Fluorescent alumina fibers: A fluorescent sensor for detecting trace amounts of water in organic solvents

Water is a typical impurity in organic solvents, and the detection of trace amounts of water in organic solvents is of great significance both in the chemical field and industrial applications. This work described an innovative preparation method of rare earth europium (Eu³⁺) complexes being grafted on the surface of alumina fibers, which successfully prepared fluorescent alumina fibers and were used as fluorescent probes to detect water in organic solvents. The alumina fibers were prepared by electrostatic spinning, then the surface of alumina was modified by silane coupling agent (APTES) with maleic anhydride (MAH), and finally rare earth europium complexes was grafted on the surface of alumina fibers. The results showed that the rare earth complexes successfully grew on the alumina surface and bonded with –OH on the alumina surface. The addition of water resulted in an overall quenching of the fluorescence intensity of the fluorescent alumina fibers, with detection limits of 0.079 % v/v, 0.121 % v/v, and 0.062 % v/v in ethanol, DMF, and acetone solutions, respectively. This paper provides an innovative approach and methodology for the study of water content detection in organic solvents. This research broadens the potential applications of alumina fibers in functionalization.