Photoluminiscence response of Ru(II) complex immobilized in SiO2-based matrix to dissolved oxygen in beer

The possibility to use the photoluminescence of Ru(II) tris(4,7-diphenyl-1,10-phenathroline) dichloride, immobilized in sol–gel produced SiO2-based matrix for the determination of dissolved oxygen concentration in beer is studied. Organically-modified silane (octyltriethoxysilane) and mixtures from tetraethoxysilane and octyltriethoxysilane are used as precursors for matrix production. Spin- and dip-coating techniques are applied for films deposition. The predeposition ultrasound treatment of the sol ensures a good sensitivity and a linear sensor quenching response to oxygen in 1 ÷ 6 ppm O2-concentration interval. The CO2 present practically has no effect on the films performance. Their photoluminescence show rather good stability on prolonged storage in beer.