Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106-9510, United States.
Nano Lett. 2010 Oct 13;10(10):4181-5. doi: 10.1021/nl102495j.
A bifunctional adenosine-sensitive double-stranded DNA aptamer was used to create and control a surface-enhanced Raman spectroscopy (SERS) hot spot between a bulk Au surface and a gold nanoparticle (Au NP) attached to the aptamer via a biotin-avidin linkage. The Au NP was decorated with 4-aminobenzenethiol (4-ABT), a Raman reporter molecule. In the presence of adenosine, the target molecule, the SERS spectrum of 4-ABT increased in intensity by (concentration-dependent) factors as large as ∼4; in situ, atomic force microscopy imaging showed the mean height of the Au NP-bearing aptamer to decrease by ∼5 nm consistent with the observed SERS intensity change. Because the aptamer's geometrical change is induced by one or two molecules, while the resulting SERS intensity changes involve many reporter molecules residing in the modified hot spot, the aptamer amplifies the SERS effect.
一种双功能的腺苷敏感双链 DNA 适体被用于在大块 Au 表面和通过生物素-亲和素键连接到适体的金纳米粒子（AuNP）之间创建和控制表面增强拉曼光谱（SERS）热点。AuNP 被 4-氨基苯硫醇（4-ABT）修饰，这是一种拉曼报告分子。在存在腺苷（靶分子）的情况下，4-ABT 的 SERS 谱强度增加了（浓度依赖性）高达约 4 倍；原位原子力显微镜成像显示，带有 AuNP 的适体的平均高度降低了约 5nm，与观察到的 SERS 强度变化一致。由于适体的几何变化是由一个或两个分子诱导的，而产生的 SERS 强度变化涉及许多驻留在修饰热点中的报告分子，因此适体放大了 SERS 效应。
