Preparation of a versatile fluorescence sensor for co-detecting ions in aqueous solution

A multifunctional fluorescence sensor is an important analytical method for detecting water quality. Herein, PCBH-FS, a fluorescence sensor, is first constructed by dispersing a new compound PCBH in THF-H 2 O (fw 60%, v/v). PCBH-FS exhibits a distinct red-shifted emission from 405 to 475 nm and a “turn-on” fluorescence response to Fe 3+ and Al 3+ in the pH range of 5–9, and PCBH-FS exhibits a good fluorescence response to H + in the pH range from 1 to 5. The Al 3+ -PCBH system can be used for F − detection, while the Al 3+ -PCBH and Fe 3+ -PCBH systems can be used for sequential AcO − detection in THF/H 2 O mixed media. The binding ratio and the possible sensing mechanism between cations and PCBH molecules are discussed clearly. The LOD of the PCBH-FS reaches 0.44 µM, 0.36 µM, 2.02 µM, and 1.45 µM for detecting Fe 3+ , Al 3+ , F − , and AcO − in turn. The sensor provides a simple “on-off” & fluorescent-shift co-detection strategy for sequential detection of multiple ions in aqueous solutions.