Surface Plasmon Enhanced Diffraction for Label-Free Biosensing

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• 作者：Fang Yu ; Shengjun Tian ; Danfeng Yao ; and Wolfgang Knoll
• 刊名：Analytical Chemistry
• 出版年：2004
• 出版时间：July 1, 2004
• 年：2004
• 卷：76
• 期：13
• 页码：3530 - 3535
• 全文大小：167K
• 年卷期：v.76,no.13(July 1, 2004)
• ISSN：1520-6882

文摘

Surface plasmon enhanced evanescent field at a (noble)metal/dielectric interface can be employed to enhance thediffraction efficiency of surface grating structure composed of biomolecules. Based on a Kretschmann configuration, we realized a diffraction biosensor to monitor thedynamic interaction of biological molecules in a label-freeway. It was demonstrated by the binding of an anti-biotinantibody to the biotin-functionalized region of a periodically patterned surface, which generated significant opticalcontrast to diffract the surface plasmon field. With the aidof the synchronic surface plasmon resonance signal, aquadratic dependence of diffraction signal on the amountof bound antibody was found, which coincides with thetheoretical expectation. Time-dependent measurementswere conducted to estimate the density of biotin thiols onthe functional region.