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     

Synthesis of extracellular gold nanoparticles using Cupriavidus metallidurans CH34 cells

In this study, spontaneous synthesis of a gold (Au) colloid using cells of Cupriavidus metallidurans CH34 is reported, and compared with results obtained using cells of the model bacterium Escherichia coli MG1655. To investigate the synthesis mechanism, bacterial biomass and secretomes from both strains were incubated with Au(III) ions. Only CH34 cells were capable of producing extracellular dispersions of Au nanoparticles (NPs). Transmission electron microscopy images showed that AuNPs morphology was dominated by triangular and decahedral nanostructures. Energy dispersive X‐ray spectroscopy and Fourier transform infrared spectra showed the presence of sulphur and vibrations associated to proteins. Average AuNPs diameter was obtained by dynamic light‐scattering measurements (DLS), NP tracking analysis measurements and analysis of electron microscopy images. Moreover, DLS measurements showed that the biogenic colloid was stable after exposure to ultrasound, high ionic strength and extreme pH conditions. The biogenic AuNPs produced by strain CH34 did not show antibacterial activity, in contrast to biogenic silver NPs. Comparative bioinformatic analysis of genomes from strain CH34 and strain MG1655 showed potential CH34 proteins that may be electron donors during reduction of Au(III) ions. On the basis of these results, a mechanism for the extracellular Au reduction by strain CH34 is proposed.Inspec keywords: gold, nanoparticles, cellular biophysics, X‐ray diffraction, transmission electron microscopy, X‐ray chemical analysis, Fourier transform infrared spectra, proteins, molecular biophysics, light scattering, colloids, pH, genomics, nanomedicine, antibacterial activity, biomedical materials, nanofabrication, biochemistryOther keywords: extracellular gold nanoparticles, Cupriavidus metallidurans CH34 cells, gold colloid, bacterial biomass, bacterial secretomes, Au(III) ions, extracellular dispersions, powder X‐ray diffraction, face‐centred cubic phase, transmission electron microscopy, AuNP morphology, triangular nanostructures, decahedral nanostructures, energy dispersive X‐ray spectroscopy, Fourier transform infrared spectra, proteins, dynamic light‐scattering measurements, DLS measurements, NP tracking analysis, electron microscopy images, biogenic colloid, high ionic strength, pH conditions, bioinformatic analysis, genomes, Au     

Green synthesis of CuO nanoparticles loaded on the seashell surface using Rumex crispus seeds extract and its catalytic applications for reduction of dyes

In this study, CuO nanoparticles supported on the seashell (CuO NPs/seashell) was prepared using Rumex crispus seeds extract as a chelating and capping agent. The prepared nanocomposite was characterised by Fourier transform infrared spectroscopy, X‐ray diffraction, field emission scanning electron microscopy, energy‐dispersive X‐ray spectroscopy and transmission electron microscopy. The particle size of CuO NPs on the seashell sheets was in the range of 8–60 nm. Catalytic ability of CuO NPs/seashell was investigated for the reduction of 4‐nitrophenol (4‐NP) and Congo red (CR). It was observed that catalyst can be easily recovered and reused several times without any significant loss of catalytic efficiency.Inspec keywords: nanocomposites, nanoparticles, catalysis, dyes, Fourier transform infrared spectra, X‐ray diffraction, field emission electron microscopy, scanning electron microscopy, X‐ray chemical analysis, transmission electron microscopy, particle size, copper compoundsOther keywords: CuO, size 8 nm to 60 nm, Congo red, 4‐nitrophenol, particle size, transmission electron microscopy, energy dispersive X‐ray spectroscopy, field emission scanning electron microscopy, X‐ray diffraction, Fourier transform infrared spectroscopy, nanocomposite, capping agent, chelating agent, dye reduction, catalytic application, Rumex crispus seeds extract, seashell surface, nanoparticles, green synthesis     

