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Gold nanoparticles (AuNPs) were prepared by UV-irradiation technique at different irradiation times. Polyvinyl alcohol with two different molecular weights was used as encapsulating agent. The PVA capped gold nanoparticles showed surface plasmon bands at 531 nm after 1 h UV-irradiation and emission band at 365 nm and 394 nm with an excitation wavelength 300 nm. TEM micrograph showed that majority of the AuNPs are spherical, some are hexagonal, triangular and rod shaped. The XRD study clearly indicates formation of AuNPs. The preferential growth along (111) plane is also evident from XRD and has supported the results obtained from HRTEM analysis. The FTIR study suggested that interaction between AuNPs and the polymer matrix takes place through O-H groups. It was found that not only concentration and molecular weight of PVA but also irradiation time play important role in the formation of AuNPs. Antibacterial activity of AuNPs, Gentamicin and Gentamicin-AuNPs mixture against Bacillus Subtilis was examined by the agar well diffusion method. The antibacterial activity of Antibiotic-AuNPs mixture was found to be higher than that of pure antibiotic. Antibacterial activity showed that AuNPs can act as an effective drug carrier in drug delivery system.

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II-VI semiconductor based ternary CdMnS compound material has received more attention due to its wide area of applications in semiconductor technology. Cd1 -xMnxS (x  0, 0.2, 0.4, 0.6, 0.8 and 1.0) thin films were successfully prepared by chemical bath deposition technique on non-conducting glass substrates. Thin films were deposited at a bath temperature of 80 C and pH  11 by using the chemical bath reaction of cadmium chloride (CdCl2) and manganese chloride (MnCl2) with thiourea (NH4)2S in an aqueous solution. Further, the prepared samples were characterized by UV-visible spectroscopy, photoluminescence, XRD, SEM and EDAX to study the optical, structural, surface, and chemical properties. Effect of Mn 2+ ions on the film thickness of Cd1 -xMnxS films was investigated using weight difference technique. The film thickness of Cd1 -xMnxS films decreases as Mn 2+ ions increase in the bath solution. The polycrystalline nature with hexagonal and cubic structures of the as-deposited films was confirmed by XRD. The band gap value of the deposited films was observed to increase with increasing Mn 2+ ion concentration, this might be ascribed to the fact that Cd atom was substituted by Mn atom in the CdS structure. EDAX analysis confirmed the deposition of Cd, Mn and S elements in the films. Photoluminescence spectra of Cd1 -xMnxS with different values of the composition parameter x exhibited two emission peaks with different intensities. The measurement of the electrical resistivity of Cd1 -xMnxS films was performed at room temperature using two probe methods. The variation in electrical resistivity values with compositional parameters was discussed based on deposition parameters. The investigated polycrystalline Cd1 -xMnxS thin films show promising technological applications in semiconductor industry.

Semiconducting thin films of ternary Hg Cr 2− S 4 ( = 0.4) have been deposited on glass substrate by the simple and economical chemical bath deposition method. We report the deposition and optimization of the solution growth parameters such as temperature, complexing agent, thiourea, and deposition time that maximizes the thickness of the deposited thin film. The Xray diffraction deposited Hg Cr 2− S 4 thin films having cubic structure. The thin films were uniform and adherent to substrate. The composition was found homogeneous and stoichiometric by EDAX analysis.