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     

Synthesis,characterisation and potential biomedical applications of magnetic core–shell structures: carbon‐, dextran‐, SiO2 ‐ and ZnO‐coated Fe3 O4 nanoparticles

Due to the strong effect of nanoparticles'' size and surface properties on cellular uptake and bio‐distribution, the selection of coating material for magnetic core–shell nanoparticles (CSNPs) is very important. In this study, the effects of four different biocompatible coating materials on the physical properties of Fe₃ O₄ (magnetite) nanoparticles (NPs) for different biomedical applications are investigated and compared. In this regard, magnetite NPs are prepared by a simple co‐precipitation method. Then, CSNPs including Fe₃ O₄ as a core and carbon, dextran, ZnO (zincite) and SiO₂ (silica) as different shells are synthesised using simple one‐ or two‐step methods. A comprehensive study is carried out on the prepared samples using X‐ray diffraction, vibrating sample magnetometry, transmission electron microscopy and Fourier transform infrared spectroscopy analyses. According to the authors'' findings, it is suggested that carbon‐ and dextran‐coated magnetite NPs with high M _s have great potential in the application of magnetic resonance imaging contrast agents. Moreover, silica‐coated magnetite NPs with high coercivity are potentially suitable candidates for hyperthermia and ZnO‐coated Fe₃ O₄ is potentially suitable for photothermal therapy.Inspec keywords: iron compounds, carbon, silicon compounds, zinc compounds, nanomedicine, biomedical materials, nanofabrication, nanoparticles, magnetic particles, coatings, X‐ray diffraction, magnetometry, transmission electron microscopy, Fourier transform spectra, infrared spectra, biomedical MRI, hyperthermia, radiation therapyOther keywords: biomedical applications, magnetic core‐shell nanoparticles, CSNP, cellular uptake, biodistribution, coating material, biocompatible coating materials, co‐precipitation, dextran, zincite, silica, X‐ray diffraction, vibrating sample magnetometry, transmission electron microscopy, Fourier transform infrared spectroscopy, magnetic resonance imaging contrast agents, hyperthermia, photothermal therapy, SiO₂ ‐Fe₃ O₄ , ZnO‐Fe₃ O₄      

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     

Functionalisation of Fe3 O4 nanoparticles by 2‐((pyrazol‐4‐yl) methylene) hydrazinecarbothioamide enhances the apoptosis of human breast cancer MCF‐7 cells

Cancer is a major cause of death. Thus, the incidence and mortality rate of cancer is globally important. Regarding vast problems caused by chemotherapy drugs, efforts have progressed to find new anti‐cancer drugs. Pyrazole derivatives are known as components with anti‐cancer properties. In here, Fe₃ O₄ nanoparticles were first functionalized with (3‐chloropropyl) trimethoxysilane, then 2‐((pyrazol‐4‐yl) methylene) hydrazinecarbothioamide (P) was anchored on the surface of magnetic nanoparticles (PL). The synthesized nano‐compounds were characterized using Fourier transform infrared spectroscopy, X‐ray diffraction, scanning electron microscopy, Zeta potential, dynamic light scattering, and energy‐dispersive x‐ray spectrometry analyses. The cytotoxicity effect was evaluated using MTT assay, apoptosis test by Flow cytometry, cell cycle analysis, Caspase‐3 activity assay and Hoechst staining on MCF‐7 cell line. The high toxicity for tumor cells and low toxicity on normal cells (MCF10A) was considered as an important feature (selectivity index, 10.9). Based on results, the IC50 for P and PL compounds were 157.80 and 131.84 μM/ml respectively. Moreover, apoptosis inducing, nuclear fragmentation, Caspase 3 activity and induction of cell rest in sub‐G1 and S phases, were also observed. The inhibitory effect of PL was significantly higher than P, which could be due to the high penetrability of Fe₃ O₄ nanoparticles.Inspec keywords: magnetic particles, drugs, nanomedicine, biochemistry, cancer, light scattering, scanning electron microscopy, molecular biophysics, iron compounds, electrokinetic effects, nanofabrication, tumours, X‐ray diffraction, cellular biophysics, nanoparticles, biomedical materials, toxicology, nanomagnetics, Fourier transform infrared spectra, enzymes, X‐ray chemical analysisOther keywords: anticancer properties, Fe₃ O₄ magnetic nanoparticles, (3‐chloropropyl) trimethoxysilane, energy‐dispersive X‐ray spectrometry, cell cycle analysis, MCF‐7 cell line, tumour cells, human breast cancer MCF‐7 cells, mortality rate, pyrazole derivatives, 2‐((pyrazol‐4‐yl) methylene) hydrazinecarbothioamide, chemotherapy drugs, heterocyclic components, nanocompounds, X‐ray diffraction, scanning electron microscopy, Zeta potential, dynamic light scattering, cytotoxicity effect, MTT assay, apoptosis test, caspase‐3 activity assay, Hoechst staining, MCF10A nontumourigenic cells, cell rest induction, nuclear fragmentation, Fe₃ O₄      

