Zhang Han, Orosz Kristina S, Takahashi Hiromi, Saavedra S Scott
Department of Chemistry, The University of Arizona, Tucson, Arizona 85721, USA.
Appl Spectrosc. 2009 Sep;63(9):1062-7. doi: 10.1366/000370209789379295.
A commercially available spectrometer has been modified to perform plasmon waveguide resonance (PWR) spectroscopy over a broad spectral bandwidth. When compared to surface plasmon resonance (SPR), PWR has the advantage of allowing measurements in both s- and p-polarizations on a waveguide surface that is silica or glass rather than a noble metal. Here the waveguide is a BK7 glass slide coated with silver and silica layers. The resonance wavelength is sensitive to the optical thickness of the medium adjacent to the silica layer. The sensitivity of this technique is characterized and compared with broadband SPR both experimentally and theoretically. The sensitivity of spectral PWR is comparable to that of spectral SPR for samples with refractive indices close to that of water. The hydrophilic surface of the waveguide allows supported lipid bilayers to be formed spontaneously by vesicle fusion; in contrast, the surface of an SPR chip requires chemical modification to create a supported lipid membrane. Broadband PWR spectroscopy should be a useful technique to study biointerfaces, including ligand binding to transmembrane receptors and adsorption of peripheral proteins on ligand-bearing membranes.
对一种商用光谱仪进行了改进，使其能够在宽光谱带宽上进行表面等离子体波导共振（PWR）光谱分析。与表面等离子体共振（SPR）相比，PWR的优势在于可以在由二氧化硅或玻璃而非贵金属制成的波导表面上对s偏振和p偏振进行测量。此处的波导是涂有银层和二氧化硅层的BK7载玻片。共振波长对与二氧化硅层相邻的介质的光学厚度敏感。通过实验和理论方法对该技术的灵敏度进行了表征，并与宽带SPR进行了比较。对于折射率接近水的样品，光谱PWR的灵敏度与光谱SPR相当。波导的亲水性表面允许通过囊泡融合自发形成支撑脂质双层；相比之下，SPR芯片的表面需要进行化学修饰以形成支撑脂质膜。宽带PWR光谱分析应该是研究生物界面的一种有用技术，包括配体与跨膜受体的结合以及外周蛋白在含配体膜上的吸附。