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     

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     

Peanut skin extract mediated synthesis of gold nanoparticles,silver nanoparticles and gold–silver bionanocomposites for electrochemical Sudan IV sensing

Sustainable methods are needed for rapid and efficient detection of environmental and food pollutants. The Sudan group of dyes has been used extensively as adulterants in food and also are found to be polluting the soil and water bodies. There have been several methods for detection of Sudan dyes, but most of them are not practical enough for common use. In this study, the electrochemical detection efficiency and stability of gold nanoparticle (AuNPs), silver NPs and Au–Ag bionanocomposites, synthesised by peanut skin extract, modified glassy carbon electrode has been investigated. The synthesised nanomaterial samples were characterised, for their quality and quantity, using ultra–visible spectroscopy, inductive coupled plasma mass spectrophotometer, Fourier transform infrared spectroscopy, energy‐dispersive X‐ray spectroscopy, high‐resolution transmission electron microscope and field emission scanning electron microscope. The nanomaterial hybrid electrodes showed great efficiency and stability in the detection of Sudan IV compared with the other previous electrodes. The peak current of the Sudan IV oxidation and reduction was found to be proportional to its concentration, in the range of 10–80 µM, with a detection limit of 4 µM. The hybrid electrodes showed 90% stability in detection for 20 cycles.Inspec keywords: gold, silver, nanoparticles, nanocomposites, biomedical materials, electrochemical sensors, dyes, nanofabrication, ultraviolet spectra, visible spectra, spectrophotometry, Fourier transform infrared spectra, X‐ray chemical analysis, transmission electron microscopy, scanning electron microscopy, field emission electron microscopyOther keywords: peanut skin extract mediated synthesis, gold nanoparticles, silver nanoparticles, gold–silver bionanocomposites, electrochemical Sudan IV sensing, electrochemical detection efficiency, modified glassy carbon electrode, ultra–visible spectroscopy, inductive coupled plasma mass spectrophotometer, Fourier transform infrared spectroscopy, energy‐dispersive X‐ray spectroscopy, high‐resolution transmission electron microscope, field emission scanning electron microscope, oxidation, reduction, detection limit, Au, Ag, Au‐Ag     

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     

Alkaline treatment effect on the properties of in‐situ synthesised ZnO nanoparticles on cotton fabric

In this study, an in‐situ approach was used to synthesise zinc oxide nanoparticles on the surface of cotton fabric. The effect of alkaline pre‐ and after‐treatment and Zn²⁺ concentration was studied on the morphological, structural, thermal, photocatalytic, and antibacterial properties of loaded cotton fabrics. Scanning electron microscopy, energy dispersive X‐ray spectroscopy, X‐ray diffractometer, thermogravimetric analysis, and attenuated total reflection Fourier transform infrared spectrometer were used to characterise the properties of loaded cotton fabrics. Alkaline after‐treatment of cotton fabric presented more dispersed zinc oxide nanoparticles, and an increase in Zn²⁺ concentration led to form agglomerated nanoparticles on the surface of cotton fibres. The loaded cotton fabrics with zinc oxide nanoparticles presented an inhibition zone against Staphylococcus aureus and Escherichia coli. In addition, the stain of methylene blue on the surface of loaded samples was degraded after irradiated under visible light.Inspec keywords: nanofabrication, zinc compounds, II‐VI semiconductors, nanoparticles, nanomedicine, antibacterial activity, catalysis, photochemistry, cotton fabrics, scanning electron microscopy, X‐ray chemical analysis, X‐ray diffraction, thermal analysis, attenuated total reflection, Fourier transform infrared spectroscopy, microorganisms, materials preparationOther keywords: alkaline treatment effect, in‐situ synthesised ZnO nanoparticles, alkaline pretreatment, alkaline after‐treatment, Zn²⁺ concentration, morphological property, structural property, thermal property, photocatalytic property, antibacterial property, loaded cotton fabrics, scanning electron microscopy, energy dispersive X‐ray spectroscopy, X‐ray diffractometer, thermogravimetric analysis, attenuated total reflection Fourier transform infrared spectrometer, agglomerated nanoparticles, zinc oxide nanoparticles, inhibition zone, Staphylococcus aureus, Escherichia coli, methylene blue, visible light, ZnO     

