Nitrobacter sp. extract mediated biosynthesis of Ag2 O NPs with excellent antioxidant and antibacterial potential for biomedical application

In this study, extracellular extract of plant growth promoting bacterium, Nitrobacter sp. is used for the bioconversion of AgNO₃ (silver nitrate) into Ag₂ O (silver oxide nanoparticles). It is an easy, ecofriendly and single step method for Ag₂ O NPs synthesis. The bio‐synthesized nanoparticles were characterized using different techniques. UV‐Vis results showed the maximum absorbance around 450 nm. XRD result shows the particles to have faced centered cubic (fcc) crystalline nature. FTIR analysis reveals the functional groups that are involved in bioconversion such as C–N, N–H and C=O. Energy‐dispersive X‐ray spectroscopy (EDAX) spectrum confirms that the prepared nanoparticle is Ag₂ O NPs. Particle size distribution result reveals that the average particle size is around 40 nm. The synthesized Ag₂ O NPs found to be almost spherical in shape. Biosynthesized Ag₂ O NPs possess good antibacterial activity against selected Gram positive and Gram negative bacterial strains namely Salmonella typhimurium, Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae when compared to standard antibiotic. In addition, Ag₂ O NPs exhibits excellent free radical scavenging activity with respect to dosage. Thus, this study is a new approach to use soil bacterial extract for the production of Ag₂ O NPs for biomedical application.Inspec keywords: nanomedicine, nanoparticles, silver compounds, antibacterial activity, ultraviolet spectra, visible spectra, X‐ray diffraction, Fourier transform infrared spectra, X‐ray chemical analysis, particle size, free radicalsOther keywords: free radical scavenging activity, Ag₂ O, AgNO₃ , Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Salmonella typhimurium, Gram negative bacterial strains, Gram positive bacterial strains, particle size distribution, energy‐dispersive X‐ray spectroscopy spectrum, functional groups, Fourier transform infrared analysis, faced centred cubic crystalline nature, XRD, UV‐Vis results, bio‐synthesised nanoparticles, silver oxide nanoparticles, silver nitrate bioconversion, plant growth promoting bacterium, extracellular extract, biomedical application, antibacterial potential, antioxidant potential, Ag₂ O NPs, extract mediated biosynthesis, Nitrobacter sp     

Evaluation of antibacterial property of hydroxyapatite and zirconium oxide‐modificated magnetic nanoparticles against Staphylococcus aureus and Escherichia coli

In the first section of this research, superparamagnetic nanoparticles (NPs) (Fe₃ O₄) modified with hydroxyapatite (HAP) and zirconium oxide (ZrO₂) and thereby Fe₃ O₄ /HAP and Fe₃ O₄ /ZrO₂ NPs were synthesised through co‐precipitation method. Then Fe₃ O₄ /HAP and Fe₃ O₄ /ZrO₂ NPs characterised with various techniques such as X‐ray photoelectron spectroscopy, X‐ray diffraction, scanning electron microscopy, energy dispersive X‐ray analysis, Brunauer–Emmett–Teller, Fourier transform infrared, and vibrating sample magnetometer. Observed results confirmed the successful synthesis of desired NPs. In the second section, the antibacterial activity of synthesised magnetic NPs (MNPs) was investigated. This investigation performed with multiple microbial cultivations on the two bacteria; Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Obtained results proved that although both MNPs have good antibacterial properties, however, Fe₃ O₄ /HAP NP has greater antibacterial performance than the other. Based on minimum inhibitory concentration and minimum bactericidal concentration evaluations, S. aureus bacteria are more sensitive to both NPs. These nanocomposites combine the advantages of MNP and antibacterial effects, with distinctive merits including easy preparation, high inactivation capacity, and easy isolation from sample solutions by the application of an external magnetic field.Inspec keywords: nanocomposites, X‐ray chemical analysis, microorganisms, magnetic particles, scanning electron microscopy, precipitation (physical chemistry), nanomagnetics, X‐ray diffraction, X‐ray photoelectron spectra, nanoparticles, superparamagnetism, iron compounds, antibacterial activity, biomedical materials, nanomedicine, calcium compounds, nanofabrication, Fourier transform infrared spectra, magnetometers, zirconium compoundsOther keywords: antibacterial effects, antibacterial property, superparamagnetic nanoparticles, X‐ray photoelectron spectroscopy, X‐ray diffraction, X‐ray analysis, antibacterial activity, bactericidal concentration, S. aureus bacteria, Staphylococcus aureus, Escherichia coli, hydroxyapatite, coprecipitation method, scanning electron microscopy, energy dispersive X‐ray analysis, Brunauer‐Emmett‐Teller method, Fourier transform infrared spectroscopy, vibrating sample magnetometer, microbial cultivations, nanocomposites     

