised AgNPs. Further, anticancer efficiency of AgNPs synthesised using T. cordifolia leaves were evaluated against human lung adenocarcinoma cell line A549 by MTT, trypan blue assay, apoptotic morphological changes using Annexin V‐FITC and Propidium iodide (PI), nuclear morphological changes by DAPI (4, 6‐diamidino‐2‐phenylindole dihydrochloride) staining, reactive oxygen species generation and mitochondrial membrane potential determination. Results confirmed the AgNPs synthesised using T. cordifolia leaves are found to be highly toxic against human lung adenocarcinoma cell line A549.Inspec keywords: toxicology, cellular biophysics, cancer, silver, biomembranes, drugs, nanofabrication, nanoparticles, transmission electron microscopy, drug delivery systems, nanomedicine, lung, biomedical materials, antibacterial activity, X‐ray diffraction, Fourier transform infrared spectra, scanning‐transmission electron microscopyOther keywords: cytotoxicity, phytosynthesised silver nanoparticles, A549 cell line, biosynthesis, aqueous leaf, transmission electron microscopy, TEM, X‐ray analysis, X‐ray diffraction, spherical morphology, human lung adenocarcinoma cell line, nuclear morphological changes, 4, 6‐diamidino‐2‐phenylindole dihydrochloride, Tinospora cordifolia leaves, scanning electron microscopy, Fourier transform infrared, energy dispersive X‐ray analysis, Ag, size 25.0 nm to 50.0 nm, anticancer efficiency, trypan blue assay, propidium iodide, Annexin V‐FITC, DAPI staining, reactive oxygen species generation, mitochondrial membrane potential determination     

Biocompatibility enhancement of graphene oxide‐silver nanocomposite by functionalisation with polyvinylpyrrolidone

Several materials such as silver are used to enhance graphene oxide (GO) sheets antimicrobial activity. However, these toxic materials decrease its biocompatibility and hinder its usage in many biological applications. Therefore, there is an urgent need to develop nanocomposites that can preserve both the antimicrobial activity and biocompatibility simultaneously. This work highlights the importance of functionalisation of GO sheets using Polyvinylpyrrolidone (PVP) and decorating them with silver nanoparticles (AgNPs) in order to enhance their antimicrobial activity and biocompatibility at the same time. The structural and morphological characterisations were performed by UV‐Visible, Fourier transform infrared (FTIR), and Raman spectroscopic techniques, X‐ray diffraction (XRD), and high‐resolution transmission electron microscopy (HR‐TEM). The antimicrobial activities of the prepared samples against Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans were studied. The cytotoxicity of prepared materials was tested against BJ1 normal skin fibroblasts. The results indicated that the decoration with AgNPs showed a significant increase in the antimicrobial activity of GO and FGO sheets, and functionalisation of GO sheets and GO‐Ag nanocomposite with PVP improved the cell viability about 40 and 35%, respectively.Inspec keywords: biomedical materials, nanocomposites, visible spectra, ultraviolet spectra, X‐ray diffraction, cellular biophysics, nanoparticles, Raman spectra, filled polymers, transmission electron microscopy, silver, microorganisms, antibacterial activity, nanomedicine, nanofabrication, graphene compounds, toxicology, Fourier transform infrared spectraOther keywords: graphene oxide‐silver nanocomposite, polyvinylpyrrolidone, toxic materials, biocompatibility, antimicrobial activity, morphological characterisations, structural characterisations, UV‐visible spectra, Fourier transform infrared spectra, Raman spectra, X‐ray diffraction, high‐resolution transmission electron microscopy, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, cytotoxicity, BJ1 normal skin fibroblasts, cell viability, CO‐Ag     

Green synthesis and characterisation of silver nanoparticles and their effects on antimicrobial efficacy and biochemical profiling in Citrus reticulata

The synthesis of nanoparticles by utilising plant extract has revolutionised the field of nanotechnology. In the present study, AgNPs were synthesised by utilising the leaves of Moringa oleifera as reducing and stabilising agent. UV‐visible spectroscopy showed characteristic surface plasmon band in the range of 413–420 nm. Scanning electron microscopy (SEM) elucidated rectangular segments fused together. X‐ray diffraction (XRD) analysis confirmed the crystalline nature of AgNPs and presence of metallic silver ions was confirmed by energy dispersive X‐ray (EDX). The different concentrations (10, 20, 30 and 40 ppm) of AgNPs were exogenously applied on Citrus reticulata to record the disease incidence at different day intervals. The disease intensity was progressively increased in all the applied treatments with the passage of time. The 30 ppm concentration of AgNPs was found to be most suitable concentration for creating the resistance against brown spot disease. Moreover, the effects of AgNPs were also assessed for biochemical profiling in C. reticulata. The enhanced production of endogenous enzymes and non‐enzymatic components was observed in response to 30 ppm concentration of AgNPs. The present work highlighted that green synthesised AgNPs can be as used as biological control of citrus diseases and the enhanced production of secondary metabolites antioxidants.Inspec keywords: nanoparticles, silver, nanofabrication, nanomedicine, biomedical materials, biochemistry, enzymes, molecular biophysics, plant diseases, ultraviolet spectra, visible spectra, scanning electron microscopy, surface plasmon resonance, X‐ray diffraction, X‐ray chemical analysisOther keywords: green synthesis, silver nanoparticles, antimicrobial efficacy, biochemical profiling, Citrus reticulata, plant extract, nanotechnology, medical sciences, environment friendly AgNPs, biomedical fields, leaves, Moringa oleifera, reducing agent, stabilising agent, ultraviolet‐visible spectroscopy, characteristic surface plasmon band, scanning electron microscopy, rectangular shape, X‐ray diffraction analysis, crystalline nature, energy dispersive X‐ray spectroscopy, disease incidence, disease intensity, applied treatments, Alternaria brown spot disease, total phenolic content, dry weight, total flavonoid content, T4 treatment, superoxide dismutase activity, fresh weight, maximum peroxidase production, DPPH radical scavenging assay, biological control, citrus disease, secondary metabolites antioxidants     

