Dicle University, Faculty of Arts and Sciences, Dept. of Chemistry, Diyarbakir, Turkey.
J Colloid Interface Sci. 2010 Nov 1;351(1):35-42. doi: 10.1016/j.jcis.2010.07.039. Epub 2010 Jul 21.
Gold nanoparticles (AuNPs) with about 6 nm size were produced and stabilized with mercaptopropionic acid (MPA) film to produce a monolayer protected cluster (MPC) of AuS(CH(2))(2)COOH. 4-Aminothiophenol (ATP) molecules were introduced to the activated carboxylic acid ends of the film surrounding the AuNPs to produce AuS(CH(2))(2)CONHPhSH MPC. These modified AuNPs were again self-assembled with Au@Ag core-shell bimetallic nanoparticles via the -SH groups to produce an organic bridge between Au and Au@Ag metallic nanoparticles. An unusually strong enhancement of the Raman signals was observed and assigned to the plasmon coupling between the AuNPs and Au@Ag NPs bridged assembly. Formation of AuS(CH(2))(2)COOH and AuS(CH(2))(2)CONHPhSH clusters and AuS(CH(2))(2)CONHPhS(Au@Ag) assembly is confirmed by UV-Vis, reflection-absorption IR spectroscopy (RAIRS) and X-ray photoelectron spectroscopy (XPS), as well as by TEM analysis. The SERS activity of the AuNPs and Au@Ag NPs was tested using the HS(CH(2))(2)CONHPhSH molecule as a probe to compare the effectiveness of monometallic and bimetallic systems. SERS spectra show that Au@Ag bimetallic nanoparticles are very effective SERS-active substrates.
制备了约 6nm 尺寸的金纳米粒子 (AuNPs)，并用巯基丙酸 (MPA) 薄膜稳定，以产生单层保护的 AuS(CH(2))(2)COOH 簇 (MPC)。将 4-巯基苯并噻酚 (ATP) 分子引入到围绕 AuNPs 的薄膜的活化羧酸末端，以产生 AuS(CH(2))(2)CONHPhSH MPC。这些修饰的 AuNPs 再次通过 -SH 基团自组装成 Au@Ag 核壳双金属纳米粒子，以在 Au 和 Au@Ag 金属纳米粒子之间产生有机桥。观察到 Raman 信号异常增强，并归因于 AuNPs 和 Au@Ag NPs 桥接组装之间的等离子体耦合。AuS(CH(2))(2)COOH 和 AuS(CH(2))(2)CONHPhSH 簇以及 AuS(CH(2))(2)CONHPhS(Au@Ag) 组装的形成通过紫外-可见光谱、反射吸收红外光谱 (RAIRS) 和 X 射线光电子能谱 (XPS) 以及 TEM 分析得到证实。使用 HS(CH(2))(2)CONHPhSH 分子作为探针测试了 AuNPs 和 Au@Ag NPs 的 SERS 活性，以比较单金属和双金属系统的有效性。SERS 光谱表明，Au@Ag 双金属纳米粒子是非常有效的 SERS 活性衬底。