Antibacterial activity of carbon nanoparticles isolated from chimney soot

Carbon nanoparticles (CNPs) are isolated from chimney soot and characterised by various tools such as X‐ray diffraction, scanning electron microscopy, transmission electron microscopy and ultraviolet–visible spectroscopy. The X‐ray diffraction studies confirm the presence of C₆₀ nanoparticles in the isolated sample. The thermal properties of the prepared CNPs are recorded using thermogravimetric analysis and differential thermal analysis. The analysis of the antibacterial activity of the synthesised CNPs against selected Gram‐positive and Gram‐negative bacterial strains is also investigated. The systematic study confirms that CNPs collected from chimney soot exhibit good antibacterial potency against Staphylococcus aureus, Streptococcus pyogenes, Klebsiella pneumoniae, and Proteus mirabilis.Inspec keywords: ultraviolet spectra, scanning electron microscopy, visible spectra, differential thermal analysis, thermal analysis, antibacterial activity, nanoparticles, X‐ray diffraction, nanofabrication, transmission electron microscopy, carbonOther keywords: chimney soot, transmission electron microscopy, ultraviolet–visible spectroscopy, thermal properties, thermogravimetric analysis, differential thermal analysis, antibacterial activity, carbon nanoparticles, X‐ray diffraction study, gram‐positive bacterial strains, gram‐negative bacterial strains, antibacterial potency, scanning electron microscopy, C₆₀      

Catalytic hydrolysis of cellobiose using different acid‐functionalised Fe3 O4 magnetic nanoparticles

The present study demonstrated the preparation of three different acid‐functionalised magnetic nanoparticles (MNPs) and evaluation for their catalytic efficacy in hydrolysis of cellobiose. Initially, iron oxide (Fe₃ O₄)MNPs were synthesised, which further modified by applying silica coating (Fe₃ O₄ ‐MNPs@Si) and functionalised with alkylsulfonic acid (Fe₃ O₄ ‐MNPs@Si@AS), butylcarboxylic acid (Fe₃ O₄ ‐MNPs@Si@BCOOH) and sulphonic acid (Fe₃ O₄ ‐MNPs@Si@SO₃ H) groups. The Fourier transform infrared analysis confirmed the presence of above‐mentioned acid functional groups on MNPs. Similarly, X‐ray diffraction pattern and energy dispersive X‐ray spectroscopy analysis confirmed the crystalline nature and elemental composition of MNPs, respectively. TEM micrographs showed the synthesis of spherical and polydispersed nanoparticles having diameter size in the range of 20–80 nm. Cellobiose hydrolysis was used as a model reaction to evaluate the catalytic efficacy of acid‐functionalised nanoparticles. A maximum 74.8% cellobiose conversion was reported in case of Fe₃ O₄ ‐MNPs@Si@SO₃ H in first cycle of hydrolysis. Moreover, thus used acid‐functionalised MNPs were magnetically separated and reused. In second cycle of hydrolysis, Fe₃ O₄ ‐MNPs@Si@SO₃ H showed 49.8% cellobiose conversion followed by Fe₃ O₄ ‐MNPs@Si@AS (45%) and Fe₃ O₄ ‐MNPs@Si@BCOOH (18.3%). However, similar pattern was reported in case of third cycle of hydrolysis. The proposed approach is considered as rapid and convenient. Moreover, reuse of acid‐functionalised MNPs makes the process economically viable.Inspec keywords: scanning electron microscopy, catalysis, magnetic separation, magnetic particles, silicon compounds, iron compounds, nanomagnetics, coatings, X‐ray chemical analysis, nanoparticles, X‐ray diffraction, nanofabrication, Fourier transform infrared spectra, organic compounds, nanocompositesOther keywords: catalytic efficacy, alkylsulfonic acid, butylcarboxylic acid, energy dispersive X‐ray spectroscopy analysis, spherical polydispersed nanoparticles, cellobiose hydrolysis, acid‐functionalised MNPs, acid functional groups, cellobiose conversion, acid‐functionalised magnetic nanoparticle, silica coating, sulphonic acid, Fourier transform infrared analysis, SEM micrograph, X‐ray diffraction pattern, size 20.0 nm to 80.0 nm, Fe₃ O₄ , Si, SiO₂      