Biogenic synthesis of Au,Ag and Au–Ag alloy nanoparticles using Cannabis sativa leaf extract

Biogenic synthesis of gold (Au), silver (Ag) and bimetallic alloy Au–Ag nanoparticles (NPs) from aqueous solutions using Cannabis sativa as reducing and stabilising agent has been presented in this report. Formation of NPs was monitored using UV–visible spectroscopy. Morphology of the synthesised metallic and bimetallic NPs was investigated using X‐ray diffraction and scanning electron microscopy. Elemental composition and the surface chemical state of NPs were confirmed by energy dispersive X‐ray spectroscopy analysis. Fourier transform‐infrared spectroscopy was utilised to identify the possible biomolecules responsible for the reduction and stabilisation of the NPs. Biological applicability of biosynthesised NPs was tested against five bacterial strains namely Klebsiella pneumonia, Bacillus subtilis (B. subtilis), Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa (P. aeruginosa) and Leishmania major promastigotes. The results showed considerable antibacterial and anti‐leishmanial activity. The Au–Ag bimetallic NPs showed improved antibacterial activity against B. subtilis and P. aeruginosa as compared to Au and Ag alone, while maximum anti‐leishmanial activity was observed at 250 μg ml⁻¹ NP concentration. These results suggest that biosynthesised NPs can be used as potent antibiotic and anti‐leishmanial agents.Inspec keywords: silver, silver alloys, gold, gold alloys, nanoparticles, nanofabrication, reduction (chemical), ultraviolet spectra, visible spectra, X‐ray diffraction, scanning electron microscopy, X‐ray chemical analysis, Fourier transform infrared spectra, microorganisms, antibacterial activityOther keywords: biogenic synthesis, Cannabis sativa leaf extract, bimetallic alloy Au–Ag nanoparticles, aqueous solutions, reducing agent, stabilising agent, UV–visible spectroscopy, X‐ray diffraction, scanning electron microscopy, elemental composition, surface chemical state, energy dispersive X‐ray spectroscopy analysis, Fourier transform‐infrared spectroscopy, biomolecules, bacterial strains, Klebsiella pneumonia, Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Leishmania major promastigotes, antibacterial activity, anti‐leishmanial activity, Ag, Au, AuAg     

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     

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     

Biosynthesis of waste pistachio shell supported silver nanoparticles for the catalytic reduction processes

Silver nanoparticles (NPs) are immobilised on pistachio shell surface by Cichorium intybus L. leaves extract as an antioxidant media. The Fourier transform infrared spectra, X‐ray diffraction, field‐emission scanning electron microscopy equipped with energy‐dispersive X‐ray spectroscopy, and transmission electron microscope analyses confirmed the support of silver NPs on the pistachio shell (Ag NPs/pistachio shell). Ag NPs on the pistachio shell had a diameter basically in the 10–15 nm range. Reduction reactions of 4‐nitrophenol (4‐NP), and organic dyes at ambient condition were used in the investigation of the catalytic performance of the prepared catalyst. Through this research, the Ag NPs/pistachio shell shows a high activity and recyclability, and reusability without loss of its catalytic activity.Inspec keywords: transmission electron microscopy, nanoparticles, X‐ray diffraction, catalysis, nanofabrication, dyes, X‐ray chemical analysis, reduction (chemical), silver, catalysts, Fourier transform infrared spectra, field emission scanning electron microscopyOther keywords: waste pistachio shell, silver nanoparticles, catalytic reduction processes, pistachio shell surface, antioxidant media, infrared spectra, X‐ray diffraction, field‐emission scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, transmission electron microscope analyses, reduction reactions, catalytic performance, catalytic activity, Cichorium intybus L. leaves extract, size 10.0 nm to 15.0 nm, Ag     

Antineoplastic and antioxidant potential of phycofabricated silver nanoparticles using microalgae Chlorella minutissima

