Publications

A series of thiophene-3-carbonitrile contaning schiff bases were synthesized, characterized by the reaction of 2-amino-4,5,6,7-tetrahydro-benzo[b] thiophene-3-carbonitrile and corresponding active aldehyde under microwave irradiation and screened for their antibacterial activities. The structure of synthesized compounds were established by spectroscopic (FT-IR, H-1 NMR, C-13 NMR, Mass) and elemental analyses. The antibacterial activity of these compounds were first tested in vitro by the disk diffusion assay against two Gram-positive and two Gram-negative bacteria and then the minimum inhibitory concentration was determined with the reference of standard drug chloramphenicol. The results showed that compound 6 is better at inhibiting the growth as compared to chloramphenicol against both types of the bacteria (gram-positive and gram-negative).

In search for new potential inhibitors some new fluorine substituted thiobarbituric acid derivatives (2-4, 7, 8) and their fused/isolated heterobicyclic nitrogen systems (5, 6, 9, 10, 11, 12) have been synthesized from heterocyclization of fluorinated 1,3-diketoamine (1) with CS2 followed by ring closure reactions with primary nitrogen reagents. Structures of the targets have been established from elemental analysis and spectral data. Some synthesized systems have been evaluated as anti-HIV-1 and of cyclin-dependent kinase 2 (CDK2) for cell tumor division.

Herein, novel Co₃O₄·CdO·ZnO-based tri-metallic oxide nanoparticles (CCZ) were synthesized by a simple solution method in basic phase. We have used Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Field Emission Scanning Electron Microscope (FESEM), Dynamic Light Scattering (DLS), Tunneling Electron Microscopy (TEM), and Energy-Dispersive Spectroscopy (EDS) techniques to characterize the CCZ nanoparticles. XRD, TEM, DLS, and FESEM investigations have confirmed the tri-metallic nanoparticles' structure, while XPS and EDS analyses have shown the elemental compositions of the CCZ nanoparticles. Later, a Au/μ-Chip was modified with the CCZ nanoparticles using a conducting binder, PEDOT: PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate) in a sol-gel system, and dried completely in air. Then, the CCZ/Au/μ-Chip sensor was used to detect methanol (MeOH) in phosphate buffer solution (PBS). Outstanding sensing performance was achieved for the CCZ/Au/μ-Chip sensor, such as excellent sensitivity (1.3842 µAµM^-1cm^-2), a wide linear dynamic range of 1.0 nM-2.0 mM (R² = 0.9992), an ultra-low detection limit (32.8 ± 0.1 pM at S/N = 3), a fast response time (~11 s), and excellent reproducibility and repeatability. This CCZ/Au/μ-Chip sensor was further applied with appropriate quantification results in real environmental sample analyses.

Herein, a newly developed non-noble metal water splitting catalyst based on NiCuCoS3 was reported. Water splitting catalysts are largely developed with noble-based transition metals to lower the energy requirement for the overall water splitting reactions. However, the high cost of precious metal-based catalyst necessitated ongoing search for cheap and efficient oxygen and hydrogen evolution reaction catalysts. NiCuCoS3 were prepared by solventless solid state method and was well characterized by several techniques including field emission scanning electron microscopy (FESEM), X-ray diffraction spectroscopy (XRD), X-ray photoelectron spectroscopy (XPS), Fourier Transform infrared red spectroscopy (FTIR), energy dispersive X-ray spectroscopy (XEDS). The as-prepared NiCuCoS3 was applied for water splitting activities with satisfactory performance. The onset for the oxygen evolution reaction (OER) in 1 M KOH was noticed at the electrode potential E = 1.78 V/RHE (vs. the reversible hydrogen electrode corresponding to an overpotential η = 0.55 V, with a current density of 10 mA cm−2 obtained at E = 1.92 V/RHE (η = 0.69 V). Similarly, the hydrogen evolution reaction (HER) occurred at an onset of E = −0.58 V/RHE, with a current density of 10 mA/cm2 obtained at E = 0.60 V/RHE (with η equal to E vs. RHE for the HER). Likewise, OER and HER had Tafel slopes (130 mV/dec and −116 mV/dec respectively). The developed catalyst also showed high stability as established by linear sweep voltammetry, chronoamperometry and chronopotentiometry. This approach is seen as the right track of making water electrolysis for hydrogen energy feasible through provision of low-energy requirement for electrolytic process.