A turn-on fluorescence probe based on post-modified metal–organic frameworks for highly selective and fast-response hypochlorite detection

Abstract

Hypochlorite/hypochlorous acid has been commonly regarded as one of the most vital reactive oxygen species in various physiological and pathological processes. However, the highly efficient detection of OCl− still remains a challenging work. Here, we fabricated a fluorescent MOF-based OCl− probe (ZIF-90-BA) by post-functionally modifying ZIF-90 with the Schiff base group. ZIF-90-BA features water stability, porous structures and functional sites. This probe was successfully used for OCl− turn-on fluorescence sensing. The Schiff base group on the ZIF-90-BA could be oxidized by OCl− and the flexible alkyl chain would put off, resulting in the turn-on fluorescence behavior. ZIF-90-BA exhibited high selectivity over other potentially interfering species, and it showed high sensitivity (detection limit: 6.25 μM) and fast response (15 s). It is anticipated that ZIF-90-BA can be a promising material for OCl− fluorescence sensing.