Chemically patterned microspheres for controlled nanoparticle assembly in the construction of SERS hot spots
Chemically patterned microspheres for controlled nanoparticle assembly in the construction of SERS hot spots
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DOI：
10.1021/ja072533e
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发表时间：
2007-06-27
影响因子：
15
通讯作者：
Moskovits, Martin
中科院分区：
文献类型：
--
作者：
Braun, Gary;Pavel, Ioana;Moskovits, Martin
开发超灵敏表面增强拉曼光谱（SERS）平台的一个重要挑战在于创建纳米级热点，即电磁场高度集中的位置。即使这是成功的，找到这些热点也是一项艰巨的任务。我们描述了一种新的化学微球图图化技术，利用硅化过程中的接触掩蔽优先结合银纳米颗粒到几何限制的位置。小的双功能连接剂（即< 2nm）用于将不同微球上的银颗粒结合在一起，从而形成小的纳米颗粒聚集体，其中包含一个或多个热点，其尺寸与连接剂在连接处的尺寸相同。微球限制了纳米颗粒聚集的程度，并且足够大，可以通过光学显微镜看到，在大多数情况下直接导致热点的位置，从而产生最强烈的SERS信号。
An important challenge in developing ultra-sensitive surface enhanced Raman spectroscopy (SERS) platforms lies in the creation of nanoscale hot spots, locations where the electromagnetic field is greatly concentrated. Even when this is successful, finding these hot spots is a difficult task. We describe a novel chemical microsphere patterning technique utilizing contact masking during silanization for bonding silver nanoparticles preferentially to geometrically restricted sites. Small bifunctional linkers (i.e., < 2 nm) are used to bind silver particles on different microspheres drawing the two together, thereby forming small nanoparticle aggregates containing one or more hot spots with the dimensions of the linker at the junction. The microspheres limit the extent of nanoparticle aggregation and are large enough to be visible by optical microscopy leading in most cases directly to the location of the hot spots and hence the most intense SERS signals.