Electromagnetism and Telecommunications Department, University of Mons, Mons, Belgium.
Biosens Bioelectron. 2014 Jan 15;51:249-54. doi: 10.1016/j.bios.2013.07.030. Epub 2013 Jul 19.
Surface Plasmon resonance (SPR) optical fiber biosensors constitute a miniaturized counterpart to the bulky prism configuration and offer remote operation in very small volumes of analyte. They are a cost-effective and relatively straightforward technique to yield in situ (or even possibly in vivo) molecular detection. The biosensor configuration reported in this work uses nanometric-scale gold-coated tilted fiber Bragg gratings (TFBGs) interrogated by light polarized radially to the optical fiber outer surface, so as to maximize the optical coupling with the SPR. These gratings were recently associated to aptamers to assess their label-free biorecognition capability in buffer and serum solutions. In this work, using the well-acknowledged biotin-streptavidin pair as a benchmark, we go forward in the demonstration of their unique sensitivity. In addition to the monitoring of the self-assembled monolayer (SAM) in real time, we report an unprecedented limit of detection (LOD) as low as 2 pM. Finally, an immunosensing experiment is realized with human transferrin (dissociation constant Kd~10(-8) M(-1)). It allows to assess both the reversibility and the robustness of the SPR-TFBG biosensors and to confirm their high sensitivity.
表面等离子体共振（SPR）光纤生物传感器是一种对庞大棱镜配置的小型化对应物，可在非常小的分析物体积中进行远程操作。它们是一种具有成本效益且相对简单的技术，可以实现原位（甚至可能是体内）分子检测。本工作中报告的生物传感器配置使用纳米级金涂覆的倾斜光纤布拉格光栅（TFBG），通过径向偏振光对其进行检测，以最大限度地提高与 SPR 的光学耦合。这些光栅最近与适体相关联，以评估它们在缓冲液和血清溶液中的无标记生物识别能力。在这项工作中，我们使用众所周知的生物素-链霉亲和素对作为基准，进一步展示了它们独特的灵敏度。除了实时监测自组装单层（SAM）外，我们还报告了前所未有的低检测限（LOD）低至 2 pM。最后，进行了人转铁蛋白的免疫传感实验（解离常数 Kd~10(-8) M(-1)）。它可以评估 SPR-TFBG 生物传感器的可逆性和鲁棒性，并确认其高灵敏度。
