No abstract

No abstract

This paper describes green, simple, and efficient method for the synthesis of magnetite nanoparticles (Fe3O4 NPs) using Acacia concinna fruit extract for the first time. A. concinna fruit extract is used as reducing and stabilizing agent. Reduction of Fe3+ ions by A. concinna fruit extract is examined by UV‐visible absorption spectra (UV‐Vis‐NIR). To recognize the functional group responsible for Fe3O4, the NPs are characterized by Fourier transform infra‐red spectroscopy (FTIR). The structural analysis of Fe3O4 NPs is done by X‐ray diffraction (XRD) which confirms cubic spinel structure and the average crystallite size of obtained NPs is found to be 28 nm. The morphological studies of Fe3O4 NPs are done by scanning electron microscope (SEM) which depicts the quasi‐spherical morphology. The green synthesized Fe3O4 NPs shows distinctive antibacterial activities against gram‐negative E. coli and Pseudomonas aeruginosa microorganism which confirms its potential in biomedical applications.

The complex decomposition approach was used for the synthesis of MFe 2 O 4 magnetic nanoparticles (MNPs) by substituting M as Co, Mn, and Zn. The obtained MNPs were characterized for magneto-structural properties using X-Ray diffraction patterns, FTIR, Raman and Mossbauer spectroscopy techniques which validate the synthesis of phase pure cubic spinel ferrite (space group Fd3m) with five Raman active modes. Magnetic properties confirmed using Mossbauer spectroscopy. The size, morphology, and compositional analysis was performed using HRTEM and EDX where the size of MNPs was found to be less than 10 nm that attains superparamagnetism with 39.0, 58.28, and 44.24 emu gm −1 moment for CoFe 2 O 4 , MnFe 2 O 4 , and ZnFe 2 O 4 , respectively. The magnetic hyperthermia performance of obtained MNPs was evaluated by induction heating experiments at magnetic field range 13.3-26.7 kAm −1. The specific absorption rate (SAR) and intrinsic loss power (ILP) values were determined at different magnetic fields and mutually related with magneto-structural properties to evaluate its potential for magnetic particle hyperthermia therapy. The CoFe 2 O 4 MNP exhibits a maximum temperature rise of 25 and 35 °C for 5 and 10 mgmL −1 concentrations with threshold temperature rise.

Introduction: Herein we report the green synthesis and characterization of silverreduced graphene oxide nanocomposites (Ag-rGO) using Acacia nilotica gum for the first time. Experimental: We demonstrate the Hg2+ ions sensing ability of the Ag-rGO nanocomposites form aqueous medium. The developed colorimetric sensor method is simple, fast and selective for the detection of Hg2+ ions in aqueous media in presence of other associated ions. A significant color change was noticed with naked eye upon Hg2+ addition. The color change was not observed for cations including Sr2+, Ni2+, Cd2+, Pb2+, Mg2+, Ca2+, Fe2+, Ba2+ and Mn2+indicating that only Hg2+ shows a strong interaction with Ag-rGO nanocomposites. Under the most suitable condition, the calibration plot (A0-A) against concentration of Hg2+ was linear in the range of 0.1-1.0 ppm with a correlation coefficient (R2) value 0.9998. Results & Conclusion The concentration of Hg2+ was quantitatively determined with the Limit of Detection (LOD) of 0.85 ppm. Also, this method shows excellent selectivity towards Hg2+ over nine other cations tested. Moreover, the method offers a new cost effective, rapid and simple approach for the detection of Hg2+ in water samples.