No abstract

Investigation into the interactions between biomolecules DNA/RNA and carbon nanomaterials is very important for applications in bioassays and bioanalysis. Graphene and graphene oxide (GO) have been successfully adopted by exploiting the binding affinity difference between single-stranded oligonucleotides (ssDNA) and double-stranded oligonucleotides (dsDNA) to graphene sheets. In this work, we describe the electrochemical DNA oxidation with [Ru(bpy) 3 ] 2+ to understand the interaction between dsDNA (and corresponding ssDNA) and reduced graphene oxide (rGO). The electrochemical oxidation rate of guanine bases of ssDNA bound to rGO by electrochemically generated [Ru(bpy) 3 ] 3+ was much slower than those unbound to rGO. Our study revealed that ssDNA constrained on rGO was significantly protected from the electron transfer to [Ru(bpy) 3 ] 3+ because of π,π-stacking interaction between nucleobases and rGO. On the other hand, the oxidation rates of 11-, 20-, and 27-mer dsDNA bound to rGO increased relative to those of dsDNA alone, demonstrating that the guanine bases of dsDNA on the interaction with rGO became more accessible to [Ru(bpy) 3 ] 3+ . Our electrochemical data illustrated that dsDNA could be totally or partially dehybridized and bind to rGO to form ssDNA/rGO. Furthermore, absorption, circular dichroism spectra, and fluorescence measurements of ethidium bromide using ssDNA and dsDNA with rGO supported the dehybridization of dsDNA in the presence of rGO.

A gold nanoparticle solution was prepared by adding sodium borohydride (NaBH4), trisodium citrate dihydrate (C6H5Na3O7·2H2O), cetyltrimethyl ammonium bromide (CTAB,(C16H33)N(CH3)3Br), ascorbic acid (C6H8O6), and potassium tetrachloroaurate(III)(KAuCl4) to distilled water and stirring the solution for 15 min. [C60]fullerene nanowhisker-gold nanoparticle composites were synthesized using C60-saturated toluene, the gold nanoparticle solution, and isopropyl alcohol by liquid-liquid interfacial precipitation (LLIP). The product of the nanocomposites was characterized by X-ray diffraction, scanning electron microscopy, Raman spectroscopy, transmission electron microscopy, and solid-state 13C-nuclear magnetic resonance spectroscopy. The catalytic activity of the [C60]fullerene nanowhisker-gold nanoparticle composites was confirmed in 4-nitrophenol reduction by UV-vis spectroscopy.

No abstract

No abstract

No abstract

No abstract

Synthesis of hybrid carbon-nickel (C-Ni) nanocomposite was performed with [C 60 ] fullerene and Ni hydroxide in an electric furnace at 700°C for 2 h. The resulting product was characterised by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, transmission electron microscopy, and electron spin resonance spectroscopy. The catalytic reduction of 2-nitrophenol using the hybrid nanocomposite was investigated by ultraviolet-visible spectroscopy. Kinetic study showed that reduction of 2-nitrophenol in the presence of sodium borohydride with the hybrid C-Ni nanocomposite was followed a pseudo-first-order reaction law.