Xiao Lei, Chen Xinghong, Li Xuejin, Zhang Jinghan, Wang Yan, Li Dongqing, Hong Xueming, Shao Yonghong, Chen Yuzhi
College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China.
Shenzhen Engineering Laboratory for Optical Fiber Sensors and Networks, Shenzhen 518060, China.
Biosensors (Basel). 2025 Feb 6;15(2):90. doi: 10.3390/bios15020090.
A Mach-Zehnder interferometer-based tapered-in-tapered fiber-optic biosensor was introduced in this paper. By integrating a micro-tapered fiber into a single tapered fiber structure, the design enhances sensitivity, signal-to-noise ratio, and resolution capability, while reducing the length of the sensing fiber. Through simulation analysis, it was found that the tapered-in-tapered fiber significantly improved the refractive index detection sensitivity by exciting a stronger evanescent field effect. The experimental comparison between the tapered-in-tapered fiber and traditional tapered fiber showed a 1.7-fold increase in sensitivity, reaching 3266.78 nm/RIU within the refractive index range of 1.3326 to 1.3414. Furthermore, to expand its application prospects in the biomedical field, glutaraldehyde cross-linking technology was used to immobilize C-reactive protein (CRP) antibodies on the surface of the tapered-in-tapered fiber, successfully creating a biosensing platform for the specific recognition of CRP. The experimental results demonstrate that this novel biosensor can rapidly and accurately detect CRP molecules at different concentrations with a detection limit of 0.278 μg/mL, and that it exhibits good selectivity and repeatability. This tapered-in-tapered fiber-optic biosensor provides new insights into the development of high-performance fiber-optic immunosensors and shows broad application potential in immunology research and early disease diagnosis.
本文介绍了一种基于马赫-曾德尔干涉仪的锥中锥光纤生物传感器。通过将微锥光纤集成到单锥光纤结构中，该设计提高了灵敏度、信噪比和分辨率，同时缩短了传感光纤的长度。通过仿真分析发现，锥中锥光纤通过激发更强的倏逝场效应显著提高了折射率检测灵敏度。锥中锥光纤与传统锥光纤的实验比较表明，灵敏度提高了1.7倍，在1.3326至1.3414的折射率范围内达到3266.78 nm/RIU。此外，为了扩大其在生物医学领域的应用前景，采用戊二醛交联技术将C反应蛋白（CRP）抗体固定在锥中锥光纤表面，成功创建了一个用于特异性识别CRP的生物传感平台。实验结果表明，这种新型生物传感器能够快速、准确地检测不同浓度的CRP分子，检测限为0.278μg/mL，并且具有良好的选择性和重复性。这种锥中锥光纤生物传感器为高性能光纤免疫传感器的发展提供了新的思路，并在免疫学研究和疾病早期诊断中显示出广阔的应用潜力。
