Publications

The sol-gel process was used to create a new type of polypyrrole-Stannous(II)tungstate nanocomposite by poly(N-methyl pyrrole (PNMPy) sol in Stannous(II)tungstate gel, produced separately using sodium silicotungstic acid and Tn(II)chloride. Tin(II)tungstate (SnWO3) was made by changing the mixing volume ratios of SnWO3 and with a constant amount of an organic polymer. The composite was characterized by TGA, XRD, FTIR, and SEM measurements. A commercially available glassy carbon electrode (GCE) was modified with PNMPy/nano-Stannous(II)WO3 nanocomposites to create a chemical sensor for selective detection of Hg2+ ions using an effective electrochemical methodology. In the I-V technique, selectively toxic Hg2+ ion was targeted selectively, which shows a rapid reaction toward PNMPy/nano-Stannous(II)WO3/Nafion/GCE sensor. It also demonstrates long-term stability, an ultra-low detection limit, exceptional sensitivity, and excellent reproducibility and repeatability. For 0.1 mM to 1.0 nM aqueous Hg2+ ion solution, a linear calibration plot (r2: 0.9993) was achieved, with a suitable sensitivity value of 2.8241 AM−1 cm−2 and an extraordinarily low detection limit (LOD) of 3.40.1 pM (S/N = 3). As a result, the cationic sensor modified by PNMPy/nano-Stannous(II)WO3/GCE could be a promising electrode.

Environmental pollution is one of the global hot issues and need an urgent demand to detect and monitor the pollutants which affect the environment. Ammonia is one of the organic pollutants which cause severe harmful effect on environment due to its toxic nature. Therefore, electrochemical sensor has been fabricated using CeO2 nanoparticles (NPs) as a redox mediator to detect aqueous ammonia for environmental safety. The electrical response of the ethanol sensor was investigated by I-V technique which exhibited high sensitivity (0.3519 μA.cm-2.mM-1) and lower limit of detection (LOD = 0.395 μM). CeO2 nanoparticles were synthesized hydrothermally at low temperature and field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), and Raman spectroscopy corroborated that the synthesized product is aggregated form of spherical nanoparticles, well crystalline possessing cubic phase with an average size of ~ 50 ± 10 nm. UV-Visible absorption spectrum confirmed that CeO2 nanoparticle is optically active with absorption band of 297 nm. Keywords: CeO2 nanoparticles, Structural properties, Optical properties, Ammonia chemi-sensor

Abstract Herein, the cloud points (CPs) of tween 80 (Tw 80) in water/(water + diols [ethanediol, propanediol, and butanediol])/(water + polyols [glucose, fructose, and sorbitol]) systems were measured. For diols‐Tw 80‐water system and polyols‐Tw 80‐water system, the CP values were obtained to reduce gradually with increasing content of diols and polyols at a particular concentration of Tw 80. For a certain concentration of Tw 80 having different contents of diols, the observed ∆ H 0 c , as well as ∆S 0 c values, were negative over the range of concentration of diols studied, and the negative values of ∆ H 0 c and ∆ S 0 c were reduced with the enhancement of the content of diols. The values of ∆ H 0 c were negative, which indicate the process was exothermic. The clouding process of Tw 80 in the presence of different diols is mainly enthalpy‐controlled process, while the contributions of enthalpy tend to reduce with enhancing of the contribution of diols. In the case of polyols‐Tw 80 mixture in an aqueous environment, the ∆ G c 0 values were achieved positive. The values of ∆ H c 0 and ∆ S c o were obtained negative for studied systems, while the negative values reduce with enhancing of polyol (glucose and fructose) concentrations. For sorbitol‐Tw 80 system, the values of ∆ H c 0 were observed to be negative and the negative magnitudes reduce with enhancing of sorbitol concentrations. The thermodynamic parameters of transfer are also evaluated and illustrated in detail.

Polyaniline-grafted-GO@WO₃was prepared and deposited on a Ag electrode with conducting binders to give a sensor with a fast selective response for Cr³⁺in the liquid phase. The sensitivity and detection limit are ∼4.4251 mA mM⁻¹cm⁻²and 0.031 ± 0.010 nM.

The petroleum ether extract of the red alga Laurencia obtusa afforded three new C(15) acetogenins (cyclic ether enyne): (12Z)-cis-maneonene-D (1), (12E)-cis-maneonene-E (2), and (12Z)-trans-maneonene-C (3), along with one known cis-maneonene-A (4). Blood neutrophils were prepared, cultured, and incubated for 24, 48, and 72 h in medium with and without isolated compounds. Blood neutrophils were prepared, cultured, and incubated for 24, 48 and 72 h in medium with and without the isolated compounds. Both morphology and DNA fragmentation methods assessed the percentage of neutrophils apoptosis in each culture. In the present study, several observations have been made concerning the apoptosis-inducing or inhibiting effect of 1 and 2. Both compounds had no inhibition of apoptosis but apoptosis was enhanced significantly by aging. However, 1 stimulated apoptosis of normal only at the initial 24 h. After that there was no significant difference in apoptosis with or without compound 1, while 2 stimulated apoptosis at all the times. The apoptosis induced by these two compounds was demonstrated by DNA fragmentation assay and microscopic observation. These observations suggest that compounds 1 and 2 may be involved in regulation of programmed death in the initiation and propagation of inflammatory responses.