Directional Nanoplasmonic Antennas for Self-Referenced Refractometric Molecular Analysis

详细信息    查看全文

• 作者：Martin Wers盲ll ; Ruggero Verre ; Mikael Svedendahl ; Peter Johansson ; Mikael K盲ll ; Timur Shegai
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：September 11, 2014
• 年：2014
• 卷：118
• 期：36
• 页码：21075-21080
• 全文大小：319K
• ISSN：1932-7455

文摘

Localized surface-plasmon resonance (LSPR) sensors are typically based on tracing resonance peak shifts that precisely follow changes in the local refractive index. Such measurements usually require a spectrometer, a stable light source, and an accurate LSPR position tracing technique. As a simple but efficient alternative, we investigated a self-referenced single-wavelength sensing scheme based on angle-dependent and highly directional radiation patterns originating from a monolayer of asymmetric gold nanodimers. We found that one could easily trace a model biotin鈥搉eutravidin recognition reaction as well as minute bulk refractive index changes, by measuring the intensity ratio between the light scattered in two different directions with respect to the dimers. The refractometric resolution of the methodology was estimated to be on the order of 螖n 鈮?10^鈥? RIU. These results may be particularly useful for label-free biosensing applications that require a combination of simple and cost-effective optical readout with a reasonable sensitivity.