Ratiometric Fluorescent Detection of ClO- Based on Dual-Emission F1-Rubpy@Nanoscale Metal-Organic Frameworks

Herein, a facile one-pot strategy was developed to synthesize novel dual-emission nanoscale ZnMOF74 encapsulating with fluorescein o-acrylate (F1) and tris(2,2'-bipyridyI)-dichroruthenium(II) hexahydrate (Rubpy) (F1-Rubpy@ZnM0F74). The asprepared dual-emission F1-Rubpyg ZnMOF74 nanocomposites were characterized by scanning electron microscopy, X-ray powder diffraction, N-2 adsorption/desorption isotherms and fluorescence techniques. The results showed F1-Rubpy@ZnM0F74 nanocomposites were spherical with diameter of 100-300 nm, and exhibited good water dispersion. F1 and Rubpy were uniformly encapsulated in the pores of ZnMOF74. The nanosensor displayed strong emission peaks of F1 at 512 nm and Rubpy at 600 nm. The l(512nm)/l(600nm) decreased with increasing concentration of CIO- in the range of 3.6 nM-100 mu M with low detection limit of 1.2 nM. The nanocomposites also showed high sensitivity, selectivity and stability, which was expected to apply in quality testing of industrial goods and further biological cell experiments. The work also provides a good method to construct ratiometric fluorescent sensors based on MOFs.