International Research Fellowship Program: Optimization of Macroporous Metal Films as Substrates for Surfaced Enhanced Raman Spectroscopy

0601826马尔卡希国际研究奖学金计划使美国科学家和工程师能够在国外进行9到24个月的研究。 该计划的奖项提供了联合研究的机会，以及使用独特或互补的设施，专业知识和国外的实验条件。Mulcahy与Alejandro Fainstein博士在阿根廷里奥内格罗的Balserio物理研究所工作。 对该项目的支持来自国际科学与工程办公室（OISE）美洲计划。Fainstein博士的实验室是与阿根廷、新西兰和英国科学家合作的一部分，他们正在探索一种制造表面增强拉曼光谱（Sers）活性基底的新方法。 为了制造这些基底，金属在市售的亚微米尺寸的聚苯乙烯胶乳球的存在下电化学沉积，以产生大孔金属膜。 初步实验表明，它们具有更好的信号再现性，比Sers实验中使用的传统的电化学粗糙金属表面更鲁棒。 为了理解控制用新衬底观察到的增强的基本原理，在腔体内的特定区域中选择性地存款分子将是有用的。 为了实现这一目标，将生产分层金属薄膜，以提供特定金属的空腔，其中散布着一个或多个不同金属的环。 在不同的电位吸附到不同的金属表面上的烷硫醇的沉积，然后可以空间控制。 将检查纳米腔内部的活性区域以及该区域如何随腔尺寸变化。 在该技术实际用于纳米腔之前，需要验证沉积金属薄层的连续性和均匀性。 混合的金/银纳米腔对纳米腔内产生的等离子体激元的影响也将得到解决。 最后，也将探讨使用大孔膜作为Sers基底的检测极限和表面选择规则。

0601826MulcahyThe International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a fifteen-month research fellowship by Dr. Mary E. Mulcahy to work with Dr. Alejandro Fainstein at Instituto Balserio Physics in Rio Negro, Argentina. Support for this project comes from the Office of International Science and Engineering's (OISE) Americas Program. Dr. Fainstein's laboratory is part of a collaboration with scientists in Argentina, New Zealand, and the UK exploring a new method for making Surface Enhanced Raman Spectroscopy (SERS) active substrates. To make these substrates, metal is electrochemically deposited in the presence of commercially available, submicron-sized polystyrene latex spheres, to produce macroporous, metallic films. Initial experiments with the films show they exhibit better signal reproducibility and are more robust than traditional, electrochemically roughened metal surfaces used in SERS experiments. To understand the fundamental principles which govern the enhancement observed with the new substrates, it would be useful to selectively deposit molecules in specific areas within the cavities. To accomplish this, layered metal films will be produced to give cavities of a particular metal with one or more rings of a different metal interspersed in them. The deposition of alkanethiols, which adsorb onto different metal surfaces at distinct potentials, can be then be spatially controlled. The active area inside the nanocavities and how the area changes with cavity size will be examined. Continuity and uniformity of the thin layers of deposited metal will need to be verified before the technique is actually employed for the nanocavities. The effect that a mixed gold/silver nanocavity will have on the plasmon generated within the nanocavity will also be addressed. Finally, the limit of detection and surface selection rules that can be expected from using the macroporous films as SERS substrates will also be explored.