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Lead containing calcium zinc sodium fluoroborate glasses (LCZSFB) with molar composition of 20PbO+5CaO+5ZnO+10NaF+(60−x) B2O3+x Sm2O3, (x=0.1, 0.25, 0.5, 1.0 and 2.0 mol%) were prepared and investigated by the XRD, FTIR, optical absorption, photoluminescence and decay curve analysis. Judd–Ofelt theory was applied to the experimental oscillator strengths to evaluate the phenomenological J–O intensity parameters Ωλ (λ=2, 4 and 6). Using the J–O intensity parameters as well as from the emission and decay measurements, various radiative parameters such as transition probabilities (AR), radiative lifetimes (τR), measured lifetimes (τm), calculated branching ratios (βR), measured branching ratios (βm), effective bandwidth (Δλeff) and stimulated emission cross sections σ(λp) have been calculated for the excited 4G5/2 luminescent level. The nature of decay curves of 4G5/2 level for different Sm3+ ion concentrations in all LCZSFB glasses has been analyzed and the lifetimes are noticed to decrease with increase of concentration. The concentration quenching has been attributed to the energy transfer through the cross-relaxation between Sm3+ ions. Based on these results, the utility of Sm3+ ions doped lead containing fluoroborate glasses as laser active materials in the visible region is discussed.

Bio-based green nanotechnology aims to characterize compounds from natural sources and establish efficient routes for the preparation of nontoxic materials that have applicability in biodegradable and biocompatible devices. The present study has investigated the use of Plectranthus amboinicus leaf extracts as reducing and capping materials for the green fabrication of silver, gold, and silver-gold (Ag, Au, and Ag/Au) metal and bimetallic nanoparticles. The catalytic behavior of these phyto-inspired nanoparticles was then assessed in terms of the reduction of 4-nitrophenol. Transmission electron microscopy was used to investigate the shape, morphology, distribution, and diameter of the phytomolecules capped with Ag, Au, and Ag/Au metal nanoparticles. The nature of the crystallinity of the nanoparticles was studied by small area electron diffraction (SAED) and x-ray diffraction analysis (XRD), and Fourier transform infrared (FTIR) spectroscopy was used to study the reduction and stabilizing involvement of the phyto-organic moieties in aqueous medium. The phyto-inspired Ag and Ag/Au nanoparticles demonstrated good antibacterial properties toward Gram-negative Escherichia coli and Pseudomonas spp. and Gram-positive Bacillus spp. and Staphylococcus spp. microorganisms using the well diffusion method. Notably, the Ag nanoparticles were shown to possess effective antibacterial properties.

The use of biomolecules hosted products for synthesis of nano sized materials of increasing interest to benign medicinal field. We report a biomolecules hosting, rapid, environmentally benign, bio-degradable, non-toxic, and sonochemical synthesis of gold nanoparticles by using piper betle leaf broth as a reducing and capping agent. The aqueous reaction of medium containing gold nanoparticles showed a peak at 540 nm was studied by UV-Vis spectra. In addition, we determined the size of the nanoparticles and optical energy gap from the surface plasmon absorption peak. The crystalline structural characteristics of a biomolecules hosted gold nanoparticles were studied by X-ray diffraction. The morphology of nanoparticles was analyzed by scanning electron microscopy. The stoichiometric chemical composition of elemental presence in the medium was determined by energy dispersive spectrum. The presences of biomolecules which are act as capping agents around the nanoparticles were studied by fourier transform infrared spectroscopy.

TiO 2 thin films were synthesized by using DC reactive magnetron sputtering technique and their use in the photocatalytic degradation of a model compound - Rhodamine B - by ultraviolet (UV) irradiation was studied. In this investigation, the effect of post deposition annealing on structural, morphological, optical and photocatalytic behaviour of TiO 2 films was examined. Spectroscopic techniques like XRD, Raman, XPS, Optical transmittance and FTIR were used to characterize thinfilms. The surface morphology of the thin films was observed by AFM analysis. The variation in photocatalytic activity of TiO 2 thin films with annealing temperature as varying parameter was examined by optical absorption studies. The photocatalytic activity of the thin films was found to increase with annealing which can be attributed to the growth of anatase phase in the thin film upon annealing.

A novel chemically modified electrode was constructed based on the electrodeposition of palladium nanoparticles (PdNps) on to a poly(solochrome cyanine) (polySCCy) film coated carbon paste electrode (CPE). Cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS) were used to characterize the properties of the modified electrode. The polySCCy/PdNPs/CPE was used for the impressionable, individualized determination and simultaneous resolution of dopamine (DA), ascorbic acid (AA) and uric acid (UA) in 0.1 M acetate buffer solution (ABS) of pH 5.0 by employing CV and DPV. The polySCCy/PdNPs/CPE exhibited strong electrocatalytic activity towards the oxidation of a mixture solution of DA, AA and UA with obvious redox potentials. The overlapping voltammetric response of biomolecules were separated into three well resolved oxidation peaks for DA, AA and UA with lower oxidation potentials and significant increase in the anodic peak currents in the presence of polySCCy/PdNPs/CPE by using CV and DPV. The results showed good sensitivity, selectivity and high reproducibility of the electrosynthesized polymer nanoparticles inclusion electrode. The limit of detection, limit of quantification and correlation coefficient of DA at polySCCy/PdNPs/CPE were 1.87 μM, 6.24 μM and 0.99375, respectively. The developed chemical sensor is ideal for the analysis of DA in pharmaceutical formulations providing satisfactory results. The interfacial electron transfer rate of DA was studied by EIS.

Facile approach to synthesize the metal oxide nanoparticles is getting an increased attention in various biomedical applications such as, to treat antibiotic resistant diseases. Magnesium oxide nanoparticles (MgO·NPs) were synthesized by using Clitoria ternatea as the stabilizer in a green synthesis approach. The preliminary screening of MgO·NPs in the presence of C. ternatea extract was observed by UV–visible spectrophotometer. X-ray diffraction (XRD) pattern have proved the crystalline nature of the MgO·NPs; Photoluminescence (PL) measurement studies are used to identify the quality and defects in the crystal structure. FE-SEM with EDS has showed the size of 50–400 nm with specific binding energies. FT-IR has revealed the functional groups present in the plant extract and the peak at 521 cm−1 indicated the characteristic absorption bands of MgO·NPs. The DPPH activity and reducing power assay of biologically synthesized MgO·NPs could reach 65 % at a concentration of 150 µg/ml, respectively. From the results it was concluded that the biologically synthesized MgO·NPs exhibit good antioxidant activity.