Biological synthesis, physico-chemical characterization of undoped and Co doped α-Fe2O3 nanoparticles using Tribulus terrestris leaf extract and its antidiabetic, antimicrobial applications

2021 ◽  
Vol 12 (4) ◽  
pp. 045003
Author(s):  
A S Sakthi Athithan ◽  
J Jeyasundari ◽  
Y B A Jacob

Abstract Hematite (α-Fe2O3) nanoparticles (NPs) were chemically and thermodynamically more stable among iron oxide nanoparticles. Doping of Co2+ metal ion in α-Fe2O3 can modify the structural, optical and magnetic properties of NPs and also enhances the potential of the biomedical applications. In the current study, undoped and Co doped hematite nanoparticles were synthesised by co-precipitation method using Tribulus terrestris L. leaf extract as bio-reductant. The magnetic, optical and structural investigations were studied with the help of Ultraviolet-visible (UV-Vis), Fourier Transform Infrared (FTIR), Scanning Electron Microscopy equipped with Energy Dispersive X-ray (SEM-EDX) Spectroscopy, Vibrating Sample Magnetometer (VSM) and X-ray Diffraction (XRD) Spectroscopy. XRD analysis shows that synthesized nanoparticles were in hematite phase, rhombohedral in structure. XRD spectral pattern clearly evidenced that prepared α-Fe2O3 and Co-Fe2O3 NPs were highly crystalline with no impurity peaks. Using VSM spectra, the M-H curve indicates that saturation magnetisation (Ms) value increases for Co-Fe2O3 NPs than undoped α-Fe2O3 NPs, it can be clearly seen that doping largely affects the magnetic nature of nanoparticles. In the UV-Vis spectra, absorption maxima increases and band gap value decreases for cobalt doped hematite nanoparticles indicating the substitution of Fe2+ ions by Co2+ ions in α-Fe2O3 lattice sites. Antidiabetic and antimicrobial activity of the synthesized undoped and Co doped hematite NPs were tested by alpha-amylase inhibitory and disc diffusion method. The Co-Fe2O3 NPs have greatly inhibited the digestive enzyme and microbial strains as compared to undoped α-Fe2O3 NPs.

2020 ◽  
Vol 3 (2) ◽  
Author(s):  
Aarth R ◽  
Sudha A P ◽  
Sujatha B ◽  
Sowmya Lakshmi K

The phytosynthesis of n-type Cadmium Oxide Nanoparticles reduces the toxicity of the substance and makes it Eco-friendly. This Eco-friendly biosynthesis of CdO NPs was synthesized for the first time from the Queen of herbs, Ocimum Sanctum (holy basil).The biosynthesized Cadmium oxide was prepared using Ocimum leaf extract as a reductant and Cadmium Chloride and hydroxide as cadmium and oxide source materials by Co- Precipitation method. Thus obtained Cadmium Oxide Nanoparticles were characterized by different techniques such as X-ray diffraction (XRD), Fourier Transform infrared spectroscopy (FTIR), Scanning electron microscope (SEM),Energy dispersive X-ray spectroscopy(EDS) to study the structural and morphological properties. XRD pattern exhibited the formation of face centered cubic structure of CdO NPs with an average crystalline size of 11.5nm .The chemical bond formation of CdO NPs were confirmed by FTIR spectrum in the range of (400-4000cm-1). The SEM micrographs revealed the predominant formation of Cauliflower shape with a particle size in the range of 61-142nm. The high purity of the biosynthesized nanoparticles were confirmed by EDS analysis. Further it was tested against gram positive and gram negative bacterial strains and showed significant antibacterial activity. This biosynthetic research study opens an innovative window to progress our understanding of how CdO NPs shows resistance to different bacterial strains.


Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1505
Author(s):  
Simona Liliana Iconaru ◽  
Carmen Steluta Ciobanu ◽  
Daniela Predoi ◽  
Mikael Motelica-Heino ◽  
Constantin Cătălin Negrilă ◽  
...  