Synthesis,characterisation and bactericidal effect of ZnO nanoparticles via chemical and bio‐assisted (Silybum marianum in vitro plantlets and callus extract) methods: a comparative study

Currently, the evolution of green chemistry in the synthesis of nanoparticles (NPs) with the usage of plants has captivated a great response. In this study, in vitro plantlets and callus of Silybum marianum were exploited as a stabilising agent for the synthesis of zinc oxide (ZnO) NPs using zinc acetate and sodium hydroxide as a substitute for chemical method. The contemporary investigation defines the synthesis of ZnO NPs prepared by chemical and bio‐extract‐assisted methods. Characterisation techniques such as X‐ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy and energy dispersive X‐ray were used to confirm the synthesis. Although chemical and bio‐assisted methods are suitable choices for NPs synthesis, the bio‐assisted green assembly is advantageous due to superior stability. Moreover, this report describes the antibacterial activity of the synthesised NPs against standard strains of Klebsiella pneumonia and Bacillus subtilis.Inspec keywords: zinc compounds, II‐VI semiconductors, wide band gap semiconductors, nanoparticles, nanofabrication, semiconductor growth, antibacterial activity, X‐ray diffraction, X‐ray chemical analysis, scanning electron microscopy, Fourier transform infrared spectra, nanobiotechnologyOther keywords: chemical methods, bio‐assisted methods, Silybum marianum in vitro plantlets methods, Silybum marianum in vitro callus extract methods, green chemistry, zinc oxide nanoparticles, sodium hydroxide, zinc acetate, X‐ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, energy dispersive X‐ray analysis, bio‐assisted green assembly, antibacterial activity, Klebsiella pneumonia, Bacillus subtilis, ZnO     

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 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     

Green synthesis of the Ag/ZnO nanocomposite using Valeriana officinalis L. root extract: application as a reusable catalyst for the reduction of organic dyes in a very short time

A facile and green synthesis of the Ag/ZnO nanocomposite by extract of Valeriana officinalis L. root in the absence of any stabiliser or surfactant has been reported in this work. The green synthesised Ag/ZnO nanocomposite was characterised by Field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy dispersive X‐ray spectroscopy (EDS), elemental mapping, Fourier‐Transform infrared (FT‐IR), X‐ray diffraction analysis (XRD) and UV‐Vis spectroscopy. According to SEM and TEM images, the Ag and ZnO particles are spherical with diameters of less than 20 and 40–50 nm, respectively. The Ag NPs/ZnO nanocomposite proved to be an effective catalyst in the reduction of various dyes including methyl orange (MO), Congo red (CR) and methylene blue (MB) in the presence of NaBH₄ in aqueous media at ambient temperature. A maximum degradation (100%) of dyes was performed using Ag/ZnO nanocomposite. The extraordinary performance of the prepared Ag/ZnO nanocomposite is attributed to the synergetic effect induced by both ZnO and Ag NPs in the catalytic degradation of organic dyes. The catalyst could be reused and recovered several times with no significant loss of catalytic activity.Inspec keywords: nanocomposites, silver, zinc compounds, II‐VI semiconductors, nanofabrication, catalysts, reduction (chemical), field emission electron microscopy, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectra, ultraviolet spectra, visible spectra, X‐ray diffraction, surface morphology, nanoparticles, dyesOther keywords: green synthesis, nanocomposite, Valeriana officinalis L. root extract, reusable catalyst, reduction, organic dyes, surfactant, field emission scanning electron microscopy, transmission electron microscopy, energy dispersive X‐ray spectroscopy, elemental mapping, Fourier‐transform infrared spectroscopy, X‐ray diffraction analysis, surface morphology, nanoparticles, methyl orange, congo red, methylene blue, UV–Vis spectroscopy, size 40 nm to 50 nm, wavelength 493 nm, wavelength 465 nm, wavelength 663 nm, Ag‐ZnO     

