KU Leuven, Department of Biosystems - Biosensors Group, Willem de Croylaan 42, Box 2428, Leuven 3001, Belgium.
ACS Sens. 2021 Oct 22;6(10):3677-3684. doi: 10.1021/acssensors.1c01447. Epub 2021 Oct 11.
Fiber optic surface plasmon resonance (FO-SPR)-based biosensors have emerged as powerful tools for biomarker detection due to their ability for real-time analysis of biomolecular interactions, cost-effectiveness, and user-friendliness. However, as (FO-)SPR signals are determined by the mass of the target molecules, the detection of low-molecular-weight targets remains challenging and currently requires tedious labeling and preparation steps. Therefore, in this work, we established a new concept for low-molecular-weight target detection by implementing duplexed aptamers on an FO-SPR sensor. In this manner, we enabled one-step competitive detection and could achieve significant signals, independent of the weight of the target molecules, without requiring labeling or preprocessing steps. This was demonstrated for the detection of a small molecule (ATP), protein (thrombin), and ssDNA target, thereby reaching detection limits of 72 μM, 36 nM, and 30 nM respectively and proving the generalizability of the proposed bioassay. Furthermore, target detection was successfully achieved in 10-fold diluted plasma, which demonstrated the applicability of the assay in biologically relevant matrices. Altogether, the developed one-step competitive FO-SPR bioassay opens up possibilities for the detection of low-molecular-weight targets in a fast and straightforward manner.
基于光纤表面等离子体共振（FO-SPR）的生物传感器因其能够实时分析生物分子相互作用、具有成本效益和用户友好性，已成为生物标志物检测的有力工具。然而，由于（FO-）SPR 信号取决于目标分子的质量，因此对低分子量目标的检测仍然具有挑战性，目前需要繁琐的标记和准备步骤。因此，在这项工作中，我们通过在 FO-SPR 传感器上实施双串联适体，建立了一种用于低分子量目标检测的新概念。通过这种方式，我们能够实现一步式竞争检测，并获得显著的信号，而与目标分子的重量无关，无需进行标记或预处理步骤。这在小分子（ATP）、蛋白质（凝血酶）和 ssDNA 目标的检测中得到了证明，分别达到了 72 μM、36 nM 和 30 nM 的检测限，并证明了所提出的生物测定法的通用性。此外，在 10 倍稀释的血浆中成功实现了目标检测，证明了该测定法在生物相关基质中的适用性。总之，开发的一步竞争 FO-SPR 生物测定法为快速、直接地检测低分子量目标提供了可能性。