Biosynthesis of the CuO nanoparticles using Euphorbia Chamaesyce leaf extract and investigation of their catalytic activity for the reduction of 4‐nitrophenol

Through this study an eco‐friendly, simple, efficient, cheap and biocompatible approach to the biosynthesis and stabilisation of CuO nanoparticles (NPs) using the Euphorbia Chamaesyce leaf extract is presented. The CuO NPs were monitored and characterised by field emission scanning electron microscopy, energy dispersive X‐ray spectroscopy, Fourier transformed infrared spectroscopy, transmission electron microscope and UV‐visible spectroscopy. The biosynthesised CuO NPs showed good catalytic activity for the reduction of 4‐nitrophenol (4‐NP) in water during 180 s and reused 4 times without considerable loss of activity.Inspec keywords: copper compounds, nanoparticles, nanofabrication, catalysis, reduction (chemical), field emission electron microscopy, X‐ray chemical analysis, Fourier transform infrared spectra, transmission electron microscopy, ultraviolet spectra, visible spectraOther keywords: biosynthesis, CuO nanoparticles, Euphorbia Chamaesyce leaf extract, catalytic activity, 4‐nitrophenol reduction, nanoparticle stabilisation, field emission scanning electron microscopy, energy dispersive X‐ray spectroscopy, Fourier transformed infrared spectroscopy, transmission electron microscope, UV‐visible spectroscopy, CuO     

Synthesis and characterisation of silver nanoparticles using leaf extract of Artemisia afra and their in vitro antimicrobial and antioxidant activities

In this study, the conversion of silver ions into ∼30.74 nm sized silver nanoparticles (AgNPs) was achieved in 30 min at a reaction temperature of 80–90°C in aqueous leaf extract of Artemisia afra. The synthesised AgNPs showed surface plasmon resonance in the range of 423–438 nm. Spherical and face‐centred cubic nanoparticles were confirmed by transmission electron microscope (TEM) and X‐ray diffraction (XRD) analysis, respectively. Fourier transform infra‐red (FTIR) results indicated that the obtained nanoparticles were stabilised and capped through the carbonyl and carboxylate ion groups possibly from flavonoids, terpenoids, phenolics and esters content of the extracts. In addition, the AgNPs were assessed for their biological potentials against some microbes and, also, their free radical scavenging ability was established. The AgNPs exhibited interesting antimicrobial and antioxidant properties better than the aqueous extract of A. afra. Inspec keywords: silver, transmission electron microscopy, ultraviolet spectra, visible spectra, surface plasmon resonance, antibacterial activity, X‐ray diffraction, microorganisms, nanoparticles, nanofabrication, Fourier transform infrared spectraOther keywords: silver nanoparticles, reaction temperature, surface plasmon resonance, face‐centred cubic nanoparticles, antioxidant properties, silver ion conversion, aqueous leaf extract, carboxylate ion group, antimicrobial properties, Artemisia afra, spherical nanoparticles, TEM, XRD, FTIR spectra, Ag, temperature 80 degC to 90 degC, time 30.0 min, free radical scavenging, esters, phenolics, terpenoids, flavonoids, carbonyl ion group     

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     

Evaluation of antimicrobial activity of synthesised silver nanoparticles using Thymus kotschyanus aqueous extract

Development of a green chemistry process for the synthesis of silver nanoparticles (AgNPs) has become a focus of interest. Characteristics of AgNPs were determined using techniques, such as ultraviolet–visible spectroscopy (UV–vis), Fourier transform infrared (FTIR) analysis, scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy and X‐ray diffraction (XRD). The synthesised AgNPs using Thymus kotschyanus had the most growth inhibition against gram‐positive bacteria such as Staphylococcus aureus and Bacillus subtilise, while the growth inhibition of AgNPs at 1000–500 µg/ml occurred against Klebsiella pneumonia and at 1000–250 µg/ml of AgNPs was observed against E. coli. The UV–vis absorption spectra confirmed the formation of the AgNPs with the characteristic peak at 415 nm and SEM micrograph acknowledged spherical particles in a nanosize range. FTIR measured the possible biomolecules that are responsible for stabilisation of AgNPs. XRD analysis exhibited the crystalline nature of AgNPs and showed face‐centred cubic structure. The synthesised AgNPs revealed significant antibacterial activity against gram‐positive bacteria.Inspec keywords: visible spectra, microorganisms, ultraviolet spectra, biomedical materials, nanofabrication, nanoparticles, X‐ray diffraction, scanning electron microscopy, molecular biophysics, X‐ray chemical analysis, nanomedicine, silver, antibacterial activity, Fourier transform infrared spectraOther keywords: green chemistry process, ultraviolet–visible spectroscopy, gram‐positive bacteria, silver nanoparticles, Thymus kotschyanus aqueous extract, UV–vis spectroscopy, Fourier transform infrared spectroscopy, FTIR analysis, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, SEM micrograph, X‐ray diffraction, XRD, Staphylococcus aureus, Bacillus subtilise, Klebsiella pneumonia, E. coli, UV–vis absorption spectra, face‐centred cubic structure, antibacterial activity, antimicrobial activity, wavelength 415.0 nm, Ag