Optimization of Eu³⁺ Luminescence in DMSO as a Multiparameter Method for Trace Water Detection

Photoluminescence of Eu³⁺ in DMSO is intense and ultrasensitive to water, thereby providing a novel method for water detection. Herein, for the first time, we investigated the effects of Eu³⁺ concentration on luminescence and developed a multiparameter method for trace water detection based on a single luminescence agent. To further extend its practical applications, we explored its performance for water detection in ethanol and gasoline. Our findings demonstrate that it is a sensitive and reliable probe for the detection of a wide concentration range of water in ethanol (0–24.24%) and gasoline (0–32.43%), making Eu–DMSO a promising candidate to detect water in a wide concentration range. These phenomena not only make Eu–DMSO a sensitive agent for in situ water detection in real time but also provide scientifically interesting mechanisms behind its application as a water sensing probe.