Luminescence quenching behavior of oxygen sensing ORMOSIL films based on ruthenium complex

Abstract

An organically modified silicate (ORMOSIL) based optical sensor response to gaseous O-2 or O-3 dissolved in water is presented. The oxygen sensing film mechanism is based on the principle of fluorescence quenching of tris(4,7-diphenyl-1,10-phenanthroline) ruthenium (II) ([Ru(dpp)(3)](2+)), which has been entrapped in a porous ORMOSIL film. In order to establish optimum film-processing parameters, comprehensive investigations, including the effects of the polarity and the hydrophobicity of the sensing film on oxygen quenching response and response time, were carried out. The film hydrophobicity increased as a function of dimethyl-dimethoxysilane (DiMe-DMOS) content, which is correlated with enhanced oxygen sensor performance. The sensor developed in the present work exhibits the advantages of fast response time and good reversibility. The detection limits are 0. 5 % and 0. 3 mug/mL for O-2 in the gaseous and the aqueous phases, respectively.