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In this study, by using a co-precipitation method MoO3/CuO/ZnO nanocomposite material was synthesized. Then the prepared material was fully characterized by using XRD (X-ray diffraction), SEM (scanning electron microscopy), EDS (energy dispersive x-ray spectroscopy), CV (cyclic voltammetry), and EIS (Electrochemical Impedance Spectroscopy). Zeta potential and hydrodynamic size were measured using a Zetasizer in PBS buffer. By using Scherrer’s formula from XRD, particle size was determined which was around 26.5 nm. For the promising chemical sensor development, MoO3/CuO/ZnO nanocomposite material was fabricated onto a glassy carbon electrode (GCE) to provide a sensor probe with a fast response towards the selective hydrazine (HZ) toxin in phosphate buffer phase. The fabricated sensor probe is exhibited good sensitivity and long-term stability as well as enhanced electrochemical performances. A calibration plot was found linear in the range of 0.2 nM to 2.0 mM (linear dynamic range, LDR) in presence of aqueous HZ solutions with highest sensitivity value and lower limit of detection and good limit of quantification (LOQ). This approach is promising as an efficient technique in developing a highly effective sensor probe with ternary metal oxides for detecting environmental pollutants on a broad scale. [ABSTRACT FROM AUTHOR]

The synthesized MgTi2O4⋅TiO2⋅Zn2TiO4 nanomaterial was characterized by XRD (X‐Ray diffraction), SEM (Scanning electron microscopy), EDS (Energy dispersive x‐ray spectroscopy), FTIR (Fourier transform infrared spectroscopy) and PL (Photoluminescence) study. Particles size of MgTi2O4⋅TiO2⋅Zn2TiO4 nanomaterial was found to be 37.3 nm. PL and PLE (Photoluminescence excitation) spectra are showed several peaks including one red PL at 723 nm, when excited at 320 nm. Nanomaterial was subject to electrochemical sensor study. Thin layer of synthesized MgTi2O4⋅TiO2⋅Zn2TiO4 nanomaterials was fabricated onto the glassy carbon electrode (GCE) with conducting binder to result the working electrode of 4‐nitrophenylhydrazine (4‐NPHyd) sensor, which was applied successively to selectively detect the 4‐NPHyd in aqueous phase. The 4‐NPHyd chemical sensor exhibited high sensitivity with lower detection limit, long‐term stability in chemical environment and improved electrochemical responses during sensing performance. The linearity of calibration plot is obtained over the large linear dynamic range (LDR) from 0.1 nM to 0.1 mM of 4‐NPHyd. The sensitivity calculated from the slop of calibration plot (ratio of current to concentration of 4‐NPHyd) is 42.7215 μAmM−1cm−2 with detection limit (DL) of 0.02±0.001 nM at signal to noise ratio of 3(S/N). Therefore, the chemical sensor based on MgTi2O4⋅TiO2⋅Zn2TiO4 nanomaterials may be a promising highly sensitive sensor in electrochemical method for the effective detection of hazardous and carcinogenic chemicals in medical as well as biological sectors. [ABSTRACT FROM AUTHOR]

In this approach, Ag·SrSnO3 nanocomposites were synthesized by a co-precipitation method and characterized by IR, XRD, SEM, EDS, CV, EIS, and TEM measurements. The nanocomposite Ag·SrSnO3 was crystallized in nanorods (NRs) with Ag on the surface, as revealed by SEM and TEM studies. Ag·SrSnO3 shows excellent photocatalysis for dye degradation and anti-bacterial activity against both Gram positive and Gram negative pathogenic bacteria. Here, to develop a selective 2,4-diaminophenylhydrazine (2,4-DAPHyd) electrochemical sensor, a thin layer of prepared Ag·SrSnO3 NRs was deposited onto a glassy carbon electrode (GCE) with Nafion as the conductive binder (5% Nafion) in ethanol. The slope obtained from the curve of a plot of current versus concentration of 2,4-DAPHyd, denoted the calibration curve, was used to calculate the sensitivity (7.5854 μA μM−1 cm−2) of the Ag·SrSnO3 NRs sensor. The linear dynamic range (LDR) of detection is 0.1 nM–0.01 mM. The lowest limit of detection (LOD; 96.13 ± 4.81 pM) of the Ag·SrSnO3 NR sensor was calculated at S/N = 3 (signal to noise ratio). Furthermore, the Ag·SrSnO3 NR sensor shows good reproducibility, long duration for performing sensing ability and a short response time and validation in real samples, which were collected and extracted from various sources. [ABSTRACT FROM AUTHOR]

Schematic representation showing (a) Ag 2 O·SnO 2 ·TiO 2 nanomaterials coated GCE with conducting nafion (5 % ethanol) coating binders, (b) expected I–V response by the Ag 2 O·SnO 2 ·TiO 2 nanomaterials/GCE, (c) observed electrochemical response by the Ag 2 O·SnO 2 ·TiO 2 nanomaterials/GCE, and (d) proposed detection mechanism of TU, while TU is reduced by removing conducting electrons from the Ag 2 O·SnO 2 ·TiO 2 nanomaterials/GCE electrodes. • Synthesized multifunctional nanomaterial with high dye degradation efficiency. • Ag 2 O·SnO 2 ·TiO 2 /Nafion/GCE sensor assembly determine Thiourea from 0.10 nM to 0.10 M. • Sensitivity and LOD were obtained as 4.2913 μAμM−1 cm−2 and 2.3 ± 0.1 pM (S/N = 3). • Anti-bacterial activity against Gram positive and Gram negative bacteria observed. A novel multifunctional material with high dye degradation efficiency, photoluminescence (PL) and electro-sensing ability was synthesized with a simple co-precipitation method followed by thermal calcination. The dye degradation efficiency was 98% at pH 9 within only 60 min. The material also showed excellent anti-bacterial activity against both Gram positive and Gram negative bacteria in the presence and absence of light. For the electro-sensor application of Ag 2 O·SnO 2 ·TiO 2 , glassy carbon electrode (GCE) was modified by the Ag 2 O·SnO 2 ·TiO 2 nanomaterials at room conditions. The resulting Ag 2 O·SnO 2 ·TiO 2 /Nafion/GCE sensor assembly was employed to determine Thiourea (TU) by a simple and reliable electrochemical approach at low-potential. Hazardous TU was selected as the target analyte by the selectivity study. In the investigative study, for the TU concentrations of 0.10 nM to 0.10 M, the calibration plot was found linear (r2 = 0.9997). Calculated sensitivity and limit of detection values were obtained as 4.2913 μAμM−1 cm−2 and 2.3 ± 0.1 pM (S/N = 3) respectively. [ABSTRACT FROM AUTHOR]