Green synthesis of copper oxide nanoparticles using aqueous extract of Convolvulus percicus L. as reusable catalysts in cross‐ coupling reactions and their antibacterial activity

CuO nanoparticles (NPs) were prepared by Convolvulus percicus leaves extract as a reducing and stabilising agent. The green synthesised copper oxide NPs was characterised by transmission electron microscope, energy dispersive X‐Ray spectroscopy, X‐ray diffraction, Fourier transform infrared and ultraviolet‐visible analysis. The activities of the CuO NPs as catalyst were tested in the formation of C‐N and C‐O bonds. The N ‐arylated and O ‐arylated products of amides, N‐H heterocycles and phenols were obtained in excellent yields. Furthermore, the separation and recovery of copper oxide NPs was very simple, effective and economical. The recovered catalyst can be reused several times without significant loss of its catalytic activity. Moreover, the antibacterial activity of these NPs was tested against two human pathogenic microbes and showed significant antimicrobial activity against these pathogenic bacteria.Inspec keywords: copper compounds, nanoparticles, nanomedicine, antibacterial activity, biomedical materials, nanofabrication, microorganisms, catalysts, transmission electron microscopy, X‐ray chemical analysis, X‐ray diffraction, Fourier transform spectra, infrared spectra, ultraviolet spectra, visible spectra, catalysisOther keywords: green synthesis, copper oxide nanoparticles, Convolvulus percicus L. aqueous extract, reusable catalysts, cross‐coupling reactions, antibacterial activity, reducing agent, stabilising agent, transmission electron microscope, energy dispersive X‐ray spectroscopy, X‐ray diffraction, Fourier transform infrared spectra, ultraviolet‐visible spectra, C‐N bonds, C‐O bonds, N‐arylated products, O‐arylated products, amides, N‐H heterocycles, phenols, catalytic activity, human pathogenic microbes, antimicrobial activity, CuO     

Phyto‐mediated synthesis,biological and catalytic activity studies of gold nanoparticles

In the present study, a phyto‐mediated synthesis of gold nanoparticles (AuNPs) using an isoflavone, Dalspinosin (5,7‐dihydroxy‐6,3′,4′‐trimethoxy isoflavone) isolated from the alcoholic extract of roots of Dalbergia coromandeliana is reported. It is observed that Dalspinosin itself acts both as a reducing and a capping agent in the synthesis of the nanoparticles (NPs). An ultraviolet–visible (UV–Vis) spectral study showed a surface plasmon resonance band at 526 nm confirming the formation of AuNPs. The NPs formed were characterised by UV–Vis spectroscopy, Fourier transform‐infrared spectroscopy, X‐ray diffraction (XRD), high‐resolution transmission electron microscopy (HR‐TEM) with energy‐dispersive x‐ray spectroscopy (EDX) and dynamic light scattering. HR‐TEM analysis showed the synthesised AuNPs were spherical in shape with a size of 7.5 nm. The AuNPs were found to be stable for seven months when tested by in vitro methods showed good antioxidant and anti‐inflammatory activities. They also showed moderate anti‐microbial activities when tested against Gram positive (Staphylococcus aureus and Streptococcus sp), Gram negative bacterial strains (Klebsiella pneumonia and Klebsiella terrigena) and fungal strain (Candida glabrata). The biosynthesised AuNPs showed significant catalytic activity in the reduction of methylene blue with NaBH₄ to leucomethylene blue.Inspec keywords: biomedical materials, catalysis, Fourier transform infrared spectra, gold, light scattering, microorganisms, nanomedicine, nanoparticles, spectrochemical analysis, surface plasmon resonance, transmission electron microscopy, ultraviolet spectra, visible spectra, X‐ray chemical analysis, X‐ray diffractionOther keywords: phyto‐mediated synthesis, biological activity studies, catalytic activity studies, dalspinosin (5,7‐dihydroxy‐6,3′,4′‐trimethoxy isoflavone), alcoholic extract, roots, Dalbergia coromandeliana, ultraviolet‐visible spectral study, surface plasmon resonance band, UV‐Vis spectroscopy, Fourier transform‐infrared spectroscopy, X‐ray diffraction, high‐resolution transmission electron microscopy, EDX analysis, dynamic light scattering, HR‐TEM analysis, antioxidant activities, antiinflammatory activities, antimicrobial activities, Gram positive bacterial strains, Staphylococcus aureus, Streptococcus sp, Gram negative bacterial strains, wavelength 526 nm, size 7.5 nm, time 7 month, Au     

