No abstract

No abstract

Synthesis of silver nanoparticles (AgNPs) usingPolyalthia longifolialeaf extract as reducing and capping agent along with D-sorbitol used to increase the stability of the nanoparticles has been reported. The reaction is carried out at two different concentrations (10−3 M and 10−4 M) of silver nitrate, and the effect of temperature on the synthesis of AgNPs is investigated by stirring at room temperature (25°C) and at 60°C. The UV-visible spectra of NPs showed a blue shift with increasing temperature at both concentrations. FT-IR analysis shows that the biomoites played an important role in the reduction of Ag+ions and the growth of AgNPs. TEM results were utilized for the determination of the size and morphology of nanoparticles. The synthesized silver nanoparticles are found to be highly toxic against Gram-positive bacteria than Gram-negative bacteria.

Pdnp and Pd containing trimetallic nanoparticles (tnp) are synthesized by chemical method with cetyltrimethylammonium bromide as the capping agent. Compositionally, four different tnp are prepared and the particle sizes are characterized by UV-vis spectra, HR-TEM, and XRD measurements. The catalytic activities of Pdnp and tnp are tested using the Sonogashira C-C coupling reaction. The product yield and recyclability of the recovered catalysts are studied. tnp (1:1:1) exhibited better catalysis than Pdnp, which may be due to the concerted electronic effects of the Au-Ag core onto the Pd shell atoms.

Small angle neutron scattering (SANS) measurements of D 2 O solutions (0⋅1 M) of sodium cholate (NaC) and sodium deoxycholate (NaDC) were carried out at T = 298 K. Under compositions very much above the critical micelle concentration (CMC), the bile salt micelle size growths were monitored by adopting Hayter-Penfold type analysis of the scattering data. NaC and NaDC solutions show presence of correlation peaks at Q = 0⋅12 and 0⋅1 Å-1 respectively. Monodisperse ellipsoids of the micelles produce best fits. For NaC and NaDC systems, aggregation number (9⋅0, 16⋅0), fraction of the free counterions per micelle (0⋅79, 0⋅62), semi-minor (8⋅0 Å) and semi-major axes (18⋅4, 31⋅7 Å) values for the micelles were deduced. Extent of micellar growth was studied using ESR correlation time measurements on a suitable probe incorporating NaC and NaDC micelles. The growth parameter (axial ratio) values were found to be 2⋅3 and 4⋅0 for NaC and NaDC systems respectively. The values agree with those of SANS.

No abstract

No abstract

In this work, the gold nanoseed mediated growth of bullet-like gold-zinc oxide (Au-ZnO) heterodimer nanoparticles has been reported. A formation pathway for the bullet-like morphology has been proposed. The heterojunction effect of the Au-ZnO nanoparticles was studied using UV-vis spectroscopy, X-ray photoelectron spectroscopy (XPS), high resolution transmission electron microscopy (HRTEM) and electrochemical impedance spectroscopy (EIS). The bullet-like Au-ZnO heterodimer nanoparticles were effectively employed as a sensor for the nonenzymatic determination of glucose (GLU) in a Au-ZnO/MWCNTs/GC modified electrode. This showed good sensitivity and a wide linear range of 19-291 mM with a sensitivity of 0.0447 mA mM À1 and a limit of detection of 0.19 mM. The resulting sensor displayed excellent repeatability and long-term stability.