Surface characterization and efficiency of a matrix-free and flat carboxylated gold sensor chip for surface plasmon resonance (SPR)

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• 作者：L. Roussille (1)
  G. Brotons (1) guillaume.brotons@univ-lemans.fr
  L. Ballut (2)
  G. Louarn (3)
  D. Ausserr茅 (1)
  S. Ricard-Blum (2)
• 关键词：Self ; assembled monolayer &#8211 ; gold surface &#8211 ; surface characterization &#8211 ; biosensor &#8211 ; protein&#8211 ; protein interaction &#8211 ; surface plasmon resonance
• 刊名：Analytical and Bioanalytical Chemistry
• 出版时间：September 2011
• 出版年：2011
• 期刊代码：8_1618-2642
• 类别：en
• 卷：401
• 期：5
• 页码：1605-1621
• 数据来源：sp

摘要

We report the preparation and characterization of a matrix-free carboxylated surface plasmon resonance (SPR) sensor chip with high sensing efficiency by functionalizing a bare gold thin film with a self-assembled monolayer of 16-mercaptohexadecanoic acid (SAM–MHDA chip). The self assembled monolayer surface coverage of the gold layer was carefully evaluated and the SAM was characterized by infrared reflection absorption spectroscopy, X-ray photoemission spectroscopy, atomic force microscopy, X-ray reflectivity-diffraction, and SPR experiments with bovine serum albumin. We compared the SPR signal obtained on this chip made of a dense monolayer of carboxylic acid groups with commercially available carboxylated sensor chips built on the same gold substrate, a matrix-free C1 chip, and a CM5 chip with a ~100 nm dextran hydrogel matrix (GE Healthcare). Two well-studied interaction types were tested, the binding of a biotinylated antibody (immunoglobulin G) to streptavidin and an antigen–antibody interaction. For both interactions, the well characterized densely functionalized SAM–MHDA chip gave a high signal-to-noise ratio and showed a gain in the availability of immobilized ligands for their partners injected in buffer flow. It thus compared favourably with commercially available sensor chips.