Abstract:

The preparation and oxygen sensing properties of mesoporous materials DWM with a structure similar to that of MSU-type mesoporous materials based on covalently grafted Ru(bpy)²⁺₃ fragments through the Si—CH₂ covalent bonds were described in this paper. The 2,2'-bipyridyl covalently grafted to 3-aminopropyltriethoxysilane was used as one of the sol-gel precursor and the ligand of Ru(bpy)₂Cl₂·2H₂O complex to prepare the sol-gel derived silicates. The luminescence of the covalently grafted Ru(Ⅱ) luminophore within the mesoporous matrix can be extremely quenched by oxygen with a good sensitivity and rapid response time, which suggests that the covalently grafting strategy presented in this paper can be used to develop superior oxygen sensor. In addition, the mesoporous structure possesses a higher sensitivity than that of the amorphous one due to the inner porous channels of the mesoporous matrix favor the diffusion of oxygen, resulting in the higher sensitivity and shorter response time. Furthermore, the covalently grafting method possesses the distinct advantages over those physically entrapped methods due to the Si—CH₂ covalent bond, which greatly minimized the dye leaching effect and ensure the good stability.

Key words: Ruthenium complex, Covalently grafting, Oxygen sensor, Mesostructured molecular sieves