Antibacterial and anticancer activity of biosynthesised CuO nanoparticles

The present investigation aims for the synthesis of copper oxide nanoparticles (CuO NPs) using Nilgirianthus ciliatus plant extract. The obtained CuO NPs were characterised by X‐ray diffraction, Fourier transform infrared spectrum, ultraviolet–visible spectroscopy, photoluminescence, scanning electron microscopy and transmission electron microscopy analysis. Significant bacterial activity was manifested by CuO nanoparticles against both Gram‐positive (Staphylococcus aureus and Staphylococcus mutans) and Gram‐negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. The synthesised CuO NPs have good cytotoxicity against both human breast cancer cell line (MCF‐7) and lung cancer cell line (A549) with minimum cytotoxic effect on normal L929 (fibroblast) cell lines.Inspec keywords: microorganisms, ultraviolet spectra, nanomedicine, transmission electron microscopy, visible spectra, cellular biophysics, antibacterial activity, nanoparticles, X‐ray diffraction, lung, copper compounds, cancer, toxicology, biomedical materials, scanning electron microscopy, photoluminescence, Fourier transform infrared spectraOther keywords: antibacterial activity, anticancer activity, biosynthesised CuO nanoparticles, copper oxide nanoparticles, Nilgirianthus ciliatus plant, X‐ray diffraction, infrared spectrum, ultraviolet–visible spectroscopy, transmission electron microscopy analysis, bacterial activity, Gram‐negative bacteria, synthesised CuO NPs, human breast cancer cell line, Staphylococcus aureus, Staphylococcus mutans, CuO     

Biosynthesis of silver and gold nanoparticles using Trichoderma atroviride for the biological control of Phomopsis canker disease in tea plants

The biological way of metallic nanoparticles production using ecofriendly biocontrol agents are largely used to control many plant pathogenic microorganisms in agriculture. Hence, an attempt was made to evaluate the potential of suppressive activity of nanoparticles produced by an indigenous isolate, Trichoderma atroviride against a tea pathogenic fungus namely Phomopsis theae. The presence of biosynthesised nanoparticles was primarily confirmed through ultraviolet–visible spectroscopy analysis and was characterised using X‐ray diffraction and scanning electron microscopy‐energy dispersive X‐ray analysis to delineate the size, shape and nature of particles. Further, Fourier transform infrared analysis revealed the functional biomolecules responsible for capping and stabilisation of nanoparticles. In addition, culture filtrate containing nanoparticles was subjected to invitro antifungal studies which revealed a considerable suppression on the growth of P. theae. The biosynthesised nanoparticles were found to be active even after 3 months which established and confirmed the stability. Finally, field experiments conducted with soil application and wound dressing of nanoparticles exhibited a significant reduction in canker size when plants treated with gold followed by silver nanoparticles. Similarly, improvement in leaf yield was noted in response to these treatments. The above study confirmed the efficacy of metallic nanoparticles in management of stem disease in tea plantation.Inspec keywords: diseases, gold, silver, nanoparticles, nanobiotechnology, nanofabrication, particle size, X‐ray diffraction, scanning electron microscopy, X‐ray chemical analysis, ultraviolet spectra, visible spectra, microorganisms, Fourier transform infrared spectra, molecular biophysics, antibacterial activityOther keywords: biosynthesis, silver nanoparticles, gold nanoparticles, Trichoderma atroviride, biological control, Phomopsis canker disease, tea plants, metallic nanoparticles, ecofriendly biocontrol agents, plant pathogenic microorganisms, agriculture, indigenous isolate, tea pathogenic fungus, Phomopsis theae, ultraviolet‐visible spectroscopy, X‐ray diffraction, scanning electron microscopy, energy dispersive X‐ray analysis, particle size, particle shape, Fourier transform infrared analysis, functional biomolecules, invitro antifungal study, P. theae growth, soil application, wound dressing, stem disease, Au, Ag     

