Microfluidic Raman Sensing Using a Single Ring Negative Curvature Hollow Core Fiber
Xinyu Wang,
Shuguang Li,
Shoufei Gao,
Yingying Wang,
Pu Wang,
Heike Ebendorff-Heidepriem,
Yinlan Ruan
Affiliations
Xinyu Wang
State Key Laboratory of Metastable Materials Science & Technology, Key Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao 066004, China
Shuguang Li
State Key Laboratory of Metastable Materials Science & Technology, Key Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao 066004, China
Shoufei Gao
Institute of Photonics Technology, Jinan University, Guangzhou 510632, China
Yingying Wang
Institute of Photonics Technology, Jinan University, Guangzhou 510632, China
Pu Wang
Institute of Laser Engineering, Beijing University of Technology, Beijing 100124, China
Heike Ebendorff-Heidepriem
Institute for Photonics and Advanced Sensing (IPAS), School of Physical Sciences, The University of Adelaide, Adelaide, SA 5005, Australia
Yinlan Ruan
Institute for Photonics and Advanced Sensing (IPAS), School of Physical Sciences, The University of Adelaide, Adelaide, SA 5005, Australia
A compact microfluidic Raman detection system based on a single-ring negative-curvature hollow-core fiber is presented. The system can be used for in-line qualitative and quantitative analysis of biochemicals. Both efficient light coupling and continuous liquid injection into the hollow-core fiber were achieved by creating a small gap between a solid-core fiber and the hollow-core fiber, which were fixed within a low-cost ceramic ferrule. A coupling efficiency of over 50% from free-space excitation laser to the hollow core fiber was obtained through a 350 μm-long solid-core fiber. For proof-of-concept demonstration of bioprocessing monitoring, a series of ethanol and glucose aqueous solutions at different concentrations were used. The limit of detection achieved for the ethanol solutions with our system was ~0.04 vol.% (0.32 g/L). Such an all-fiber microfluidic device is robust, provides Raman measurements with high repeatability and reusability, and is particularly suitable for the in-line monitoring of bioprocesses.
