Plasmonic Nanorice Antenna on Triangle Nanoarray for Surface-Enhanced Raman Scattering Detection of Hepatitis B Virus DNA
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- 作者：Ming Li ; Scott K. Cushing ; Hongyan Liang ; Savan Suri ; Dongling Ma ; Nianqiang Wu
- 刊名：Analytical Chemistry
- 出版年：2013
- 出版时间：February 19, 2013
- 年：2013
- 卷：85
- 期：4
- 页码：2072-2078
- 全文大小：365K
- 年卷期：v.85,no.4(February 19, 2013)
- ISSN：1520-6882
文摘
The sensitivity and the limit of detection of Raman sensors are limited by the extremely small scattering cross section of Raman labels. Silver nanorice antennae are coupled with a patterned gold triangle nanoarray chip to create spatially broadened plasmonic 鈥渉ot spots鈥? which enables a large density of Raman labels to experience strong local electromagnetic field. Finite difference time domain simulations have confirmed that the quasi-periodic structure increases the intensity and the area of the surface plasmon resonance (SPR), which enhances the surface-enhanced Raman scattering (SERS) signal significantly. The SERS signal of the nanorice/DNA/nanoarray chip is compared with that of the nanorice/DNA/film chip. The SERS signal is greatly enhanced when the Ag nanorices are coupled to the periodic Au nanoarray instead of the planar film chip. The resulting spatially broadened SPR field enables the SERS biosensor with a limit of detection of 50 aM toward hepatitis B virus DNA with the capability of discriminating a single-base mutant of DNA. This sensing platform can be extended to detect other chemical species and biomolecules such as proteins and small molecules.