Biofabrication of gold nanoparticles using marine endophytic fungus – Penicillium citrinum

Nanotechnology is one of the promising fields of research and generating new avenues and applications in medicine. Recently, marine floras such as, marine endophytes are gaining the attention of many researchers due to the myriad of bioactive molecules that they possess. In addition, they find applications in many pharmaceutical and cosmetic industries. In this study, they have studied the green synthesis of gold nanoparticles (AuNPs) from Penicillium citrinum (P. citrinum) and its antioxidant activity. P. citrinum was isolated from brown algae. The identity of the fungus was established by comparing its 18S rDNA sequence. AuNPs were synthesised using P. citrinum and were characterised by UV–visible spectrophotometer (UV–vis), field emission scanning electron microscope (FESEM), X‐ray diffraction, Fourier transform infrared spectroscopy and dynamic light scattering (DLS). AuNPs were tested for free radical scavenging activity by 1,1‐diphenyl‐2‐picrylhydrazyl method. The particle sizes of AuNps were determined by FESEM and DLS. The reduction of gold metal ion was confirmed from the UV–vis spectrum. AuNPs showed significant antioxidant potential and the activity was comparable to the standard ascorbic acid. Further, in vitro and in vivo studies on these AuNPs will help in developing an alternative, cost‐effective and acceptable drug for various ailments.Inspec keywords: microorganisms, nanoparticles, gold, nanofabrication, particle size, nanobiotechnology, DNA, molecular biophysics, molecular configurations, ultraviolet spectra, visible spectra, field emission electron microscopy, scanning electron microscopy, X‐ray diffraction, Fourier transform infrared spectra, light scattering, free radical reactions, biochemistryOther keywords: biofabrication, gold nanoparticles, marine endophytic fungi, Penicillium citrinum, nanotechnology, medicine applications, marine floras, marine endophytes, bioactive molecules, pharmaceutical industries, cosmetic industries, antioxidant activity, brown algae, 18S rDNA sequence, UV‐visible spectrophotometer, field emission scanning electron microscope, FESEM, X‐ray diffraction, Fourier transform infrared spectroscopy, dynamic light scattering, free radical scavenging activity, 1,1‐diphenyl‐2‐picrylhydrazyl method, particle sizes, gold metal ion reduction, antioxidant potential, standard ascorbic acid, drug, ailments, Au     

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     

Extracellular synthesis gold nanotriangles using biomass of Streptomyces microflavus

