Key Laboratory of Optical Fiber Sensing and Communications (Ministry of Education of China), School of Information and Communication Engineering, University of Electronic Science and Technology of China, No. 2006, Xiyuan Ave., Chengdu, 611731 China.
School of Electrical and Electronics Engineering, Nanyang Technological University, 50 Nanyang Ave, Singapore, 639798 Singapore.
Lab Chip. 2021 May 4;21(9):1686-1693. doi: 10.1039/d0lc01332c.
Microstructures can improve both sensitivity and assay time in heterogeneous assays (such as ELISA) for biochemical analysis; however, it remains a challenge to perform the essential wash process in those microstructure-based heterogeneous assays. Here, we propose a sequential bioconjugation protocol to solve this problem and demonstrate a new type of fiber optofluidic laser for biosensing. Except for acting as an optical microresonator and a microstructured substrate, the miniaturized hollow optical fiber (HOF) is used as a microfluidic channel for storing and transferring reagents thanks to its capability in length extension. Through the capillary action, different reagents were sequentially withdrawn into the fiber for specific binding and washing purposes. By using the sequentially bioconjugated FOFL, avidin molecules are detected based on competitive binding with a limit of detection of 9.5 pM, ranging from 10 pM to 100 nM. It is demonstrated that a short incubation time of 10 min is good enough to allow the biomolecules to conjugate on the inner surface of the HOF. Owing to its miniaturized size, only 589 nL of liquid is required for incubation, which reduces the sample consumption and cost for each test. This work provides a tool to exploit the potential of microstructured optical fibers in high-performance biosensing.
微结构可以提高生化分析中异质分析（如 ELISA）的灵敏度和分析时间；然而，在基于微结构的异质分析中进行必要的洗涤过程仍然是一个挑战。在这里，我们提出了一种顺序生物共轭方案来解决这个问题，并展示了一种用于生物传感的新型光纤光流体激光。除了作为光学微谐振器和微结构基底外，由于其长度可扩展的特性，小型化空心光纤（HOF）还可用作微流道来储存和传输试剂。通过毛细作用，不同的试剂被顺序地吸入纤维中进行特定的结合和洗涤目的。通过使用顺序生物共轭的 FOFL，可以基于与检测限为 9.5 pM（从 10 pM 到 100 nM）的竞争结合来检测亲和素分子。结果表明，10 分钟的短孵育时间足以允许生物分子在 HOF 的内表面上进行共轭。由于其小型化尺寸，仅需 589 nL 的液体用于孵育，从而减少了每个测试的样品消耗和成本。这项工作为利用微结构光纤在高性能生物传感中的潜力提供了一种工具。