Hydroxyapatite (Ca10(PO4)6(OH)2, HAp), due to its high biocompatibility, is widely used as biomaterial. Doping with various ions of hydroxyapatite is performed to acquire properties as close as possible to the biological apatite present in bones and teeth. In this research the results of a study performed on thin films of hydroxyapatite co-doped with nitrogen and bromine (NBrHAp) are presented for the first time. The NBrHAp suspension was obtained by performing the adapted co-precipitation method using cetyltrimethylammonium bromide (CTAB). The thin layers of NBrHAp were obtained by spin-coating. The stability of the NBrHAp suspension was examined by ultrasound measurements. The thin layers obtained by the spin-coating method were examined by scanning electron microscopy (SEM), optical microscopy (OM), and metallographic microscopy (MM). The presence of nitrogen and bromine were highlighted by energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) studies. Fourier transform infrared spectroscopy (FTIR) was used to highlight the chemical status of nitrogen and bromine. In addition, the powder obtained from the NBrHAp suspension was analyzed by XRD. Moreover, the in vitro antimicrobial activity of the NBrHAp suspensions and coatings was investigated using the reference microbial strains Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Candida albicans ATCC 10231. The results highlighted the successful obtainment of N and Br co-doped hydroxyapatite suspension for the first time by an adapted co-precipitation method. The obtained suspension was used to produce pure NBrHAp composite thin films with superior morphological properties. The NBrHAp suspensions and coatings exhibited in vitro antimicrobial activity against bacterial and fungal strains and revealed their good antimicrobial activity.


2011 ◽  
Vol 63 (5) ◽  
pp. 917-923 ◽  
Author(s):  
Jun Hu ◽  
Donglin Zhao ◽  
Xiangke Wang

Multiwalled carbon nanotubes (MWCNTs)/iron oxide magnetic composites (named as MCs) were prepared by co-precipitation method, and were characterised by scanning electron microscope (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) in detail. The prepared MCs were employed as an adsorbent for the removal of Pb(II) and Cu(II) ions from wastewater in heavy metal ion pollution cleanup. The results demonstrated that the sorption of Pb(II) and Cu(II) ions was strongly dependent on pH and temperature. The experimental data were well described by Langmuir model, and the monolayer sorption capacity of MCs was found to vary from 10.02 to 31.25 mg/g for Pb(II) and from 3.11 to 8.92 mg/g for Cu(II) at temperature increasing from 293.15 to 353.15 K at pH 5.50. The sorption capacity of Pb(II) on MCs was higher than that of Cu(II), which was attributed to their ionic radius, hydration energies and hydrolysis of their hydroxides. The thermodynamic parameters (i.e., ΔH0, ΔS0 and ΔG0) were calculated from temperature dependent sorption isotherms, and the results indicated that the sorption of Pb(II) and Cu(II) ions on MCs were spontaneous and endothermic processes.


2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Dhivya B ◽  
Sujatha K ◽  
Sudha A P

The conventional methods for the synthesis of metal oxides intake large amount of hazardous chemicals, the best promising alternative is the use of plant extracts. In this work, calcium oxide nanoparticles of 16 nm size with the cubic shape were synthesized using the papaya leaf extract by the simple greener route using calcium chloride as a source material by co-precipitation method. By using the XRD (X-Ray Diffraction), FTIR (Fourier Transform Infrared Spectroscopy), SEM (Scanning Electron Microscope) and EDAX (Energy Dispersive X-ray Analysis), the structural,surface morphology, functional group and the antibacterial activity of the synthesized calcium oxide nanoparticles were analyzed. The XRD pattern of the CaO nanoparticles was well matched with the standard value and the crystalline size obtained using the Scherer formula was 16 nm. The elemental composition of the prepared sample was confirmed by the EDAX result. The presence of the functional groups of the synthesized CaO nanoparticles was confirmed by the FTIR analysis (4000-400 cmˉ1). The cubic morphology was identified from the SEM image and the grain size ranges from 125-218 nm. The CaO nanoparticles were further evaluated for their antibacterial activity against Staphylococcus aureus and klebsiella pneumonia and from the result it was found that CaO nanoparticles was active against both gram positive and gram negativebacteria.Therefore, it may be an emerging platform for new medicines.