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     

PANI/TiO2 nanocomposite‐based chemiresistive gas sensor for the detection of E. Coli bacteria

In the modern pace of the world, food safety is a major concern. In this work, a simple chemiresistive type gas sensor was fabricated to detect Escherichia Coli (E. coli) bacteria. Polyaniline (PANI) films were deposited on the indium tin oxide substrate by an electrochemical deposition method. TiO₂ nanoparticles were synthesised by facile hydrothermal method. PANI films were modified using hydrothermally prepared TiO₂ nanoparticles by a spin coating method. X‐ray diffraction (XRD), field emission scanning electron microscope (FESEM), Fourier transform infrared (FTIR) and ultraviolet– visible spectrophotometer techniques were used to characterise the PANI/TiO₂ nanocomposites. The peaks obtained in the XRD pattern confirmed the anatase phase of TiO₂ nanoparticles. FESEM analysis showed the nanofibrous structure of the nanocomposite. The FTIR characteristic peaks confirmed the formation of the nanocomposite. The electrical resistance of the sensors was evaluated as a function of the bacterial concentration. The PT2 (TiO₂ coated 5 times on PANI) in comparison with PT1 (TiO₂ coated 3 times on PANI) exhibited good sensitivity to the gas molecules at room temperature. The p‐n junction at PANI/TiO₂ interface improved the physical adsorption of gas molecules. Since no specific antibodies or receptors are used, the sensor has the potential for adaptation to real‐life applications. Thus low cost, real‐time, portable, reusable and sensitive bacteria sensors were fabricated and tested.Inspec keywords: conducting polymers, nanoparticles, nanocomposites, visible spectra, ultraviolet spectra, microorganisms, nanosensors, adsorption, gas sensors, nanofabrication, nanofibres, X‐ray diffraction, titanium compounds, spin coating, field emission scanning electron microscopy, Fourier transform infrared spectra, polymer films, electrodeposition, electrical resistivity, wide band gap semiconductors, biological techniques, nanobiotechnologyOther keywords: simple chemiresistive type gas sensor, polyaniline films, indium tin oxide substrate, electrochemical deposition method, TiO₂ nanoparticles, facile hydrothermal method, PANI films, spin coating method, gas molecules, portable bacteria sensors, reusable bacteria sensors, sensitive bacteria sensors, PANI‐TiO₂ nanocomposite‐based chemiresistive gas sensor, Escherichia Coli bacteria detection, X‐ray diffraction, XRD, field emission scanning electron microscopy, FESEM, Fourier transform infrared spectra, FTIR spectra, ultraviolet‐visible spectra, anatase phase, nanofibrous structure, electrical resistance, bacterial concentration, p‐n junction, physical adsorption, temperature 293.0 K to 298.0 K, TiO₂ , ITO     

