Biosensing using porous silicon double-layer interferometers: Reflective interferometric Fourier transform spectroscopy
Biosensing using porous silicon double-layer interferometers: Reflective interferometric Fourier transform spectroscopy
复制标题
DOI：
10.1021/ja0511671
复制
发表时间：
2005-08-24
影响因子：
15
通讯作者：
Miskelly, GM
中科院分区：
文献类型：
--
作者：
Pacholski, C;Sartor, M;Miskelly, GM
介绍了一种简单的基于芯片的双光束干涉仪的实现，该干涉仪可以根据大小分离生物分子，并且可以补偿基质组成的变化。该干涉式生物传感器采用双层多孔硅，由大孔的顶层和小孔的底层组成。该结构提供了类似于双光束光谱仪的片上参考通道，但是参考室和样品室被一个堆叠在另一个之上。这种结构的反射率光谱显示出复杂的干涉图案，其各个分量可以通过将反射率数据拟合到简单的干涉模型或通过快速傅立叶变换(FFT)来解析。FFT峰的移动表明生物分子穿透到不同的层中。小分子蔗糖穿透到两个多孔硅层，而大蛋白质牛血清白蛋白(BSA)只进入大孔。即使从FFT光谱中检测到大量(100倍质量的)过量蔗糖，也能检测到牛血清白蛋白。检测可以通过计算两个峰的频率的加权差或通过计算FFT谱中两个峰的强度之比来完成。
A simple, chip-based implementation of a double-beam interferometer that can separate biomolecules based on size and that can compensate for changes in matrix composition is introduced. The interferometric biosensor uses a double-layer of porous Si comprised of a top layer with large pores and a bottom layer with smaller pores. The structure is shown to provide an on-chip reference channel analogous to a double-beam spectrometer, but where the reference and sample compartments are stacked one on top of the other. The reflectivity spectrum of this structure displays a complicated interference pattern whose individual components can be resolved by fitting of the reflectivity data to a simple interference model or by fast Fourier transform (FFT). Shifts of the FFT peaks indicate biomolecule penetration into the different layers. The small molecule, sucrose, penetrates into both porous Si layers, whereas the large protein, bovine serum albumin (BSA), only enters the large pores. BSA can be detected even in a large (100-fold by mass) excess of sucrose from the FFT spectrum. Detection can be accomplished either by computing the weighted difference in the frequencies of two peaks or by computing the ratio of the intensities of two peaks in the FFT spectrum.