SERS substrates fabricated with star-like gold nanoparticles for zeptomole detection of analytes
SERS substrates fabricated with star-like gold nanoparticles for zeptomole detection of analytes
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DOI：
10.1039/c5nr02004b
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发表时间：
2015-01-01
期刊：
影响因子：
6.7
通讯作者：
De la Rosa, Elder
中科院分区：
文献类型：
--
作者：
Perez-Mayen, Leonardo;Oliva, Jorge;De la Rosa, Elder
本文介绍了利用星形金纳米颗粒设计表面增强拉曼散射（SERS）衬底的方法，该纳米颗粒是用湿化学方法合成的，并被1-十二烷基硫醇功能化。该分子使我们在金星之间获得了类似2.6 nm的间距，促进了单分子检测SERS热点的产生。采用Langmuir-Blodgett方法将金纳米颗粒沉积在硅衬底或涂有金的硅衬底上，该方法允许zeptomole检测罗丹明B（每激光光斑面积的总摩尔数）。这种检测水平的拉曼增强因子（EF）为10(12)，并且是在Si/Au膜/Au纳米颗粒结构的SERS衬底上获得的。同时测定了TWEEN 20和对terphenyl分子的拉曼光谱，以阐明分子长度对增强因子的影响。根据这些结果，我们的无金膜SERS底物可用于类似于10（-14）摩尔大小等于或小于1.3 nm的分析物和类似于10（-18）摩尔有金膜的分析物的最低检测水平（每个样品的总摩尔数）。
This work presents the design of substrates for Surface Enhanced Raman Scattering (SERS) using star-like gold nanoparticles which were synthesized using a wet chemical method and functionalized with 1-dodecanethiol. This molecule allowed us to obtain a spacing of similar to 2.6 nm among gold stars, which promoted the generation of SERS hotspots for single molecule detection. The gold nanoparticles were deposited on silicon substrates or on gold coated silicon substrates by using the Langmuir-Blodgett method which permitted the zeptomole detection of Rhodamine B (total moles per laser spot area). The Raman enhancement factor (EF) achieved for this level of detection was 10(12), and was obtained on the SERS substrate fabricated with the configuration: Si/Au film/Au nanoparticles. Raman spectra of the molecules TWEEN 20 and p-terphenyl were also measured in order to elucidate the effect of the molecule's length on the enhancement factor. According to these results, our SERS substrates without the gold film are useful for a minimum detection level of similar to 10(-14) moles of analytes with sizes equal to or less than 1.3 nm and similar to 10(-18) moles of analytes with the gold film (total moles per sample).