Green synthesis of nanosilver‐decorated graphene oxide sheets

A green facile method has been successfully used for the synthesis of graphene oxide sheets decorated with silver nanoparticles (rGO/AgNPs), employing graphite oxide as a precursor of graphene oxide (GO), AgNO₃ as a precursor of Ag nanoparticles (AgNPs), and geranium (Pelargonium graveolens) extract as reducing agent. Synthesis was accomplished using the weight ratios 1:1 and 1:3 GO/Ag, respectively. The synthesised nanocomposites were characterised by scanning electron microscopy, transmission electron microscopy, atomic force microscopy, X‐ray diffraction, UV‐visible spectroscopy, Raman spectroscopy, energy dispersive X‐ray spectroscopy and thermogravimetric analysis. The results show a more uniform and homogeneous distribution of AgNPs on the surface of the GO sheets with the weight ratio 1:1 in comparison with the ratio 1:3. This eco‐friendly method provides a rGO/AgNPs nanocomposite with promising applications, such as surface enhanced Raman scattering, catalysis, biomedical material and antibacterial agent.Inspec keywords: silver, nanoparticles, graphene, nanocomposites, scanning electron microscopy, transmission electron microscopy, atomic force microscopy, X‐ray diffraction, ultraviolet spectra, visible spectra, X‐ray chemical analysis, surface enhanced Raman scattering, catalysis, nanofabricationOther keywords: antibacterial agent, biomedical material, catalysis, surface enhanced Raman scattering, rGO‐AgNP nanocomposite, eco‐friendly method, homogeneous distribution, thermogravimetric analysis, energy dispersive X‐ray spectroscopy, Raman spectroscopy, UV‐visible spectroscopy, X‐ray diffraction, atomic force microscopy, transmission electron microscopy, scanning electron microscopy, nanocomposites, reducing agent, geranium, graphene oxide sheets, graphite oxide, silver nanoparticles, green facile method     

Electrophoretic deposition of hydroxyapatite‐shrimp crusts nanocomposite thin films for bone implant studies

Hydroxyapatite‐shrimp crusts nanocomposite thin films were deposited on titanium substrates by electrophoretic technique, under different preparation conditions, for bone implant applications. Fourier transform infrared spectrometer, atomic force microscope, X‐ray diffraction (XRD), optical microscope, and scanning electron microscope were employed to characterise the synthesised films. Vickers’ micro‐hardness measurements revealed a value of 502 HV for the hydroxyapatite films and 314.55 HV for the nanocomposite films. XRD results confirmed the polycrystalline nature of the hydroxyapatite and hydroxyapatite‐shrimp nanocomposite films. The in‐vitro bioactivity test of the synthesised films in simulated body fluid showed very low dissolution rate. Antibacterial activity of synthesised films was investigated against E. coli bacteria.Inspec keywords: electrophoretic coating techniques, thin films, nanocomposites, antibacterial activity, bone, prosthetics, nanomedicine, calcium compounds, bioceramics, nanofabrication, Fourier transform infrared spectra, atomic force microscopy, X‐ray diffraction, optical microscopy, scanning electron microscopy, Vickers hardness, microhardness, microorganisms, dissolvingOther keywords: Ti, Ca₁₀ (PO₄)₆ (OH)₂ , E. coli bacteria, antibacterial activity, dissolution rate, simulated body fluid, in‐vitro bioactivity test, polycrystalline nature, Vickers microhardness measurements, XRD, scanning electron microscopy, optical microscopy, X‐ray diffraction, atomic force microscopy, Fourier transform infrared spectrometer, bone implant applications, titanium substrates, hydroxyapatite‐shrimp crust nanocomposite thin films, electrophoretic deposition     

Green chemistry synthesis of nano‐cuprous oxide

Green chemistry and a central composite design, to evaluate the effect of reducing agent, temperature and pH of the reaction, were employed to produce controlled cuprous oxide (Cu₂ O) nanoparticles. Response surface method of the ultraviolet–visible spectroscopy is allowed to determine the most relevant factors for the size distribution of the nanoCu₂ O. X‐ray diffraction reflections correspond to a cubic structure, with sizes from 31.9 to 104.3 nm. High‐resolution transmission electron microscopy reveals that the different shapes depend strongly on the conditions of the green synthesis.Inspec keywords: nanostructured materials, copper compounds, nanofabrication, pH, response surface methodology, ultraviolet spectra, X‐ray diffraction, transmission electron microscopyOther keywords: green chemistry synthesis, nanocuprous oxide, reducing agent, reaction pH, response surface method, ultraviolet‐visible spectroscopy, size distribution, cubic structure, high‐resolution transmission electron microscopy, X‐ray diffraction reflection, central composite design, Cu₂ O     

