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The chain-like NiWO 4 nanomaterials on DNA scaffold were characterized using several spectroscopic techniques. The UV-Visible (UV-Vis) absorption spectra were recorded in a double beam spectrophotometer purchased from Unico (model 4802 UV-Vis spectrophotometer). The transmission electron microscopy (TEM) analysis was done with a Tecnai model TEM instrument (TecnaiTM G2 F20, FEI) with an accelerating voltage of 200 KV. The Field Emission Scanning Electron Microscopy (FE-SEM) analysis was recorded with Zeiss ultra FE-SEM instruments. The Energy Dispersive X-ray Spectroscopy (EDS) analysis was done with the same FE-SEM instrument with a separate EDS detector (INCA) connected to that instrument. The X-ray diffraction (XRD) analysis was done using a PAN analytical Advanced Bragg-Brentano X-ray powder diffractometer (XRD) with Cu Kα radiation (λ = 0.154 nm) with a scanning rate of 0.020 s -1 in the 2θ range 10-90°. The X-ray photoelectron spectroscopic (XPS) analysis was done to check the chemical composition and the state of elements present in the outermost part of materials and analyzed by using Theta Probe AR-XPS System, Thermo Fisher Scientific (U.K). The LASER Raman measurements were carried out with Renishaw inVia Raman Microscope using an excitation wavelength of 632.8 nm (He-Ne laser). The excitation light intensity in front of the objective was ~10 mW with a spectral collection time of 1 sec for Raman experiment. The integration time for our measurement was set to 10 sec. The photoluminescence (PL) study was done with Varian

A new route for the formation of osmium nanoparticles (NPs) having different morphologies like aggregated clusters, chain-like networks, and small spheres are reported. The synthesis was done by utilizing a simple wet-chemical method at room temperature (RT) by the reaction of OsO 4 , cetyl trimethyl ammonium bromide (CTAB), 2,7-dihydroxynaphthalene (2,7-DHN) and NaOH under 30 min of reaction. The diameter of the individual particles in all the morphologies was B1-3 nm. The synthesized materials have been tested for catalysis and SERS studies. The catalysis study was examined taking different organic nitro compounds and the catalysis rate was found superior as compared to other reports. The surface enhanced Raman scattering (SERS) study was done taking Rose Bengal (R Be) as a probe molecule and the observed enhancement factor (EF) value was found superior or comparable to most of other noble metal NPs. The overall synthesis process was simple, less time consuming and cost-effective. The enhanced catalytic and SERS activities of the Os NCs might open up a new avenue for the application in other organic catalysis reactions, SERS based detection of environmentally important trace bio-molecules and sensors.

À1 at 5 mV s À1 was observed for the flake-like structure, which is higher compared to that of the wire-like structure. The flake-like MnO 2 nanostructure exhibited an excellent long-term stability, retaining 81% of initial capacitance even after 4000 cycles, whereas for the wire-like MnO 2 nanostructure, capacitance decreased and the retention value was only 70% over 4000 cycles. In the future, the present approach can be extended for the formation of other oxide-based materials using DNA as a promising scaffold for different applications such as homogeneous and heterogeneous organic catalysis reactions, Li-ion battery materials or for the fabrication of other high performance energy storage devices.

Osmium (Os) organosol on DNA scaffold has been synthesized by utilizing a homogeneous reduction route. The synthesis was done by the reduction of OsO4 with tetrabutylammonium borohydride (TBABH4) in the presence of DNA in acetone within 10 min of stirring at room temperature. Different morphologies were synthesized by varying the DNA to OsO4 molar ratio and controlling the other reaction parameters. The eventual diameters of the individual Os particles in organosol were ∼1–3 nm, and the nominal lengths of the wires were ∼1–2 μm. The potentiality of the Os organosol was tested in two different applications: one is the catalytic hydrogenation of cyclohexene to cyclohexane and other is the surface enhanced Raman scattering (SERS) studies. The SERS study has been examined using MB as a Raman probe, and the EF value is found to be the highest in the case of Os organosol having aggregated wires (short size) compared to longer wires. The fast synthesis of Os organosol on DNA and their potential catalytic and SERS activity will be found to be very useful in the near future for the catalytic applications of various organic reactions and in the fields of sensors, electronic devices, and fuel cells.