This study for the first time reports on fresh water microalgae Chlorella minutissima aqueous extract (CmAe) which was utilized for the biogenic synthesis of silver nanoparticles and tested their antineoplastic potential against Liver Hepatocellular Carcinoma (HepG2) cell line. The characteristic colour change of the reaction mixture from greenish yellow to yellowish brown confirmed the synthesis of Chlorella minutissima silver nanoparticles (CmAgNPs). Microscopic analysis revealed CmAgNPs to be spherical‐shaped with particle size ranging from 10 to 30 nm. The carbohydrates and proteins distinctive peaks were observed in Fourier transform infrared spectroscopy (FTIR) spectra which suggested these biomolecules acted as reducing and capping agents. Further, the crystalline nature of CmAgNPs was confirmed by X‐ray diffraction (XRD) analysis. CmAgNPs showed maximum free radical scavenging proving it to be more potent antioxidant agent as compared to CmAe. The mortality rate of HepG2 cells treated with CmAgNPs was found to be 91.8 % at 120 μg/ml with IC₅₀ value 12.42 ± 1.096 μg/ml after 48 h whereas no effect was observed on normal Human Embryonic Kidney (HEK 293) cells. Fluorescent images of the treated HepG2 cells revealed the formation of apoptotic bodies, condensed nuclei and cell shrinkage indicating their effectiveness against the cancer cells.Inspec keywords: silver, nanoparticles, nanomedicine, microorganisms, cellular biophysics, nanofabrication, scanning electron microscopy, transmission electron microscopy, atomic force microscopy, proteins, Fourier transform infrared spectra, molecular biophysics, X‐ray chemical analysis, X‐ray diffraction, kidney, cancer, biomedical materialsOther keywords: antineoplastic potential, antioxidant potential, phycofabricated silver nanoparticle, Chlorella minutissima, freshwater microalgae, aqueous extract, liver hepatocellular carcinoma cell line, CmAgNP synthesis, field emission scanning electron microscopy, high‐resolution transmission electron microscopy, atomic force microscopy, dynamic light scattering, carbohydrate, protein, Fourier transform infrared spectroscopy, biomolecule, energy‐dispersive X‐ray spectroscopy, elemental silver signal, CmAgNP crystalline, X‐ray diffraction analysis, antioxidant agent, HepG2 cell mortality rate, human embryonic kidney, HEK 293 cell, fluorescent image, apoptotic body formation, condensed nuclei, cell shrinkage, cancer cell, antineoplastic agent, 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     

Biosynthesis of Ag3 PO4 nanoparticles in the absence of phosphate source using a phosphorus mineralising bacterium

Silver phosphate nanoparticles were biologically synthesised, for the first time, using a dilute silver nitrate solution as the silver ion supplier, and without any source of phosphate ion. The applied bacterium was Sporosarcina pasteurii formerly known as Bacillus pasteurii which is capable of solubilising phosphate from soils. It was speculated that the microbe accumulated phosphate from the organic source during the growth period, and then released it to deionised water. According to the transmission electron microscopy images and X‐ray diffraction results, the produced nanoparticles were around 20 nm in size and identified as silver phosphate nanocrystals. The outcomes were also approved by energy‐dispersive X‐ray analysis, thermogravimetric and differential scanning calorimetry analyses, ultraviolet–visible spectroscopy, and Fourier transform infrared spectroscopy analysis. Finally, the antibacterial effect of the obtained nanoparticles was verified by testing them against Bacillus cereus, Staphylococcus aureus, Escherichia coli, and Salmonella typhimurium. The activity of silver phosphate nanoparticles against gram‐negative strains was better than the gram positives. It should be mentioned that the concentrations of 500 and 1000 mg/l were found to be strongly inhibitory for all of the strains.Inspec keywords: nanoparticles, silver compounds, nanofabrication, microorganisms, antibacterial activity, transmission electron microscopy, X‐ray diffraction, X‐ray chemical analysis, differential scanning calorimetry, ultraviolet spectra, visible spectra, Fourier transform infrared spectraOther keywords: biosynthesis, phosphate source, phosphorus mineralising bacterium, silver phosphate nanoparticles, Sporosarcina pasteurii, Bacillus pasteurii, deionised water, transmission electron microscopy images, X‐ray diffraction, energy‐dispersive X‐ray analysis, thermogravimetric analyses, differential scanning calorimetry analyses, ultraviolet–visible spectroscopy, Fourier transform infrared spectroscopy, antibacterial effect, Bacillus cereus, Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, Ag₃ PO₄      

