Acriflavine-modified UIO-66 ratiometric fluorescent sensor for highly selective and fast detection of hypochlorite in water.

Hypochlorite (ClO) as a kind of highly toxic pollutant has garnered significant interest in detection methods, highlighting the pressing need to develop intelligent functional materials for the qualitative and quantitative analysis of ClO in aqueous solutions. Herein, a ratiometric fluorescent sensor was prepared by the combination of acriflavine (Acr) and UIO-66 via a post-synthetic modification strategy. Acr/UIO-66 exhibited both high crystallinity typical of metal-organic frameworks and demonstrated good fluorescent and thermal stability. Additionally, Acr/UIO-66 functioned effectively as a dual-responsive fluorescent platform for detecting ClO in domestic drinking and surface water samples. This material displayed high sensitivity, exceptional selectivity, and superior anti-interference capabilities, along with fast respond time (60 s), a wide pH range (4.0-7.0), high recoveries (94.46-118.00 %), a broad linear range (0-28 µmol L) and low detection limits (0.74 µmol L). This study broadened the potential applications of fluorescent metal-organic frameworks and presented a feasible solution for water quality monitoring.