title: Optical fiber LPG biosensor integrated microfluidic chip for ultrasensitive glucose detection.
abstract: An optical fiber sensor integrated microfluidic chip is presented for ultrasensitive detection of glucose. A long-period grating (LPG) inscribed in a small-diameter single-mode fiber (SDSMF) is employed as an optical refractive-index (RI) sensor. With the layer-by-layer (LbL) self-assembly technique, poly (ethylenimine) (PEI) and poly (acrylic acid) (PAA) multilayer film is deposited on the SDSMF-LPG sensor for both supporting and signal enhancement, and then a glucose oxidase (GOD) layer is immobilized on the outer layer for glucose sensing. A microfluidic chip for glucose detection is fabricated after embedding the SDSMF-LPG biosensor into the microchannel of the chip. Experimental results reveal that the SDSMF-LPG biosensor based on such a hybrid sensing film can ultrasensitively detect glucose concentration as low as 1 nM. After integration into the microfluidic chip, the detection range of the sensor is extended from 2 µM to 10 µM, and the response time is remarkablely shortened from 6 minutes to 70 seconds.
authors.affiliation: Photonics Research Center, Department of Electrical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China.
authors.forename: Ming-Jie
authors.initials: MJ
authors.lastname: Yin
authors.affiliation: Photonics Research Center, Department of Electrical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China; Biosensor National Special Laboratory, College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou 310027, China.
authors.forename: Bobo
authors.initials: B
authors.lastname: Huang
authors.affiliation: Photonics Research Center, Department of Electrical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China.
authors.forename: Shaorui
authors.initials: S
authors.lastname: Gao
authors.affiliation: Photonics Research Center, Department of Electrical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China.
authors.forename: A Ping
authors.initials: AP
authors.lastname: Zhang
authors.affiliation: Biosensor National Special Laboratory, College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou 310027, China.
authors.forename: Xuesong
authors.initials: X
authors.lastname: Ye
keywords: (050.2770) Gratings; (060.2370) Fiber optics sensors; (160.1435) Biomaterials; (280.1415) Biological sensing and sensors