title: Fabrication of a miniaturized capillary waveguide integrated fiber-optic sensor for fluoride determination.
abstract: Fluoride concentration is a key aspect of water quality and essential for human health. Too much or too little fluoride intake from water supplies is harmful to public health. In this study, a capillary waveguide integrated fiber-optic sensor was fabricated for fluoride measurement in water samples. The sensor was modularly designed with three parts, i.e., a light source, capillary flow cell and detector. When light propagated from a light emitting diode (LED) to the capillary waveguide cell through an excitation fiber, it interacted with the sensing reagent, and its intensity changed with different fluoride concentrations. Then, the light propagated to the detector through a detection fiber for absorption determination of fluoride according to Beer's law. This miniaturized sensor showed advantages of fast analysis (9.2 s) and small reagent demand (200 μL) per sample, and it also had a low detection limit (8 ppb) and high selectivity for fluoride determination. The sensor was applied to fluoride determination in different water samples. The results obtained were compared with those obtained by conventional spectrophotometry and ion chromatography, showing agreement and validating the sensor's potential application.
authors.affiliation: State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, 610500, China and School of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu, 610500, China. swpua124@126.com.
authors.forename: Yan
authors.initials: Y
authors.lastname: Xiong
authors.affiliation: School of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu, 610500, China. swpua124@126.com.
authors.forename: Chengjie
authors.initials: C
authors.lastname: Wang
authors.affiliation: School of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu, 610500, China. swpua124@126.com.
authors.forename: Tao
authors.initials: T
authors.lastname: Tao
authors.affiliation: School of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu, 610500, China. swpua124@126.com and Oil and Gas Field Applied Chemistry Key Laboratory of Sichuan Province, Southwest Petroleum University, Chengdu, 610500, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Duan
authors.affiliation: School of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu, 610500, China. swpua124@126.com.
authors.forename: Jun
authors.initials: J
authors.lastname: Tan
authors.affiliation: School of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu, 610500, China. swpua124@126.com.
authors.forename: Jiayi
authors.initials: J
authors.lastname: Wu
authors.affiliation: School of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu, 610500, China. swpua124@126.com.
authors.forename: Dong
authors.initials: D
authors.lastname: Wang