Removal of toxic contaminants from water by sustainable green synthesised non‐toxic silver nanoparticles

The study describes the synthesis of silver nanoparticles using 21 different plant extracts having medicinal properties. Molecular ultraviolet‐visible spectroscopy shows that the λ _max of nanoparticles synthesised by different plant extracts varied and ranged between 400 and 468 nm. The ultraviolet results revealed that although synthesis of nanoparticles occurred by all plant extracts successfully, their size varies, this was further confirmed by differential light scattering. The synthesised nanoparticles were investigated for their antimicrobial properties. The most promising silver nanoparticles Ocimum sanctum and Artemisia annua assisted were further characterised using transmission electron microscopy and energy dispersive X‐ray spectroscopy (EDX). EDX data confirms that synthesised nanoparticles are highly pure. Further these two plant assisted nanoparticles were studied for chemocatalytic and adsorptive properties. The silver nanoparticles from Ocimum sanctum can catalyse the reduction of 4‐nitrophenol (63%) within 20 min in the presence of NaBH₄, whereas Artemisia annua assisted silver nanoparticles did not show significant chemocatalytic activity. Both the promising nanoparticles can efficiently adsorb textile dyes from aqueous solutions. These synthesised nanoparticles were also exploited to remove microbial and other contaminants from Yamuna River water. The nanoparticles show excellent antimicrobial properties and can be reused repeatedly.Inspec keywords: antibacterial activity, nanofabrication, silver, dyes, light scattering, visible spectra, microorganisms, X‐ray diffraction, transmission electron microscopy, X‐ray chemical analysis, catalysis, nanoparticles, ultraviolet spectra, adsorption, reduction (chemical)Other keywords: sustainable green synthesised nontoxic silver nanoparticles, silver nitrate, molecular ultraviolet–visible spectroscopy, plant assisted nanoparticles, plant extracts, Ocimum sanctum, Artemisia annua, E. coli, C. albicans, plasmon absorbance, differential light scattering, energy dispersive X‐ray spectroscopy, 4‐nitrophenol, chemocatalytic activity, Yamuna River water, antimicrobial properties, time 20.0 min, time 5.0 min to 240.0 hour, size 1.0 nm to 5.0 nm, size 5.0 nm to 20.0 nm, wavelength 400.0 nm to 468.0 nm, NaBH₄ , Ag     

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     

Effect of Ag‐NPs synthesised by Chamaemelum nobile extract on the inflammation and oxidative stress induced by carrageenan in mice paw

An environmentally friendly and rapid procedure was developed to synthesise silver nanoparticles (Ag‐NPs) by Chamaemelum nobile extract and to evaluate its in vivo anti‐inflammatory and antioxidant activities. The ultraviolet–visible absorption spectrum of the synthesised Ag‐NPs showed an absorbance peak at 422. The average size of spherical nanoparticles was 24 nm as revealed by transmission electron microscopy. Fourier transform infra‐red spectroscopy analysis supported the presence of biological active compounds involved in the reduction of Ag ion and X‐ray diffraction confirmed the crystalline structure of the metallic Ag. The anti‐inflammatory and antioxidant activity of the Ag‐NPs was investigated against carrageenan‐induced paw oedema in mice. The levels of malondialdehyde (MDA) and antioxidant enzymes superoxide dismutase, catalase, glutathione peroxidase and inflammatory cytokines tumour necrosis factor (TNF‐α), interferon gamma and interleukin (IL)‐6, IL‐1β were assessed in this respect. The results demonstrated that anti‐inflammatory activity of the Ag‐NPs might be due to the ability of the nanoparticles to reduce IL‐1β, IL‐6 and TNF‐α. Moreover, reduction of antioxidant enzymes along with an increase in MDA level shows that the anti‐inflammatory activity of the synthesised Ag‐NPs by C. nobile is attributed to its ameliorating effect on the oxidative damage.Inspec keywords: silver, nanoparticles, nanofabrication, ultraviolet spectra, visible spectra, particle size, transmission electron microscopy, Fourier transform infrared spectra, X‐ray diffraction, crystal structure, enzymes, molecular biophysics, tumours, biomedical materials, nanomedicineOther keywords: Chamaemelum nobile extract, oxidative stress, mice paw, silver nanoparticles, antiinflammatory activity, antioxidant activity, ultraviolet‐visible absorption spectrum, spherical nanoparticle size, transmission electron microscopy, Fourier transform infrared spectroscopy, biological active compounds, X‐ray diffraction, crystalline structure, carrageenan‐induced paw oedema, malondialdehyde, antioxidant enzymes, superoxide dismutase, catalase, glutathione peroxidase, inflammatory cytokines, tumour necrosis factor, interferon gamma, interleukin, IL‐1β, IL‐6, TNF‐α, MDA level, Ag     

