http://nopr.niscpr.res.in/handle/123456789/54003 2026-10-10T21:42:58Z http://nopr.niscpr.res.in/handle/123456789/54010 Title: Synthesis, physico-chemical characterization and antibacterial studies of new Fe(III) and Cr(III) complexes with an ionic liquid-supported Schiff base ligand Authors: Saha, Sanjoy; Barman, Indrajit; Sinha, Biswajit Abstract: An ionic liquid-supported Schiff base 1-{2-(2-hydroxy-5-bromobenzylamine)ethyl}-3-ethylimidazolium tetrafluoroborate and its Fe(III) and Cr(III) complexes has been prepared and characterized by various analytical and spectroscopic methods such as elemental analysis, UV-visible, FTIR,¹H NMR, mass spectra, TGA/DTG, molar conductance and magnetic susceptibility measurements. Based on these spectral studies octahedral geometry has been proposed for both complexes. Molar conductance of the complexes is showing their electrolytic nature. The Schiff base ligand and its complexes have tested for <em>in</em> <em>vitro</em> antibacterial activities against gram positive and gram negative bacteria to assess their inhibition potentials. Cr(III) complex has shown higher activity than the Fe(III) complex against the tested bacteria <em>S. aureus</em> and <em>E. coli.</em> Page(s): 155-161 2020-02-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/54009 Title: Potentiometric sensors selective for Cu(II) determination in real water samples and biological fluids based on graphene and multi-walled carbon nanotubes modified graphite electrodes Authors: Frag, Eman Y Z; Mohamed, Marwa E; Ali, Aya E; Mohamed, Gehad G Abstract: Three newly synthesized Cu(II) ion selective electrodes based on 1,8-dihydoxyanthraquinone (DHAQ), as an ionophore, have been developed. Carbon paste electrode has been modified with DAHQ (sensor I), graphene and DHAQ (sensor II) and multi-walled carbon nanotubes (MWCNTs) and DHAQ (sensor III), in order to improve the conductivity and transduction of chemical signal to electrical signal. Under optimized conditions, the electrodes I, II and III revealed Nernstian slopes of 29.78 ± 0.17, 30.25 ± 0.12, and 30.55 ± 0.19 mV decade^-1, respectively, at 25±1 °C covering a wide concentration range from 1×10^–6 to 1×10⁻¹mol L^–1for sensors I and II and from 1×10^–5to 1×10⁻¹ mol L^–1 for sensor III with detection limit values of 8×10⁻⁷, 5×10⁻⁷, and 3.3×10⁻⁶mol L^-1, respectively. The response of the proposed electrodes is very fast and independent of pH in the range of 2.4–6.5 and the response mechanism is studied using IR, SEM and EDX analyses. Selectivity coefficients have been determined by applying separate solution method and matched potential method, where the obtained values indicated the good discrimination of Cu(II) from other cations by the proposed sensors. The developed sensors have been used successfully for quantitative determination of Cu(II) ions in different matrix of spiked real water samples and biological fluids (urine and serum). These sensors have also been used successfully as indicator electrodes in the potentiometric titration of Cu(II) with EDTA. Page(s): 162-173 2020-02-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/54008 Title: Electrochemical immunosensor for the detection of staphylococcal enterotoxin B using screen-printed electrodes Authors: Sharma, Arun; Rao, Vepa Kameswara; Kamboj, Dev Vrat Abstract: Staphylococcal enterotoxin B (SEB) is responsible for large number of food poisoning cases throughout the world. SEB is an exotoxin and it is one of the several harmful substances produced by the bacterium <em>Staphylococcus aureus</em>. Therefore, it is required to develop methods for the sensitive, reliable, reproducible, cheaper, easy to use and rapid detection of SEB. An electrochemical immunosensor has been studied for the fast detection of SEB using disposable screen-printed electrodes. Ascorbic acid-2-phosphate (AA-2P) is used as a new substrate for the voltammetric detection of SEB. In the alkaline buffer solution the alkaline phosphate (ALP) enzymatic hydrolysis product of AA-2P is ascorbic acid (AA). Ascorbic acid is an electroactive substance and gives differential pulse voltammetric oxidative response at +380 mV (versus Ag/AgCl). The potential +0.39 V corresponds to the oxidation of AA. Indirect sandwiched enzyme linked immunosorbent assay (ELISA) has been used for the detection of SEB. In this method, anti-rabbit IgG for SEB (capturing antibody) is first immobilized on the surface of SPE followed by reacting with SEB (antigen) to form antigen-antibody complex. After that, anti-mice IgG for SEB (secondary antibody) are added, followed by ALP-conjugated anti-mice IgG (revealing antibody). The optimal conditions for ALP enzymatic reaction and the volumetric detection have been optimized. It is found that the response of voltammetric immunosensor is proportional to the SEB concentration in the range 0.1–100 ng/mL and the detection limit was found to be 0.1 ng/mL. Page(s): 174-180 2020-02-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/54007 Title: Cordierite honeycomb supported Mo(VI)/ZrO2 for microwave assisted Pinacol-Pinacolone rearrangement Authors: Saritha, S Reena; Shamshuddin, S Z Mohamed; D’Souza, Joyce Q; Mubark, N M Abstract: ZrO₂, Mo(VI)/ZrO₂, SO₄^2-/ZrO₂and Pt-SO₄^2-/ZrO₂ supported on honeycomb monoliths have been prepared and characterized for their physico-chemical properties such as surface acidity, crystalinity, functionality and morphology. These materials have been used as solid acid catalysts in the pinacol rearrangement of benzopinacol under microwave irradiation. A few diols have also been subjected to pinacol rearrangement to obtain a good conversion of rearrangement products with high selectivity. Optimization of reaction conditions has also studied to determine the most suitable reaction conditions for the effective synthesis of pinacolone derivatives. Up to 98% conversion of benzopinacol is observed under a set of optimized reaction conditions. A reactivation and reusability study of zirconia based solid acid catalysts has also performed. Page(s): 181-188 2020-02-01T00:00:00Z