Fabrication of organically modified oxygen sensing film based on fluorescent quenching

An organically modified silicate (ORMOSIL) as a matrix for oxygen-sensitive sensor, in which di-methyldimethoxysilane was selected as an organic modifier in the precursor, is described. The sensing film with tris-(4,7-diphenyl-1,10-phenanthroline) ruthenium(II) as an indicator developed in this paper was characterized by efficient quenching by oxygen. Blue light-emitting diodes (λmax = 475 nm) were employed as light excitation source. The linear range of the dissolved oxygen was from 0.5 to 16 μg/mL. The measured RSD was 2%, the response time (t95) was 60 s, and the determination limit was 0.2 μg/mL. A portable and inexpensive luminescence-based sensor was established and applied to the determina-tion of dissolved oxygen in the surface water.