Optical Bio-Microsystems Laboratory, Department of Mechanical and Industrial Engineering, Concordia University, Montreal, Canada.
J Biophotonics. 2013 May;6(5):457-67. doi: 10.1002/jbio.201200094. Epub 2012 Jul 24.
An evanescent wave based biosensor is developed on the silica-on-silicon (SOS) with a cascaded waveguide coupler for the detection of recombinant growth hormone. So far, U -bends and tapered waveguides are demonstrated for increasing the penetration depth and enhancing sensitivity of the evanescent wave sensor. In this work, a monolithically integrated sensor platform containing a cascaded waveguide coupler with optical power splitters and combiners designed with S -bends and tapper waveguides is demonstrated for an enhanced detection of recombinant growth hormone. In the cascaded waveguide coupler, a large surface area to bind the antibody with increased penetration depth of evanescent wave to excite the tagged-rbST is obtained by splitting the waveguide into multiple paths using Y splitters designed with s -bends and subsequently combining them back to a single waveguide through tapered waveguide and combiners. Hence a highly sensitive fluoroimmunoassay sensor is realized. Using the 2D FDTD (Finite-difference time-domain method) simulation of waveguide with a point source in Rsoft FullWAVE, the fluorescence coupling efficiency of straight and bend section of waveguide is analyzed. The sensor is demonstrated for the detection of fluorescently-tagged recombinant growth hormone with the detection limit as low as 25 ng/ml.
基于消逝波的生物传感器是在硅上硅（SOS）上开发的，采用级联波导耦合器用于检测重组生长激素。到目前为止，已经证明 U 型弯和锥形波导可以增加消逝波光传感器的穿透深度并提高其灵敏度。在这项工作中，演示了一种单片集成的传感器平台，该平台包含一个级联波导耦合器，其中设计了带有 S 型弯和锥形波导的光功率分束器和组合器，用于增强对重组生长激素的检测。在级联波导耦合器中，通过使用 Y 分束器将波导分成多个路径（设计带有 S 型弯），并通过锥形波导和组合器将它们重新组合到单个波导中，从而获得了更大的表面积来结合抗体，并增加了消逝波光的穿透深度，以激发标记的 rbST。因此，实现了高灵敏度的荧光免疫分析传感器。使用 Rsoft FullWAVE 中的二维 FDTD（有限差分时域方法）模拟具有点源的波导，分析了波导直段和弯段的荧光耦合效率。该传感器用于检测荧光标记的重组生长激素，检测限低至 25ng/ml。