Antibacterial,anticancer and antioxidant potential of silver nanoparticles engineered using Trigonella foenum‐graecum seed extract

In this study, the authors report a simple and eco‐friendly method for the synthesis of silver nanoparticles (AgNPs) using Trigonella foenum‐graecum (TFG) seed extract. They explored several parameters dictating the biosynthesis of TFG‐AgNPs such as reaction time, temperature, concentration of AgNO₃, and TFG extract amount. Physicochemical characterisation of TFG‐AgNPs was done on dynamic light scattering (DLS), field emission electron microscopy, energy dispersive X‐ray spectroscopy, X‐ray diffraction and Fourier transform infrared spectroscopy. The size determination studies using DLS revealed of TFG‐AgNPs size between 95 and 110 nm. The antibacterial activity was studied against Escherichia coli, Proteus vulgaris, Pseudomonas aeruginosa and Staphylococcus aureus. The biosynthesised TFG‐AgNPs showed remarkable anticancer efficacy against skin cancer cell line, A431 and also exhibited significant antioxidant efficacy.Inspec keywords: antibacterial activity, cancer, biomedical materials, silver, nanofabrication, nanomedicine, nanoparticles, microorganisms, skin, cellular biophysics, biochemistry, light scattering, X‐ray chemical analysis, X‐ray diffraction, Fourier transform infrared spectra, particle sizeOther keywords: antibacterial potential, anticancer potential, antioxidant potential, silver nanoparticles, Trigonella foenum‐graecum seed extract, eco‐friendly method, biosynthesis, reaction time, AgNO₃ concentration, TFG extract amount, physicochemical characterisation, dynamic light scattering, field emission electron microscopy, energy dispersive X‐ray spectroscopy, X‐ray diffraction, Fourier transform infrared spectroscopy, size determination, TFG‐AgNPs size, Escherichia coli, Proteus vulgaris, Pseudomonas aeruginosa, Staphylococcus aureus, skin cancer cell line A431, Ag     

Green synthesis,characterisation and bioactivity of plant‐mediated silver nanoparticles using Decalepis hamiltonii root extract

Consistent search of plants for green synthesis of silver nanoparticles (SNPs) is an important arena in Nanomedicine. This study focuses on synthesis of SNPs using bioreduction of silver nitrate (AgNO₃) by aqueous root extract of Decalepis hamiltonii. The biosynthesis of SNPs was monitored by UV–vis analysis at absorbance maxima 432 nm. The fluorescence emission spectra of SNPs illustrated the broad emission peak 450–483 nm at different excitation wavelengths. The surface characteristics were studied by scanning electron microscope and atomic force microscopy, showed spherical shape of SNPs and dynamic light scattering analysis confirmed the average particle size 32.5 nm and the presence of metallic silver was confirmed by energy dispersive X‐ray. Face centred cubic structure with crystal size 33.3 nm was revealed by powder X‐ray diffraction. Fourier transform infrared spectroscopy indicated the biomolecules involved in the reduction mainly polyols and phenols present in root extracts were found to be responsible for the synthesis of SNPs. The stability and charge on SNPs were revealed by zeta potential analysis. In addition, on therapeutic forum, the synthesised SNPs elicit antioxidant and antimicrobial activity against Bacillus cereus, Bacillus licheniformis, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus.Inspec keywords: silver, nanoparticles, nanomedicine, antibacterial activity, biomedical materials, nanofabrication, particle size, microorganisms, ultraviolet spectra, visible spectra, fluorescence, scanning electron microscopy, atomic force microscopy, light scattering, X‐ray diffraction, X‐ray chemical analysis, Fourier transform infrared spectra, molecular biophysics, electrokinetic effectsOther keywords: phenols, zeta potential analysis, therapeutic forum, antioxidant activity, antimicrobial activity, Bacillus cereus, Bacillus licheniformis, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Ag, polyols, biomolecules, Fourier transform infrared spectroscopy, powder X‐ray diffraction, crystal size, face centred cubic structure, energy dispersive X‐ray analysis, metallic silver, particle size, dynamic light scattering analysis, spherical shape, atomic force microscopy, scanning electron microscopy, surface characteristics, excitation wavelengths, fluorescence emission spectra, UV‐visible analysis, biosynthesis, silver nitrate bioreduction, nanomedicine, Decalepis hamiltonii aqueous root extract, bioactivity, plant‐mediated silver nanoparticles, green synthesis     

