The "off-on" fluorescent probe based on salicylic acid for rapid and selective detection of 1-hydroxyethane-1,1-diphosphonic acid.

[Display omitted] • Designed a fluorescent probe to detect 1-hydroxyethane-1,1-diphosphonic acid. • Explored the optimum conditions for detection. • Researched the fluorescence quenching mechanism in detail. Organic phosphonates are widely used as scale inhibitors and metal ion chelators in industrial water treatment. 1-hydroxyethane-1,1-diphosphonic acid (HEDP) is one of the application of extensive organic phosphonates. However, due to physical and chemical properties, the detection process is extremely complicated. In this work, a fluorescent probe was prepared to detect HEDP which used salicylic acid (SA) and ferric ion (Fe3+) as sources for the first time. As far as optical properties were concerned, Fe3+-salicylic acid complex (Fe-SA) designed as fluorescent probe was significantly different from SA. The detection limit of HEDP was 2.7 μM (0.56 mg/L) under the optimal experimental conditions. The fluorescence quenching of SA can be attributed to static quenching.. [ABSTRACT FROM AUTHOR]