A multiresponsive luminescent hydroxyl-functionalized MIL-53(Al) for detection of F− and water

A luminescent hydroxyl-functionalized MIL-53(Al) (OH-MIL-53(Al)) was prepared by one-step solvent thermal method for multiresponsive fluorescence sensor. The OH-MIL-53(Al) exhibited uniform nanospheres with average diameter of 150±20 nm, flexible three-dimensional frameworks, and good dispersion in water. The OH-MIL-53(Al) emitted green fluorescence with a maximum wavelength of 515 nm which showed good fluorescence quenching response for sensing F − and fluorescence enhancement response for water, with good day-to-day stability. The mechanism was based on protonation/deprotonation of hydroxyl group located on OH-MIL-53(Al). Good linear relationship could be found between the luminescence intensity of 515 nm and F − concentrations in the range of 0–60 µM with a determination limit of 70 nM. At the concentrations from 0% to 100%, the fitting curve for water content was in good agreement with the linear equation, and the detection limit was 0.10%. OH-MIL-53(Al) demonstrated excellent fluorescence sensing performance, indicating that it could be used as a multiresponsive sensor to practical application.