Publications

As-grown ZnO-Fe2O3 microwires were prepared by a wet-chemical process using reducing agents in alkaline medium and characterized by UV/vis., FT-IR, Raman, electron-dispersive (EDS) spectroscopy, powder X-ray diffraction (XRD), and field-emission scanning electron microscopy (FESEM). They were deposited on a gold electrode (AuE, surface area, 0.0216 cm2) to fabricate a chemi-sensor with a fast response towards toxic phenyl hydrazine (PhHyd) chemical in phosphate buffer solution (PBS). The chemi-sensor was also exhibited higher sensitivity and long-term stability, 2 and enhanced electrochemical response towards toxic PhHyd. The calibration plot was linear (r2 = 0.9389) over the 1.0 nM to 10.0 mM PhHyd concentration ranges. The sensitivity and detection limit were calculated about 8.33 μAcm-2mM-1 and 0.67 ± 0.05 nM (signal-to-noise ratio, at a SNR of 3) respectively. Here the possible future prospective uses of the ZnO-Fe2O3 microwires in terms of chemical sensing are discussed.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Abstract In this study, plant-mediated copper nanoparticles (CuNPs) were synthesized. Due to its direct synthesis mechanism and eco-friendly nature, the current method accounts for the green chemistry approach using the fruit extract of Duranta erecta for the first time. The UV-visible spectrum of the CuNPs solution showed a distinct absorption peak at 588 nm. Fourier transform infrared spectroscopy confirmed that the fruit extract is responsible for the reduction as well as the stabilization of CuNPs. X-ray diffraction patterns conform the crystalline nature of CuNPs. Energy-dispersive X-ray spectroscopy was performed for elemental analysis whereas field emission scanning electron microscopy was carried out for surface morphology. Prepared CuNPs were used for the reduction of carcinogenic azo dyes methyl orange (MO) and congo red (CR). CuNPs exhibit outstanding catalytic reduction for MO and CR in the presence of NaBH 4 as reducing agents with the pseudo-first-order rate constants of 8.6×10 −3 s −1 and 5.07×10 −3 s −1 for MO and CR, respectively. Thus, natural plant materials act as cheap and environmentally friendly support for the synthesis of CuNPs and could be used for the purification of water from organic dye effluents.

Dimerization-macrocyclization has been a long-standing problem in the cyclization of peptides since, together with the desired cyclic product, many cyclic oligomers and linear polymers may also be formed during the reaction. Therefore, the development of a process that affords the cyclic dimer predominantly is difficult. A novel and versatile strategy for the synthesis of symmetric cyclo-tetrapeptides by palladium-promoted tandem deprotection/cyclo-dimerization from readily available Cbz-dipeptidoyl benzotriazolides is reported (Cbz=carboxybenzyl).

The development of a sensitive glucose monitoring system is highly important to protect human lives as high blood-glucose level-related diseases continue to rise globally. In this study, a glucose sensor based on polyaniline-bimetallic oxide (PANI-MnBaO₂) was reported. PANI-MnBaO₂ was electrochemically synthesized on the glassy carbon electrode (GCE) surface. The as-prepared PANI-MnBaO₂ was characterized by field emission scanning electron microscopy, Fourier transform infrared spectroscopy, energy dispersive X-ray spectroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. Glucose sensing on PANI-MnBaO₂ is based on the electrocatalytic oxidation of glucose to the glucolactone, which gives oxidation current. The oxidation potential for glucose was 0.83 V, with a limit of detection of 0.06 µM in the linear and in the concentration range of 0.05 µM-1.6 mM. The generated current densities displayed excellent stability in terms of repeatability and reproducibility with fast response. The development of a sensitive glucose sensor as obtained in the current study would ensure human health safety and protection through timely and accurate glucose detection and monitoring.