AIT Austrian Institute of Technology GmbH, Health & Environment, Nano Systems, Donau-City-Strasse 1, 1220 Vienna, Austria.
Department of Analytical Chemistry, University of Vienna, Waehringer Strasse 38, 1090 Vienna, Austria.
Biosens Bioelectron. 2011 May 15;26(9):3832-7. doi: 10.1016/j.bios.2011.02.042. Epub 2011 Mar 3.
We report the development of a Mach-Zehnder interferometer biosensor based on a high index contrast polymer material system and the demonstration of label-free online measurement of biotin-streptavidin binding on the sensor surface. The surface of the polyimide waveguide core layer was functionalized with 3-mercaptopropyl trimethoxy silane and malemide tagged biotin. Several concentrations of Chromeon 642-streptavidin dissolved in phosphate buffered saline solution were rinsed over the functionalized sensor surface by means of a fluidic system and the biotin-streptavidin binding process was observed in the output signal of the interferometer at a wavelength of 1310 nm. Despite the large wavelength and the comparatively low surface sensitivity of the sensor system due to the low index contrast in polymer material systems compared to inorganic material systems, we were able to resolve streptavidin concentrations of down to 0.1 μg/ml. The polymer-based optical sensor design is fully compatible with cost-efficient mass production technologies such as injection molding and spin coating, which makes it an attractive alternative to inorganic optical sensors.
我们报告了一种基于高折射率对比聚合物材料系统的马赫-曾德尔干涉仪生物传感器的开发，并展示了在传感器表面上对生物素-链霉亲和素结合进行无标记在线测量的实例。聚酰亚胺波导芯层的表面用 3-巯丙基三甲氧基硅烷和马来酰亚胺标记的生物素进行功能化。通过流体系统将几种浓度的溶解在磷酸盐缓冲盐溶液中的 Chromon 642-链霉亲和素冲洗到功能化的传感器表面上，并在 1310nm 的波长处观察干涉仪的输出信号中的生物素-链霉亲和素结合过程。尽管由于聚合物材料系统与无机材料系统相比折射率对比低，传感器系统的波长较大且表面灵敏度相对较低，但我们仍能够分辨出低至 0.1μg/ml 的链霉亲和素浓度。基于聚合物的光学传感器设计与低成本、高效率的大规模生产技术（如注塑和旋涂）完全兼容，这使其成为无机光学传感器的有吸引力的替代方案。
