One-Pot Trapping Luminescent Rhodamine 110 into the Cage of MOF-801 for Nitrite Detection in Aqueous Solution

Given to the severely toxic effect on aquatic organisms and serious carcinogen to human being of nitrite, the development of a convenient and sensitive method for its detection is of greatly significance. Herein, a novel Rh110@MOF-801 fluorescent probe was synthesized in a one-pot strategy and was successfully used in the determination of nitrite. This strategy, taking full advantages of fluorescent rhodamine 110 (Rh110) molecules and porous MOFs, could not only overcome the shortcomings of hydrophobicity of dye molecules and preserve its fluorescent properties perfectly, but also facilitate the interaction between nitrite and fluorescent recognition sites thanks to the open structure and good stability of porous MOFs. The results showed that the fluorescence quenching level of Rh110@MOF-801 fluorescent probe was linear with the applied nitrite concentration in the range of 2–7 µM with a limit of detection of 0.2 µM. Furthermore, the well-designed fluorescence probe could specifically recognize nitrite and would hardly be affected by other possibly coexistent interfering substances. It has been successfully used in quantitative detection of nitrite content in water samples mixed with interfering ions, prefiguring its great application potentials for nitrite monitoring.