Ward Daniel R, Halas Naomi J, Ciszek Jacob W, Tour James M, Wu Yanpeng, Nordlander Peter, Natelson Douglas
Department of Physics and Astronomy, Rice Quantum Institute, Rice University, 6100 Main Street, Houston, Texas 77005, USA.
Nano Lett. 2008 Mar;8(3):919-24. doi: 10.1021/nl073346h. Epub 2008 Feb 1.
Electronic conduction through single molecules is affected by the molecular electronic structure as well as by other information that is extremely difficult to assess, such as bonding geometry and chemical environment. The lack of an independent diagnostic technique has long hampered single-molecule conductance studies. We report simultaneous measurement of the conductance and the Raman spectra of nanoscale junctions used for single-molecule electronic experiments. Blinking and spectral diffusion in the Raman response of both p-mercaptoaniline and a fluorinated oligophenylyne ethynylene correlate in time with changes in the electronic conductance. Finite difference time domain calculations confirm that these correlations do not result from the conductance modifying the Raman enhancement. Therefore, these observations strongly imply that multimodal sensing of individual molecules is possible in these mass-producible nanostructures.
通过单分子的电子传导受到分子电子结构以及其他极难评估的信息的影响，比如键合几何结构和化学环境。长期以来，缺乏一种独立的诊断技术一直阻碍着单分子电导研究。我们报告了用于单分子电子实验的纳米级结的电导和拉曼光谱的同时测量。对巯基苯胺和氟化低聚苯撑乙炔的拉曼响应中的闪烁和光谱扩散在时间上与电子电导的变化相关。时域有限差分计算证实，这些相关性并非由电导改变拉曼增强所致。因此，这些观察结果强烈表明，在这些可大规模生产的纳米结构中对单个分子进行多模态传感是可能的。
