Rong Guoguang, Najmaie Ali, Sipe John E, Weiss Sharon M
Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, TN 37212, USA.
Biosens Bioelectron. 2008 May 15;23(10):1572-6. doi: 10.1016/j.bios.2008.01.017. Epub 2008 Jan 24.
Porous silicon (PSi) is an excellent material for biosensing due to its large surface area and its capability for molecular size selectivity. In this work, we report the experimental demonstration of a label-free nanoscale PSi resonant waveguide biosensor. The PSi waveguide consists of pores with an average diameter of 20nm. DNA is attached inside the pores using standard amino-silane and glutaraldehyde chemistry. Molecular binding in the PSi is detected optically based on a shift of the waveguide resonance angle. The magnitude of the resonance shift is directly related to the quantity of biomolecules attached to the pore walls. The PSi waveguide sensor can selectively discriminate between complementary and non-complementary DNA. The advantages of the PSi waveguide biosensor include strong field confinement and a sharp resonance feature, which allow for high sensitivity measurements with a low detection limit. Simulations indicate that the sensor has a detection limit of 50nM DNA concentration or equivalently, 5pg/mm2.
多孔硅（PSi）因其大表面积和分子尺寸选择性能力，是一种用于生物传感的优异材料。在这项工作中，我们报告了一种无标记纳米级PSi共振波导生物传感器的实验演示。PSi波导由平均直径为20nm的孔组成。使用标准的氨基硅烷和戊二醛化学方法将DNA附着在孔内。基于波导共振角的偏移，通过光学方法检测PSi中的分子结合。共振偏移的幅度与附着在孔壁上的生物分子数量直接相关。PSi波导传感器可以选择性地区分互补和非互补DNA。PSi波导生物传感器的优点包括强场限制和尖锐的共振特征，这使得能够以低检测限进行高灵敏度测量。模拟表明，该传感器的检测限为50nM DNA浓度，或等效地为5pg/mm²。
