Hollow Fiber Sensors with a Turn-On Fluorescence Response, Recycling, and Water Proofing for Monitoring Benzene Series

The wide production and application of the benzene series have led to increasingly serious air pollution in the microenvironment. Although considerable efforts have been devoted to the analysis, developing a quick, effective, and convenient monitor for such volatile organic compounds remains a remarkable challenge. Herein, we report a simple fabrication process of hollow fibers (polyimide with a pyrene group) based on wet-spinning. Due to the smooth surface of the fiber, water droplets could quickly slide off within 5 s when the fiber angle reached 40 degrees. Hydrophobicity allowed the polymer fiber to maintain a stable fluorescence performance at a relative humidity of 40 to 80%. Meanwhile, the fiber sensing material exhibited a significant fluorescence enhancement effect when the concentration of toluene reached 500 ppb. For xylene and phenethyl alcohol, the fluorescence response concentrations were both 400 ppb. It indicated that this fiber sensor is beneficial for trace detection of volatile organic compounds. Furthermore, the fiber could still be reused 6-7 times after desorption of the targets. This work provided a convenient and effective method for real-time monitoring of volatile organic compounds.