Sonochemical Synthesis of Graphene Oxide-Wrapped Gold Nanoparticles Hybrid Materials:Visible Light Photocatalytic Activity

Graphene oxide(GO)-wrapped gold nanoparticles(Au NPs)hybrid materials are constructed via one-pot sono-chemical synthesis and self-assembly,using ethylene glycol as the reducing agent.The synthesis process above took only 1 h,and the obtained hybrid materials exist as spheres wrapped with gauze-like GO sheets via ionic in-teraction-based self-assembly.The GO sheets are helpful for the well dispersion of the Au NPs.Furthermore,these materials possess enhanced photocatalytic activity under visible light irradiation,owing to the synergistic effect of the two components in the hybrid materials.Our work may provide a convenient approach to control the size and morphology of the Au NPs for the synthesis of GO-wrapped hybrid materials,which opens up a feasible way to synthesize metal NPs/GO composites.Moreover,this method might lead to developing of a broad class of new functionalized materials wrapped with GO sheets.

Sodium Citrate： A Universal Reducing Agent for Reduction/ Decoration of Graphene Oxide with Au Nanoparticles

A facile method is proposed for the synthesis of reduced graphene oxide nanosheets （RGONS） and Au nanoparticle-reduced graphene oxide nanosheet （Au-RGONS） hybrid materials, using graphene oxide （GO） as precursor and sodium citrate as reductant and stabilizer. The resulting RGONS and Au-RGONS hybrid materials were characterized by UV-vis spectroscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, atomic force microscopy, transmission electron microscopy, and X-ray diffraction. It was found that the RGONS and Au-RGONS hybrid materials formed stable colloidal dispersions through hydrogen bonds between the residual oxygen-containing functionalities on the surface of RGONS and the hydroxyl/carboxyl groups of sodium citrate. The electrochemical responses of RGONS and Au-RGONS hybrid material-modified glassy carbon electrodes （GCE） to three kinds of biomolecules were investigated, and all of them showed a remarkable increase in electrochemical performance relative to a bare GCE.

石墨烯/铂纳米粒子杂化膜测定肾上腺素

利用循环伏安法制备了石墨烯/铂纳米粒子杂化膜修饰电极,并利用该修饰电极研究了肾上腺素（EP）的电化学行为,建立了测定肾上腺素的电化学方法。分别利用扫描电子显微镜和循环伏安法对电极的表面形貌和电化学性能进行了表征,优化了修饰电极制备过程中影响电极性能的条件和EP的测定条件。结果表明,石墨烯/铂纳米粒子修饰电极对肾上腺素有明显的电催化作用。在p H=5.0的柠檬酸-磷酸氢二钠缓冲溶液中,EP的氧化峰电流与其浓度在4.4×10^-8~2.2×10^-6mol/L的范围内呈良好的线性关系。线性方程为ipa（10 A）=0.0753c（mol/L）＋3.7653×10^-5,r=0.9989,检出限为2.2×10^-9mol/L（S/N=3）。修饰电极表具有良好的重现性,可用于实际样品的测定。

石墨烯及其衍生物/金纳米粒子复合材料的表面增强拉曼散射研究进展

由于石墨烯及其衍生物/金纳米粒子复合材料可以产生剧烈的表面增强性拉曼散射(SERS),因而被广泛应用到医学检验、环境监测和生物化学等领域。基于这种新型的复合材料,首先从复合材料SERS的增强机制出发,系统介绍了其电磁场增强机制和化学增强机制。随后,阐述了基于石墨烯及其衍生物/金纳米粒子复合材料的国内外SERS研究现状。最后,展望了石墨烯及其衍生物/金纳米粒子复合材料在各个领域的应用前景。

氧化石墨烯/金银纳米粒子复合材料的制备及其SERS效应研究

近年来,氧化石墨烯/金银纳米粒子复合材料由于其优异的表面增强拉曼散射(SERS)性能引起了人们极大的关注,在污染物检测、化学传感和癌症诊断等领域具有重要的应用价值。本文综述了氧化石墨烯片层上修饰金银纳米粒子、氧化石墨烯包覆金银纳米粒子、氧化石墨烯附着在金银纳米粒子层三种氧化石墨烯/金银纳米粒子复合材料的制备方法,对其SERS效应进行了详细介绍。SERS研究表明,结合了金银纳米粒子与氧化石墨烯两种材料各自在SERS研究与应用中的优势,氧化石墨烯/金银纳米粒子复合材料的SERS性能比单纯金银纳米粒子更加优异。氧化石墨烯在其中起到了化学增强、分子富集、钝化保护、荧光猝灭的重要作用。氧化石墨烯/金银纳米粒子复合材料在表面增强拉曼光谱中具有广阔的应用前景。