A dual emission metal-organic framework for rapid ratiometric fluorescence detection of CO 3 2- in seawater.

A dual emission metal-organic framework (IRMOF-10-Eu) was prepared and used as a ratiometric fluorescent sensor for CO 3 2- detection. IRMOF-10-Eu had good stability and excellent luminescence in aqueous solution. IRMOF-10-Eu showed dual fluorescence emission from the ligand and Eu 3+ with single excitation. Upon treatment with CO 3 2- , the fluorescence ratio ( I 624 / I 358 ) of the probe displayed significant change. The relative fluorescence intensity ratio ( I 624 / I 358 ) and CO 3 2- concentration had a linear relationship in 50-300 μM range with a low detection limit of 9.58 μM. And the luminescence probe of CO 3 2- showed a fast detection time. The possible mechanism was investigated. CO 3 2- changed the structure of IRMOF-10-Eu and interrupted the energy transfer process. Thus, the fluorescence emission intensity of the ligand was increased and Eu 3+ was decreased with the addition of CO 3 2- . IRMOF-10-Eu was used to detect CO 3 2- in seawater, which showed good prospect in practical application. Subsequently, a highly selective and sensitive probe, IRMOF-10-Eu, may pave an efficient way for CO 3 2- detection in seawater.