2021 ◽  
Vol 19 ◽  
Author(s):  
Moinuzzaman ◽  
Mohammad Abu Hena Mostofa Jamal ◽  
Helal Uddin ◽  
Shahedur Rahman ◽  
Abdul Momin ◽  
...  

Background: In new modern science Nanotechnology is an emerging field for the researchers. Nanotechnology deals with the Nanoparticles. These Nanoparticles have a size of 1-100 nm in one dimension which are important part of biomedical science and medical chemistry, atomic physics, and all other known fields. Nanoparticles are used in broad range due to its small size, orientation, physical properties. Objectives: This study was designed to synthesized Silver nanoparticles using Azadirachta indica (Neem) leaf extract and evaluate biomedical application. Methods: Aqueous extract of Azadirachta indica is used for the synthesis of AgNPs. 1ml of the extract was added to (30- 60) ml of 1mM solution of silver nitrate drop by drop. Silver nanoparticle was characterized by UV-Visible Spectroscopy, Fourier Transform Infrared Spectroscopy, Dynamic Light Scattering Spectroscopy, X-ray Diffraction, Transmission Electron Microscopy, Antibacterial activity studies. Results: The Biological synthesis of Silver nanoparticles (AgNPs) was done by using the aqueous solution of Azadirachta indica leaf extract and AgNO3. A fixed ratio of plant extract to metal ion was used to prepare AgNPs and the formation of the nanoparticles was observed by the color change. The nanoparticles were characterized by UV-vis Spectrophotometer, FTIR, DLS, XRD and TEM. The nanoparticles were found have the size ranges from 30-60 nm. The biosynthesized silver nanoparticles had bactericidal effect against antibiotic resistance pathogenic microorganisms such as Bascillus subtilis, pseudomonas aeruginosa and Bascillus cereus. Conclusion: Silver nanoparticles were synthesized by Azadirachta indica leaf extract can be used as a therapeutic candidate for biomedical applications.


2021 ◽  
Author(s):  
Alaa Abdallah ◽  
Ramadan Awad

Abstract Pure and different concentrations from (Gd, Ru) co-doped NiO nanoparticles, capped with Polyvinylpyrrolidone (PVP), were fabricated by the co-precipitation method. The nanoparticles were characterized by different techniques. The Rietveld refinements of X-Ray Diffraction (XRD) patterns confirmed the formation of the pure face-centered-cubic NiO phase. The X-ray Photo-induced Spectroscopy (XPS) assured the trivalent oxidation state of the doped ions Gd3+ and Ru3+ and unveiled the multiple oxidation states of nickel ions (Ni2+ and Ni3+), emerging from the vacancies in the samples. The Transmission Electron Microscope (TEM) images showed the pseudospherical morphology of the samples and the Energy Dispersive X-ray permitted the quantitative analysis of the presented elements and their homogeneous distribution. The Raman and Fourier Transform Infra-Red (FTIR) spectra depicted the fundamental vibrational bands of NiO nanoparticles, confirming their purity. The UV-visible spectroscopy enabled the absorption measurements and the energy gap calculations. The co-dopants increased the energy bandgap of NiO nanoparticles from 3.15 eV for pure NiO to 3.62 eV with the highest concentration of the co-dopants (x = 0.02) The photoluminescence (PL) spectra gave insights into the possible defects present in the samples, such as nickel vacancies, single and double oxygen vacancies, and oxygen interstitials. The Vibrating Sample Magnetometer (VSM) studied the room temperature M-H loops of the co-doped samples. A combination of ferromagnetic, antiferromagnetic, and paramagnetic contributions was noticed and treated according to the law of approach to saturation and bound magnetic polaron (BMP) model. The magnetic parameters, such as the saturation magnetization, exchange and anisotropy field, and the BMP concentration were extracted from the fitted models and discussed in terms of the co-dopants’ concentration. The co-doped samples showed a softer magnetic behavior, which is recommended for data storage applications.