Green synthesis of magnetically recoverable Fe3 O4 /HZSM‐5 and its Ag nanocomposite using Juglans regia L. leaf extract and their evaluation as catalysts for reduction of organic pollutants

In this work, an Fe₃ O₄ /HZSM‐5 nanocomposite was synthesised in the presence of Juglans regia L. leaf extract. Then, silver nanoparticles (Ag NPs) were immobilised on the surface of prepared magnetically recoverable HZSM‐5 using selected extract for reduction of Ag⁺ ions to Ag NPs and their stabilisation on the surface of the nanocomposite. The reduction of Ag⁺ ions occurs at room temperature within a few minutes. Characterisation of the prepared catalysts has been carried out using fourier transform infrared (FT‐IR), X‐ray diffraction, field‐emission scanning electron microscopy (FESEM), energy‐dispersive spectroscopy, Brunauer–Emmett–Teller method, and a vibrating sample magnetometer. According to the FESEM images of the nanocomposites, the average size of the Ag NPs on the Fe₃ O₄ /HZSM‐5 surface was >70 nm. The Ag/Fe₃ O₄ /HZSM‐5 nanocomposite was a highly active catalyst for the reduction of methyl orange and 4‐nitrophenol in aqueous medium. The utilisation of recycled catalyst for three times in the reduction process does not decrease its activity.Inspec keywords: silver, X‐ray chemical analysis, X‐ray diffraction, nanocomposites, reduction (chemical), nanofabrication, nanoparticles, transmission electron microscopy, catalysts, Fourier transform infrared spectra, iron compounds, field emission scanning electron microscopy, zeolites, magnetometry, particle sizeOther keywords: Ag‐Fe₃ O₄ , temperature 293 K to 298 K, green synthesis, catalyst material, 4‐nitrophenol reduction, methyl orange reduction, particle size, vibrating sample magnetometry, Brunauer–Emmett–Teller method, field‐emission scanning electron microscopy, X‐ray diffraction, FT‐IR spectroscopy, silver nanoparticles, Juglans regia L. leaf extract, organic pollutant reduction, magnetically recoverable nanocomposites, energy‐dispersive spectroscopy     

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     

Gundelia tournefortii L.: a natural source for the green synthesis of silver nanoparticles

The present study focused on the synthesis of spherical silver nanoparticles (Ag NPs) using Gundelia tournefortii L. aerial part extract. The plant extract could reduce silver ions into Ag NPs. To identify the compounds responsible for the reduction of silver ions, functional groups present in plant extract were investigated by Fourier transform infrared spectroscopy. Techniques used to characterise synthesised nanoparticles included field emission scanning electron microscopy, X‐ray diffraction and transmission electron microscopy. UV‐visible spectrophotometer showed the absorbance peak in the range of 400–450 nm. The Ag NPs showed antibacterial activities against both gram positive (Staphylococcus aureus and Bacillus Cereus) and gram negative (Salmonella typhimurium and Escherichia coli) microorganisms. The results confirmed that this protocol was simple, rapid, eco‐friendly, low‐priced and non‐toxic; therefore, it could be used as an alternative to conventional physical/chemical methods. Only 5 min were required for the conversion of silver ions into Ag NPs at room temperature, without the involvement of any hazardous chemical.Inspec keywords: nanoparticles, silver, nanofabrication, microorganisms, Fourier transform infrared spectra, transmission electron microscopy, ultraviolet spectra, visible spectraOther keywords: Ag, temperature 293 K to 298 K, chemical method, physical method, Salmonella typhimurium, Escherichia coli, gram negative microorganisms, Bacillus Cereus, Staphylococcus aureus, gram positive microorganisms, antibacterial activities, absorbance peak, UV‐visible spectrophotometer, transmission electron microscopy, X‐ray diffraction, field emission scanning electron microscopy, Fourier transform infrared spectroscopy, functional groups, plant extract, Gundelia tournefortii L. aerial part extract, spherical silver nanoparticle synthesis, silver nanoparticle green synthesis, natural source     