Applications of nanotechnology and nano‐science have ever‐expanding breakthroughs in medicine, agriculture and industries in recent years; therefore, synthesis of metals nanoparticle (NP) has special significance. Synthesis of NPs by chemical methods are long, costly and hazardous for environment so biosynthesis has been developing interest for researchers. In this regard, the extracellular biosynthesis of gold nanotriangles (AuNTs) performed by use of the soil Streptomycetes. Streptomycetes isolated from rice fields of Guilan Province, Iran, showed biosynthetic activity for producing AuNTs via in vitro experiments. Among all 15 Streptomyces spp. isolates, isolate No. 5 showed high biosynthesis activity. To determine the bacterium taxonomical identity at genus level, its colonies characterised morphologically by use of scanning electron microscope. The polymerase chain reaction (PCR) molecular analysis of active isolate represented its identity partially. In this regard, 16S rRNA gene of the isolate was amplified using universal bacterial primers FD1 and RP2. The PCR products were purified and sequenced. Sequence analysis of 16S rDNA was then conducted using National Center for Biotechnology Information Basic Local Alignment Search Tool method. The AuNTs obtained were characterised by ultraviolet–visible spectroscopy, atomic force microscopy, transmission electron microscopy and energy dispersive X‐ray spectroscopy, Fourier transform infrared spectroscopy (FTIR) and X‐ray diffraction spectroscopy analyses. The authors results indicated that Streptomyces microflavus isolate 5 bio‐synthesises extracellular AuNTs in the range of 10–100 nm. Synthesised SNPs size ranged from 10 to 100 nm. In comparison with chemical methods for synthesis of metal NPs, the biosynthesis of AuNTs by Streptomyces source is a fast, simple and eco‐friendly method. The isolate is a good candidate for further investigations to optimise its production efficacy for further industrial goals in biosynthesis of AuNTs.Inspec keywords: microorganisms, cellular biophysics, gold, nanobiotechnology, renewable materials, DNA, proteins, nanoparticles, scanning electron microscopy, genetics, biochemistry, enzymes, molecular configurations, bioinformatics, ultraviolet spectra, visible spectra, atomic force microscopy, transmission electron microscopy, X‐ray chemical analysis, Fourier transform spectra, infrared spectra, X‐ray diffraction, biological techniques, nanofabricationOther keywords: extracellular synthesis, biomass, Streptomyces microflavus, nanotechnology, nanoscience, biosynthesis, gold nanotriangles, Streptomycetes spp. isolates, rice fields, Guilan Province, Iran, bacterium taxonomical identity, genus level, scanning electron microscope, polymerase chain reaction, PCR, molecular analysis, 16S rRNA gene, universal bacterial primer FD1, universal bacterial primer RP2, sequence analysis, National Center for Biotechnology Information, ultraviolet‐visible spectroscopy, atomic force microscopy, transmission electron microscopy, energy dispersive X‐ray spectroscopy, Fourier transform infrared spectroscopy, FTIR, X‐ray diffraction spectroscopy, Basic Local Alignment Search Tool method, size 10 nm to 100 nm, Au     

Preparation of silver iodide nanoparticles using laser ablation in liquid for antibacterial applications

In this study, the authors reported the first synthesis process of silver iodide (AgI) nanoparticles (NPs) by pulsed laser ablation of the AgI target in deionised distilled water. The optical and structural properties of AgI NPs were investigated by using UV–vis absorption, X‐ray diffraction, scanning electron microscope (SEM), energy dispersive X‐ray, Fourier transform infrared spectroscopy, and transmission electron microscope (TEM). The optical data showed the presence of plasmon peak at 434 nm and the optical bandgap was found to be 2.6 eV at room temperature. SEM results confirm the agglomeration and aggregation of synthesised AgI NPs. TEM investigation showed that AgI NPs have a spherical shape and the average particle size was around 20 nm. The particle size distribution was the Gaussian type. The results showed that the synthesised AgI NPs have antibacterial activities against both bacterial strains and the activities were more potent against gram‐negative bacteria.Inspec keywords: antibacterial activity, nanoparticles, X‐ray chemical analysis, particle size, transmission electron microscopy, X‐ray diffraction, nanofabrication, scanning electron microscopy, visible spectra, ultraviolet spectra, silver compounds, pulsed laser deposition, Fourier transform infrared spectra, optical constants, energy gap, aggregationOther keywords: synthesis process, pulsed laser ablation, AgI target, deionised distilled water, optical properties, structural properties, UV–vis absorption, X‐ray diffraction, transmission electron microscope, optical data, optical bandgap, antibacterial activities, silver iodide nanoparticles, energy dispersive X‐ray analysis, SEM, wavelength 434.0 nm, temperature 293 K to 298 K, AgI