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     

Development and characterisation of novel Ce‐doped hydroxyapatite–Fe3 O4 nanocomposites and their in vitro biological evaluations for biomedical applications

Hydroxyapatite (HAP: Ca₁₀ (PO₄)₆ (OH)₂) is extensively used in biomedical field because of its biocompatibility, osteoconductivity and non‐toxicity properties. However, HAP exhibits poor mechanical strength and bacterial restriction behavior. To overcome these drawbacks, various metal ions such as Ag⁺, Zn²⁺, Cu²⁺, Ti⁴⁺ and Ce^4+/3+ are incorporated in HAP matrix to increase the mechanical and biological properties. Among these, Cerium (Ce) is selected as antibacterial agent due to its high thermal stability and its applications in dental fillings, bone healing and catheters. Fe₃ O₄ nanoparticles were used in hyperthermia treatment, magnetic fluid recordings and catalysis. In this present study, we have synthesized nanocomposites consisting of 1.25% Ce doped HAP with various concentrations of Fe₃ O₄ NPs as 90:10 (C‐1), 70:30 (C‐2) and 50:50 wt% (C‐3) using ball milling technique. The obtained Ce@HAP‐Fe₃ O₄ nanocomposites were characterized by ATR‐FTIR, XRD, VSM, SEM‐EDAX and TEM analysis. Further, the fabricated Ce@HAP‐Fe₃ O₄ nanocomposites were tested for its antibacterial activity towards Staphylococcus aureus (S. aureus) and Escherichia coli (E.coli), where C‐3 composites exhibit the excellent pathogen inhibition towards E.coli. In addition, the cytotoxicity evaluation on C‐3 nanocomposites by in vitro biocompatibility study using MG‐63 cells shows the prominent viable cell enhancement up to 400µg/mL concentrations.Inspec keywords: nanocomposites, iron compounds, calcium compounds, cerium, mechanical strength, antibacterial activity, biomedical materials, dentistry, bone, nanoparticles, nanofabrication, ball milling, Fourier transform infrared spectra, attenuated total reflection, X‐ray diffraction, magnetometry, scanning electron microscopy, transmission electron microscopy, microorganisms, cellular biophysics, nanomedicineOther keywords: Ce‐doped HAP–Fe3O4 nanocomposite, hydroxyapatite, in vitro biological evaluation, mechanical strength, bacterial restriction behaviour, metal ion, silver ion, zinc ion, copper ion, titanium ion, cerium ion, HAP matrix, antibacterial agent, thermal stability, dental filling, bone healing, catheter, Fe3O4 nanoparticle, hyperthermia treatment, magnetic fluid recording, catalysis, ball milling technique, Fourier transform infrared spectroscopy, attenuated total reflectance spectroscopy, X‐ray diffraction, vibrating sample magnetometry, scanning electron microscopy, SEM‐energy dispersive spectroscopy, transmission electron microscopy, TEM analysis, antibacterial activity, Staphylococcus aureus, Escherichia coli, pathogen inhibition, in vitro biocompatibility, MG‐63 osteoblast cell, cell enhancement, Ca₅ (PO₄)₃ (OH):Ce, Fe₃ O₄      

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     

Biosynthesis of Selenium Nanoparticles using yeast Nematospora coryli and examination of their anti‐candida and anti‐oxidant activities

