Luminescent metal organic frameworks with recognition sites for detection of hypochlorite through energy transfer

A luminescent metal organic framework (LMOF) of type UiO-66-NH₂ was chosen for specific and sensitive detection of trace levels of hypochlorite. Hypochlorite causes the quenching of the blue fluorescence of nano-UiO-66-NH₂ (with excitation/emission maxima at 325/430 nm), and this finding forms the basis for a fluorometric assay for hypochlorite. The method overcomes disadvantages of conventional redox-probes which are interfered by oxidants with oxidation capability stronger than that of hypochlorite. Compared with other fluorescent probes for sensing hypochlorite, UiO-66-NH₂ has a comparable detection limit of 0.3 μmol L^-1 and a broad linearity relationship in the range of 1-8 μmol L^-1. The probe was successfully applied to the detection of hypochlorite in complex water samples and living Hela cells. Graphical abstract Schematic representation of hypochlorite induced quenching of the blue fluorescence of nano-UiO-66-NH₂ (with excitation/emission maxima at 325/430 nm) through energy transfer. It overcomes disadvantages of conventional redox-probes which are interfered by oxidants with oxidation capability stronger than that of hypochlorite.