期刊
ACS NANO
卷 6, 期 11, 页码 9574-9584出版社
AMER CHEMICAL SOC
DOI: 10.1021/nn3028216
关键词
surface-enhanced Raman scattering; single-molecule detection; nanogap; core-shell particle; enhancement factor; plasmonic probe
类别
资金
- National Research Foundation of Korea (NRF)
- Korean government (MEST) [2011-0018198]
- POSCO [2011Y109]
- KRICT [KK-0904-02, SI-1110]
- Nano RD Program [2009-0082861]
- Pioneer Research Center Program of NRF [2009-0081511]
- Development of Advanced Scientific Analysis Instrumentation Project of KRISS by MEST
- Eco-technopia 21 Project by KME
- Industrial Core Technology Development Program of the Ministry of Knowledge Economy [10033183, 10037397]
- KRICT OASIS Project from the Korea Research Institute of Chemical Technology
We extensively, study the relationships between single-molecule surface-enhanced Raman scattering (SMSERS) intensity, enhancement factor (EF) distribution over many particles, Interparticle distance, particle size/shape/composition and excitation laser wavelength using the single-particle AFM-correlated Raman measurement method and theoretical calculations. Two different single-DNA-tethered Au-Ag core-shell nanodumbbell (GSND) designs with an engineerable nanogap were used In this study: the GSND-I with various interparticle nanogaps from similar to 4.8 nm to < 1 nm or with no gap and the GSND-II with the fixed interparticle gap size and varying particle size from a 23-30 nm pair to a 50-60 nm pair. From the GSND-I, we learned that synthesizing a < 1 um gap is a key to obtain strong SMSERS signals with a narrow EF value distribution. Importantly, in the case of the GSND-I with < 1 nm interparticle gap, an EF value of as high as 5.9 x 10(13) (average value = 1.8 x 10(12)) was obtained and the EF values of analyzed particles were narrowly distributed between 19 x 10(12) and 5.9 x 10(13). In the case of the GSND-II probes, a combination of > 50 nm Au cores and 514.5 nm laser wavelength that matches well with Ag shell generated stronger SMSERS signals with a more narrow EF distribution than < 50 nm Au. cores with 514.3 nm laser or the GSND-II structures with 632.8 nm laser. Our results show the usefulness and flexibility of these GSND structures In studying and obtaining SMSERS structures with a narrow distribution of high EF values and that the GSNDs with < 1 nm are promising SERS probes with highly sensitive and quantitative detection capability when optimally designed.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据