Sensor with Strong Solid Emission for Fluorescence Colormetric Detection of 1, 4-Dioxane in Water and Vapor Based on the Keto-Enol Isomerisation.

In this work, an easy prepared solid fluorescent sensor 3-(benzo[d]thiazol-2-yl)-1-hydroxy-4-oxo-3,4-dihydrophthalazine-6-carboxylic acid (BPCA) was designed and synthesized and the structure was proved by IR, UV-Vis, NMR, HRMS and elemental analysis, which displayed high selectivity and sensitivity for fluorescence colormetric from green to blue sensing 1, 4-dioxane in water, and the detection limit was obtained 0.009% and the stability constant was 7.4 × 10 M. Also, sensor BPCA was applied for the real-time monitoring 1, 4-dioxane vapor with apparent fluorescent color change from green to blue. The mild and specific chemical interaction between sensor BPCA and 1, 4-dioxane molecule allowed the sensor as portable chips to respond 1, 4-dioxane vapor with good selectivity over other common VOCs at room temperature. Also, the sensing mechanism based on the 1, 4-dioxane-induced keto-enol tautomerization of the phthalazine moiety was found and supported by DFT calculations. This sensor could serve as the basis of gas analyzers for detecting 1, 4-dioxane in the environment.