Kim Hyo-Sop, Kim Jin-Ho, Lee SooSuk, Choi Sung-Wook, Koh Kwangnak, Kim Jae-Ho
Department of Molecular Science and Technology, Ajou University, Suwon 443-749, Korea.
J Nanosci Nanotechnol. 2009 Dec;9(12):7016-9. doi: 10.1166/jnn.2009.1623.
The Fabry-Perot fringe pattern is determined by wavelength shifts in interferometric reflectance spectroscopy, which is a function of the refractive index (n) and thickness (l) of the porous silicon (PSi). In this paper, we demonstrated the shifts of wavelength as systematic controlling of adsorbed concentration of a protein on the PSi substrate. In order to correlate the wavelength shift of the Fabry-Perot fringe pattern with the protein adsorption, adsorbed concentrations of avidin (66 kDa) on the PSi substrate were measured by three independent methods: first, by means of bromophenol blue, which is applied to surface-confined avidin; second, with fluorescence intensity measurement of FITC-tagged avidin; and finally by utilizing Time of Flight-Secondary Ion Mass Spectrometry (TOF-SIMS). It was found that the wavelength shift is directly proportional to the surface-adsorbed avidins over the wide range of surface concentration on the PSi substrate, with a rate of 0.1 nm red-shift at avidin concentration change of 1.0 fmol/cm2.
法布里 - 珀罗条纹图案由干涉反射光谱中的波长偏移决定，而干涉反射光谱是多孔硅（PSi）的折射率（n）和厚度（l）的函数。在本文中，我们展示了波长的偏移与蛋白质在PSi衬底上吸附浓度的系统控制之间的关系。为了将法布里 - 珀罗条纹图案的波长偏移与蛋白质吸附相关联，通过三种独立方法测量了抗生物素蛋白（66 kDa）在PSi衬底上的吸附浓度：第一，通过应用于表面受限抗生物素蛋白的溴酚蓝；第二，通过测量异硫氰酸荧光素标记的抗生物素蛋白的荧光强度；最后利用飞行时间二次离子质谱（TOF - SIMS）。结果发现，在PSi衬底上较宽的表面浓度范围内，波长偏移与表面吸附的抗生物素蛋白成正比，抗生物素蛋白浓度变化1.0 fmol/cm²时，波长有0.1 nm的红移。
