基于回音壁模式的空芯光纤光流控DNA传感器  

Hollow-Core Optical Fiber Optofluidic DNA Sensor Based on Whispering Gallery Mode

作　　者：张洪鑫 李雪刚[1] 周雪[1] 张亚男[1] 赵勇[1] Zhang Hongxin;Li Xuegang;Zhou Xue;Zhang Yanan;Zhao Yong(College of Information Science and Engineering,Northeastern University,Shenyang 110819,Liaoning,China)

机构地区：[1]东北大学信息科学与工程学院,辽宁沈阳110819

出　　处：《光学学报》2024年第9期191-199,共9页Acta Optica Sinica

基　　金：国家自然科学基金(62373088,62203090,U22A2021);广东省基础与应用研究基金(2022A1515220086);辽宁省自然科学基金(2023-MS-076);中国科协青年托举人才项目(2022QNRC001)。

摘　　要：针对原位DNA传感的测量需求,提出了一种基于空芯光纤回音壁模式(WGM)的光流控光纤传感器。从仿真和实验两个方面对提出的DNA传感器进行探究。通过仿真探究得到锥形光纤的尺寸、空芯光纤谐振腔的厚度以及锥形光纤和空芯光纤谐振腔的耦合间距对WGM的作用规律,在仿真规律的指导下设计和完成实验。实验结果表明,减小谐振腔的厚度可以提高传感器灵敏度,谐振腔厚度为2μm时的折射率灵敏度可达206 nm/RIU,是厚度为4.5μm谐振腔的灵敏度的1.4倍,满足由于DNA分子杂交而在光纤表面产生的局部折射率变化的检测灵敏度要求。通过将探针DNA固定在空芯光纤谐振腔的微流通道,可以实现互补DNA的浓度梯度检测。所提出的传感器的线性检测范围为10~100 nmol/L,灵敏度为0.56 pm/(nmol/L),线性度为0.994。此外,所提出的基于WGM的DNA光纤传感器具有很好的特异性,为原位DNA检测在医学诊断和预后中的应用提供基础。Objective The specific detection of DNA sequences plays a vital role in disease diagnosis,drug development,environmental protection,and other fields.Common DNA detection methods include electrochemical detection,semiconductor detection,and optical detection.Although the electrochemical detection method features high precision and strong practicability,it has the disadvantages of high cost and complicated detection processes.Semiconductor detection methods can detect reaction changes in real time,but the experimental operation is difficult and has strict requirements for experimental volume.Optical fiber biosensors based on the whispering gallery mode(WGM)effect have been extensively studied due to their small size,high detection accuracy,and fast response.For the measurement requirements of in-situ DNA sensing,we propose an optical fiber optofluidic sensor based on hollow-core fiber WGM.Methods The proposed sensor is prepared by coupling a tapered optical fiber and a hollow-core fiber.The sensor mainly employs the evanescent field generated by the tapered optical fiber to excite the hollow-core fiber resonant cavity to generate WGM for detection.From the perspective of the sensor composition,the diameter of the tapered fiber,the thickness of the resonant cavity,and the coupling distance between the tapered fiber and the resonant cavity will all influence the experimental detection results.Meanwhile,we explore the proposed DNA sensor from both simulation and experiment aspects.By conducting simulation analysis via Comsol software,we first obtain how the above three factors affect the experimental results.The experiment is completed under the guidance of the simulation.Additionally,we adopt the hollow-core fiber as the resonant cavity and the internal air hole of the hollow-core fiber as the microfluidic channel.In the experiment,the silanization method is utilized to immobilize probe DNA(pDNA)on the surface of the resonant cavity for subsequent detection of complementary DNA(cDNA).Results and Discussions The simul

关 键 词：医用光学 光流控光纤传感器 回音壁模式 原位DNA传感 

分 类 号：TN253[电子电信—物理电子学] TH741[机械工程—光学工程]