Bioactive supra decorated thiazolidine-4-carboxylic acid derivatives attenuate cellular oxidative stress by enhancing catalase activity.

A pharmacophoric motif decorated with supramolecular functionalities (TZT) was designed for potential interaction with biological targets. Main insights of this work include the correlation of supra functionalities of TZT with its binding ability to proteins leading to the modulation of their structure and bioactivity as a promising perspective in the field of cellular protection from oxidative stress. To investigate the role of TZT in obliterating oxidative stress at a molecular level, its binding propensity with bovine serum albumin (BSA) and bovine liver catalase (BLC) was characterized using various biophysical methods. The binding constants of TZT with BSA (Kb = 2.09 × 105 M-1) and BLC (Kb = 2.349 × 105 M-1) indicate its considerable interaction with these proteins. TZT efficiently triggers favourable structural changes in BLC, thereby enhancing its enzyme activity in a dose dependent manner. The enzyme kinetics parameters of TZT binding to BLC were quantified using the Michaelis-Menten model. Both in silico and experimental results suggest that an increased substrate availability could be the reason for enhanced BLC activity. Furthermore, physiological relevance of this interaction was demonstrated by investigating the ability of TZT to attenuate oxidative stress. Treatment with TZT was found to mitigate the inhibition of A549 cell proliferation in the presence of high concentrations of vitamin C. This finding was confirmed at a molecular level by PARP cleavage status, demonstrating that TZT inhibits apoptotic cell death induced by oxidative stress.

Electrochemical performance of a self-assembled two-dimensional heterostructure of rGO/MoS2/h-BN.

We report the preparation and electrochemical performance evaluation of a two-dimensional (2D) self-assembled heterostructure of graphene oxide (rGO), molybdenum disulphide (MoS2), and hexagonal boron nitride (h-BN). In the present study, the rGO-MoS2-h-BN (GMH) multi-layered GMH heterostructure is fabricated via an in situ chemical route. Based on material analysis, the composite consists of bond conformations of C-B-C, Mo-S, C-N, B-N, and Mo-C, indicating the layered stacks of rGO/h-BN/MoS2. In electrochemical analysis, the composite showed superior performance in the aqueous medium of cobalt sulphate (CoSO4) over other samples. CV measurements, performed over the range 10 to 100 mV s-1, showed a change in specific capacitance (C sp) from 800 to 100 F g-1. GMH showed almost no degradation up to 20 000 cycles @ 100 mV s-1. The calculated C sp, energy density (E D), and power density (P D) are discussed in light of Nyquist, Bode, and Ragone analysis. An equivalent circuit is simulated for the cell and its discrete electronic components are discussed. Due to its larger effective electron diffusion length > 1000 µm, broadly, the composite showed battery-like characteristics, as supported by radical paramagnetic resonance and transport response studies. The symmetric electrodes prepared in one step are facile to fabricate, easy to integrate and involve no pre or post-treatment. They possess superior flat cell character, are cost effective, and are favourable towards practicality at an industrial scale, as demonstrated on the laboratory bench. The details are presented.

Ruthenium-decorated vanadium pentoxide for room temperature ammonia sensing.

Layer structured vanadium pentoxide (V2O5) microparticles were synthesized hydrothermally and successfully decorated by a facile wet chemical route, with ∼10-20 nm sized ruthenium nanoparticles. Both V2O5 and ruthenium nanoparticle decorated V2O5 (1%Ru@V2O5) were investigated for their suitability as resistive gas sensors. It was found that the 1%Ru@V2O5 sample showed very high selectivity and sensitivity towards ammonia vapors. The sensitivity measurements were carried out at 30 °C (room temperature), 50 °C and 100 °C. The best results were obtained at room temperature for 1%Ru@V2O5. Remarkably as short a response time as 0.52 s @ 130 ppm and as low as 9.39 s @ 10 ppm recovery time at room temperature along with high selectivity towards many gases and vapors have been noted in the 10 to 130 ppm ammonia concentration range. Short response and recovery time, high reproducibility, selectivity and room temperature operation are the main attributes of the 1%Ru@V2O5 sensor. Higher sensitivity of 1%Ru@V2O5 compared to V2O5 has been explained and is due to dissociation of atmospheric water molecules on 1%Ru@V2O5 as compared to bare V2O5 which makes hydrogen atoms available on Brønsted sites for ammonia adsorption and sensing. The presence of ruthenium with a thin layer of oxide is clear from X-ray photoelectron spectroscopy and that of water molecules from Fourier transform infrared spectroscopy.

Ecofriendly synthesis and solar photocatalytic activity of S-doped ZnO.

The S-doped ZnO was prepared by new ecofriendly method, which involves simple mechanochemical synthesis followed by thermal decomposition of bisthiourea zinc oxalate (BTZO) powders. The BTZO was characterized by FTIR and TG-DTA analysis while S-doped ZnO crystallite was characterized by XRD, XPS, SEM, EDXS, and photoluminescence (PL) spectra. X-ray diffraction data suggest the single phase wurtzite structure for S-doped ZnO and the incorporation of sulfur expand the lattice constants of ZnO. Room temperature PL spectra show more number of oxygen vacancies in S-doped ZnO as compare to that of pure ZnO. Photocatalytic activity of S-doped ZnO was checked by means of solar photocatalytic degradation (PCD) of resorcinol, using a batch photoreactor. The PCD efficiency of S-doped ZnO was found to be 2 times greater than that of pure ZnO. The inherent relationship between PL intensity and photocatalytic activity of S-doped ZnO was discussed.