Author(s):  
Arun Babu Birusanti ◽  
Umamahesh Mallavarapu ◽  
Devanna Nayakanti ◽  
Chandra Sekhar Espenti

Objective: The motto of this research work was to synthesize the zinc oxide nanoparticles (ZnONPs) should be environmental friendly. Hence, it receives more attention toward the green route method.Methods: At last, the Ficus racemosa ZnONPs (FR-ZnONPs) were successfully synthesized using a simple protocol and eco favorable technique. This paper highlights the biosynthesis of ZnONPs using leaf extract of F. racemosa. Results: FR-ZnONPs formation was confirmed by the different spectral analysis such as UV-visible spectroscopy, Fourier transform-infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), and electronic dispersive X-ray spectroscopy. UV-visible studies revealed that the intrinsic band gap absorptions were at 372 nm and photoluminescence study showed that the blue emission at 492, 481, 473, and 450 nm and the green emission at 540 nm, respectively. FR-ZnONPs are wurtzite hexagonal structure with an average grain size of 15 nm was found from XRD analysis.Conclusion: FR-ZnONPs exhibited good antimicrobial efficacy on Escherichia coli and Staphylococcus aureus with various concentrations (100 μg/mL, 75 μg/mL, and 50 μg/mL) by disc diffusion method. The results showed the good antibacterial activity of FR-ZnONPs on G+ve and G-ve bacteria.


2007 ◽  
Vol 280-283 ◽  
pp. 521-524
Author(s):  
Li Qiong An ◽  
Jian Zhang ◽  
Min Liu ◽  
Sheng Wu Wang

Yb3+ and Ho3+ co-doped Lu2O3 nanocrystalline powders were synthesized by a reversestrike co-precipitation method. The as-prepared powders were examined by the X-ray diffraction and transmission electron microscopy. The phase composition of the powders was cubic and the particle size was in the range of 30~50 nm. Emission and excitation spectra of the powders were measured by a spectrofluorometer and the possible upconversion luminescence mechanism was also discussed.


2016 ◽  
Vol 16 (4) ◽  
pp. 3534-3541
Author(s):  
Yanqiu Zhang ◽  
Baojiu Chen ◽  
Xiangping Li ◽  
Jiashi Sun ◽  
Jinsu Zhang ◽  
...  

Nanosized Gd6WO12 phosphors containing various Er3+ concentrations and fixed Yb3+ concentration were synthesized by a co-precipitation method. The crystal structure and microscopic morphology of the obtained nanophosphors were characterized by means of X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). Two-photon processes for both the green and red upconversion (UC) emissions were confirmed by analyzing the dependence of UC intensities on 980 nm laser working current. UC emission intensity changing with temperature displays different trends for the samples with different Er3+ concentrations. The experimental results indicated that thermal quenching behavior of UC luminescence could not be simply explained by crossover mechanism. The enhancement for green UC emission in the sample with higher Er3+ concentration was discussed. Finally, the Er3+ concentration dependence of UC luminescence was experimentally observed, and its mechanisms were analyzed.


2012 ◽  
Vol 584 ◽  
pp. 248-252
Author(s):  
B. Sankara Reddy ◽  
S. Venkatramana Reddy ◽  
R.P. Vijaya Lakshmi ◽  
N. Koteeswara Reddy

Pure ZnO and Ag, Co doped ZnO nano particles [Zn1-xAgxCoyO, where x = 0.00 and 0.05, y = 0.05] were synthesized by chemical co precipitation method without use of surfactant. All the prepared samples calcinated in 1 hour at 500oC, after that the morphology of the samples were evaluated by Scanning Electron Microscope (SEM). The X- ray diffraction (XRD) results indicated that the synthesized co-doped ZnO nano crystals had the pure hexagonal structure without any significant change in the structure affected by Ag and Co substitution. Dopant elements Ag and Co are present in the ZnO host material and conformed by Energy Dispersive Analysis of X-ray Spectra (EDAX). The incorporation of Ag+ in the place of Zn2+ has made a considerable decrease in the size of nano crystals as compared to pure ZnO nano particles (It is to be noted that Co should be kept constant at 5 mol %). Blue emission was observed by Photo Luminescence (PL) Spectra.


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