模板法合成金属-分子-金属异质结及表面增强拉曼光谱研究

Template Preparation of Metal-Molecule-Metal Junction and Its SERS Investigation

采用交流电沉积技术在阳极氧化铝(AAO)模板中沉积不同的金属纳米线,以对巯基苯(1,4-BDT)为耦联分子,通过自组装在模板内组装金属纳米粒子,由此构建金属纳米线-分子-金属纳米粒子的异质结。以异质结内的分子为探针,采用表面增强拉曼光谱(SERS)研究了异质结的增强行为,通过探针分子的SERS信号表达异质结的组成,并以异质结作为模型研究其SERS机理。研究结果表明该方法可成功构建异质结,同一取向的异质结的SERS信号较随机取向的SERS信号强。

In the present paper, the authors reported the assembly and SERS studies of a simple device unit of a metal nanowiremolecule-metal nanoparticles junction in an anodic aluminum oxide （AAO）template. The AAO template was fabricated by twostep electrochemical oxidation. Metals were filled into the pores by AC deposition. Then the AAO template with metal nanowires was immersed into the solution of 1,4-benzenedithiol （ 1,4-BDT）, which was followed by the immersion into silver nanoparticles with appropriate diameter. 1,4-BDT served as the probe molecule for SERS detection as well as the molecule for linking the metal nanowires and metal nanoparticles. The simple junction of metal-molecule-metal embedded in AAO template was built successfully. The SERS effect of the junction was investigated through the dissolution of AAO template to expose the junctions in the same orientation （standing on the substrate vertically）. The giant enhancement from the former junction might be attributed to the coupling effect in the junction. The authors＇ preliminary results revealed that SERS might be a characteristic tool for the junction and the construction on the junction will be beneficial to the investigation of the complex SERS mechanism.