Selenium (Se) is a rare and essential element for the human body and other living organisms because of its role in the structure of several proteins and having anti‐oxidant properties to reduce oxidative stress at cells. Some microorganisms can absorb Se oxyanions and convert them into zero‐valent Se (Se0) in the nanoscale dimensions, which can be used for producing Se nanoparticles (SeNPs). In the present study, SeNPs were intracellularly biosynthesised by yeast Nematospora coryli, which is an inexpensive method and does not involve using materials hazardous for human and environment. The produced NPs were refined by a two‐phase system and then characterised and identified by ultraviolet–visible, X‐ray diffraction, X‐ray fluorescence, transmission electron microscope, and Fourier transform infrared spectroscopy analyses. The structural analysis of biosynthesised SeNPs showed spherical‐shaped NPs with size ranging from 50 to 250 nm. Also, extracted NPs were applied to explore their anti‐candida and anti‐oxidant activities. The results of this investigation confirm the biological properties of Se.Inspec keywords: X‐ray diffraction, microorganisms, oxidation, transmission electron microscopy, reduction (chemical), nanomedicine, biomedical materials, visible spectra, nanoparticles, proteins, nanofabrication, selenium, ultraviolet spectra, particle size, Fourier transform infrared spectra, antibacterial activityOther keywords: proteins, oxidative stress, Se oxyanions, yeast, biosynthesised SeNPs, anti‐oxidant activities, human body, living organisms, Se nanoparticles, Nematospora coryli, anti‐candida activities, biosynthesis, ultraviolet–visible analysis, X‐ray diffraction, X‐ray fluorescence, transmission electron microscope, Fourier transform infrared spectroscopy, structural analysis, size 50.0 nm to 250.0 nm, Se     

Biosynthesis of γ ‐Fe2 O3 @CuO core–shell nanoclusters using aqueous extract of Sesbania grandiflora Linn fresh leaves,its characterisation,and antimicrobial activity studies against Staphylococcus aureus strains

The present study reports an eco‐friendly and rapid method for the synthesis of core–shell nanoclusters using the modified reverse micelle method. It is a green synthetic method which uses Sesbania grandiflora Linn extract which acts as a reducing and capping agent. It is observed that this method is very fast and convenient and the nanoclusters are formed with 5–10 min of the reaction time without using harsh conditions. The core–shell nanoclusters so prepared were characterised using UV–Vis spectroscopy, scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, and X‐ray photoelectron spectroscopy. Further, their effective antibacterial activity towards the gram‐positive bacteria Staphylococcus aureus was found to be due to their smaller particle size.Inspec keywords: iron compounds, copper compounds, nanoparticles, particle size, nanofabrication, nanomedicine, biomedical materials, core‐shell nanostructures, antibacterial activity, ultraviolet spectra, visible spectra, microorganisms, reduction (chemical), scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, X‐ray photoelectron spectraOther keywords: biosynthesis, γ‐Fe₂ O₃ ‐CuO core‐shell nanoclusters, aqueous extract, Sesbania grandiflora Linn fresh leaves, antimicrobial activity, Staphylococcus aureus strains, eco‐friendly method, modified reverse micelle method, green synthetic method, reducing agent, capping agent, UV‐visible spectroscopy, scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy, antibacterial activity, gram‐positive bacteria Staphylococcus aureus, particle size, time 5 min to 10 min, Fe₂ O₃ ‐CuO     

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     

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 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      

Magnetic core‐shell Fe3O4@TiO2 nanocomposites for broad spectrum antibacterial applications

The authors have synthesised a core‐shell Fe₃O₄@TiO₂ nanocomposite consisting of Fe₃O₄ as a magnetic core, and TiO₂ as its external shell. The TiO₂ shell is primarily intended for use as a biocompatible and antimicrobial carrier for drug delivery and possible other applications such as wastewater remediation purposes because of its known antibacterial and photocatalytic properties. The magnetic core enables quick and easy concentration and separation of nanoparticles. The magnetite nanoparticles were synthesized by a hydrothermal route using ferric chloride as a single‐source precursor. The magnetite nanoparticles were then coated with titanium dioxide using titanium butoxide as a precursor. The core‐shell Fe₃O₄@TiO₂ nanostructure particles were characterized by XRD, UV spectroscopy, and FT‐IR, TEM, and VSM techniques. The saturation magnetization of Fe₃O₄ nanoparticles was significantly reduced from 74.2 to 13.7 emu/g after the TiO₂ coating. The antibacterial studies of magnetic nanoparticles and the titania‐coated magnetic nanocomposite were carried out against gram+ve, and gram–ve bacteria (Staphylococcus aureus, Pseudomonas aeruginosa, Shigella flexneri , Escherichia coli, and Salmonella typhi) using well diffusion technique. The inhibition zone for E. coli (17 mm after 24 h) was higher than the other bacterial strains; nevertheless, both the uncoated and TiO₂‐coated magnetite nanocomposites showed admirable antibacterial activity against each of the above bacterial strains.