IMMOBILIZATION OF RUTHENIUM TRIS-BIPYRIDYL COMPLEX FOR CHLORINE GAS-DETECTION

The fluorescence of tris-bipyridyl ruthenium complex (Ru-TRL) is sensi tive to changes in chlorine gas concentration through dynamic quenchin g processes. However, the use of TRL in conjunction with a fibre-optic -based sensing system depends on finding a suitable immobilization med ium for use with such a system. Several physical methods of immobiliza tion have been examined, namely, XAD 4, polyvinyl pyrrolidone (PVP) an d silicone rubber as suitable matrices, and it has been shown that the use of both PVP and silicone rubber as matrices for TRL allows the de sign of an optical sensor with rapid response to measure low chlorine gas concentrations. Limits of detection of 0.675 and 1 ppm have been p ossible using PVP and silicone rubber, respectively, as immobilization matrices under nitrogen atmospheres. Further studies have shown that the limit of detection for Ru-TRL in silicone rubber increased to 5 pp m under an atmosphere of air.