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     

Solvothermal‐assisted green synthesis of hybrid Chi‐Fe3 O4 nanocomposites: a potential antibacterial and antibiofilm material

In this present study, a hybrid Chi‐Fe₃ O₄ was prepared, characterised and evaluated for its antibacterial and antibiofilm potential against Staphylococcus aureus and Staphylococcus marcescens bacterial pathogens. Intense peak around 260 nm in the ultraviolet–visible spectrum specify the formation of magnetite nanoparticles. Spherical‐shaped particles with less agglomeration and particle size distribution of 3.78–46.40 nm were observed using transmission electron microscopy analysis and strong interaction of chitosan with the surface of magnetite nanoparticles was studied using field emission scanning microscopy (FESEM). X‐ray diffraction analysis exhibited the polycrystalline and spinel structure configuration of the nanocomposite. Presence of Fe and O, C and Cl elements were confirmed using energy dispersive X‐ray microanalysis. Fourier transform infrared spectroscopic analysis showed the reduction and formation of Chi‐Fe₃ O₄ nanocomposite. The antibacterial activity by deformation of the bacterial cell walls on treatment with Chi‐Fe₃ O₄ nanocomposite and its interaction was visualised using FESEM and the antibiofilm activity was determined using antibiofilm assay. In conclusion, this present study shows the green synthesis of Chi‐Fe₃ O₄ nanocomposite and evaluation of its antibacterial and antibiofilm potential, proving its significance in medical and biological applicationsInspec keywords: visible spectra, particle size, magnetic particles, nanocomposites, nanoparticles, X‐ray diffraction, nanofabrication, transmission electron microscopy, X‐ray chemical analysis, nanomagnetics, microorganisms, antibacterial activity, iron compounds, ultraviolet spectra, biomedical materials, field emission scanning electron microscopy, Fourier transform infrared spectra, filled polymers, crystal growth from solution, polymer structureOther keywords: potential antibacterial material, antibiofilm potential, magnetite nanoparticles, solvothermal‐assisted green synthesis, hybrid Chi‐Fe₃ O₄ nanocomposites, staphylococcus aureus, staphylococcus marcescens, bacterial pathogens, ultraviolet–visible spectrum, spherical‐shaped particles, particle size, transmission electron microscopy, FESEM, field emission scanning electron microscopy, X‐ray diffraction, spinel structure, polycrystalline structure, energy dispersive X‐ray microanalysis, Fourier transform infrared spectroscopic analysis, deformation, bacterial cell walls, Fe₃ O₄      

Catalytic reduction of 2,4‐dinitrophenylhydrazine by cuttlebone supported Pd NPs prepared using Conium maculatum leaf extract

A facile and green process to synthesise cuttlebone supported palladium nanoparticles (Pd NPs/cuttlebone) is reported using Conium maculatum leaf extract and in the absence of chemical solvents and hazardous materials. The antioxidant content of the C. maculatum leaf extract played a significant role in converting Pd²⁺ ions to Pd NPs. Various techniques were used for the characterisation of the Pd NPs/cuttlebone such as field‐emission scanning electron microscopy, X‐ray diffraction, energy dispersive X‐ray spectroscopy, Fourier transform infrared and ultraviolet–visible spectroscopy. This Pd NPs/cuttlebone showed excellent catalytic activity in the reduction of 2,4‐dinitrophenylhydrazine to 2,4‐diaminophenylhydrazine by sodium borohydride as the source of hydrogen at ambient condition. The catalyst could be separated and recycled up to five cycles with no loss of its activity.Inspec keywords: catalysis, catalysts, chemical engineering, palladium, nanoparticles, field emission electron microscopy, scanning electron microscopy, X‐ray diffraction, X‐ray chemical analysis, sodium compounds, ultraviolet spectroscopy, visible spectroscopyOther keywords: catalytic reduction, 2,4‐dinitrophenylhydrazine, cuttlebone, Conium maculatum leaf extract, green process, palladium nanoparticles, antioxidant content, field‐emission scanning electron microscopy, X‐ray diffraction, energy dispersive X‐ray spectroscopy, Fourier transform infrared, ultraviolet–visible spectroscopy, 2,4‐diaminophenylhydrazine, sodium borohydride