The performance of oxygen sensing films with ruthenium-adsorbed fumed silica dispersed in silicone rubber

Oxygen sensing films were prepared by adsorbing the his(4,7-diphenyl-1,10-phenanthroline)ruthenium dye onto high surface area hydrophilic fumed silica and dispersing the ruthenium-loaded silica in a silicone rubber support. These sensing films possess desirable properties including higher luminescence intensity, larger response towards oxygen and more linear Stern-Volmer calibration curves than films prepared by simple mixing of the ruthenium dye with silicone rubber. However, the response time of these silica-containing films in the recovery cycle is ca. 30-50% longer than the films without silica.