Synthesis of novel coumarin-based acid vapochromic fluorescence dye showing change of both color and fluorescence emission spectrum for application to sensitive, reusable, and washable textile sensors

Abstract

A new coumarin-based fluorescence dye, which simultaneously changes the fluorescence behavior as well as color by exposure to an acid-gas, was synthesized by modifying the dye structure so as to produce relatively long alkyl groups. The newly synthesized halochromic fluorescence dye was applied to polyethylenic fibers, such as high molecular weight polyethylene. The acid-gas sensing was functionalized not only in the solution state but also inside a matrix. A textile sensor was subsequently fabricated in this study and showed visible changes to both color and fluorescence emission properties as well as sensitivity to changes under low concentrations of gas-phase hydrogen chloride. Further, the sensing performance was sustainable and repeatable. From the washability test, it was observed that the dye did not leach out completely.