Molecular Scale Origin of Surface Plasmon Resonance Biosensors

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• 作者：Hui Yu ; Xiaonan Shan ; Shaopeng Wang ; Hongyuan Chen ; Nongjian Tao
• 刊名：Analytical Chemistry
• 出版年：2014
• 出版时间：September 16, 2014
• 年：2014
• 卷：86
• 期：18
• 页码：8992-8997
• 全文大小：338K
• ISSN：1520-6882

文摘

Surface plasmon resonance (SPR) has become an indispensable tool for label-free detection and quantification of molecular binding. Traditionally, the principle of SPR biosensors is described with a stratified medium model, in which discrete molecules are approximated with a uniform thin film. With the recent technical advances, SPR can now detect extremely low coverage of molecules, which raises the question of the validity of the traditional model. Here, we present combined theoretical, numerical and experimental analysis of SPR detection principle by considering the discrete nature of the molecules (particles). Our results show that the stratified medium model can provide reasonable description of SPR biosensors for relatively high coverage and weakly scattering samples. However, interference between the SPR images of individual particles needs to be considered for high spatial resolution images and for strong scattering samples at certain incident angles of light.