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The electroanalytical properties of Sn-decorated α-Fe2O3 nanoparticles have been synthesized by a facile co-precipitation method and the obtained nanoparticles were successfully used for determination of hydrazine. The structural and morphological of the as-prepared nanoparticles were employed using X-ray diffraction (XRD), Fourier-transform infrared (FTIR), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HR-TEM) techniques. It was revealed from HR-TEM micrographs that tiny Sn nanoparticles grew well on the surface of α-Fe2O3 nanostructure. Optical property of the sample was characterized using UV–Vis spectroscopy. Electrocatalytic activities of Sn/α-Fe2O3 modified electrode was studied using cyclic voltammetry and amperometric measurements in 0.1 M PBS electrolyte towards N2H4 electro-oxidation. The limit of detection for the determination of N2H4 was found to be 10 nM. The modified electrode possessed sensitivities of 41.04 µA cm−2 mM−1 and 13.05 µA cm−2 mM−1 and wide linear ranges from 0.01 × 10−6 to 2.5 × 10−3 M with co-relation coefficient of R2 = 0.998 and R2 = 0.997, respectively. The Sn/α-Fe2O3 modified electrode also proves good reproducibility, long-term stability, selectivity and good antifouling properties. The Sn/α-Fe2O3 modified electrode sensor successfully demonstrated the practical applicability for detection of N2H4 in the real sample analysis. [ABSTRACT FROM AUTHOR]

A novel rhodamine-tryptamine conjugate-based fluorescent and chromogenic chemosensor (RTS) for detection of Hg2+ present in water was reported. After gradual addition of Hg2+ in aqueous methanol solution of RTS, a strong orange fluorescence and deep-pink coloration were observed. The probe showed high selectivity towards Hg2+ compared to other competitive metal ions. The 1:1 binding stoichiometry between RTS and Hg2+ was established by Job's plot analysis and mass spectroscopy. Initial studies showed that the synthesized probe RTS possessed fair non-toxicity and effectively passed through cell walls of model cell systems, viz., human neuroblastoma (SHSY5Y) cells and cervical cells (HeLa) to detect intercellular Hg2+ ions, signifying its utility in biological system. The limit of detection (LOD) was found to be 2.1 nM or 0.42 ppb by fluorescence titration. Additionally, the potential relevance of synthesized chemosensor for detecting Hg2+ ions in environmental water samples has been demonstrated.ᅟ [ABSTRACT FROM AUTHOR]

Single-phase cobalt ferrite (CoFe2O4) nanopowder, with average particle size ∼20 nm, has been synthesised using an ethylene diamine tetra acetic acid precursor-based method. CoFe2O4nanopowder was obtained by calcining precursor at 550°C for 4 h in air. The change of microstructure of the synthesised CoFe2O4with increasing sintering temperature was studied using scanning electron microscopy. DC electrical resistivities of unsintered and sintered samples were measured using a two-probe method. Room temperature magnetic hysteresis measurement revealed that the synthesised CoFe2O4nanopowder exhibited ferromagnetic behaviour at room temperature with saturation magnetisation of 67.55 emu/g and coercivity of 1645.24 Oe. [ABSTRACT FROM PUBLISHER]

A novel 'one-pot' synthetic method has been reported for the preparation of (NiFe2O4)x-(BaFe12O19)1−x composites. The synthesized composites were characterized using thermogravimetric analysis, differential scanning calorimetric analysis, X-ray diffraction, dynamic light scattering technique, scanning electron microscopy, and vibrating sample magnetometer. The (NiFe2O4)x-(BaFe12O19)1−x composites prepared by this method showed crystallographically two phase behavior, but magnetically a good single phase exchange spring-coupled behavior with high saturation magnetization as well as high coercivity. [ABSTRACT FROM AUTHOR]