A multifunctional fluorescence sensor for DNT vapor and Fe3+ based on a conjugated polymer

Due to the molecular wire effect, the fluorescent conjugated polymer (FCP) is always one of the focus of the sensor field. However, the complicated synthesis of FCP usually hinders their further practical application. Meanwhile, the multifunctional fluorescence sensor, which can distinguish multi-analyte only by one sensing material, presents high potential prospect in the real application. Here, a relatively simple benzimidazole-based FCP P1 via Suzuki polymerization was synthesized and further used as a multifunctional fluorescence sensor: P1 can not only efficiently detect Fe³⁺ in solution with a limit of detection (LOD) of 60 nM, but also monitor 2, 4-dinitrotoluene (DNT) vapor with a low LOD of 3.3 ppb. Furthermore, the simple P1 filter paper sensor was prepared and enable visual detection of Fe³⁺ and DNT with high performances of portability, flexibility and practicability.