Phosphorescence characteristics of ruthenium complex as an optical transducer for biosensors

摘要

The saturation intensity, photobleaching, and decay lifetime of tris(4,7-diphenyl-1,10-phenanthroline) ruthenium(Ⅱ) chloride [Ru(dpp)_3] are investigated. The saturation point was estimated to be 11.8 W/cm~2 and subsequently measured to be 11.5 W/cm~2. Photobleaching of this dye at a peak absorbance equivalence of 6.6 W/cm~2 is observed over 2 days resulting in a 14% decrease in intensity within 20 min and 47% decrease over two days yielding an unacceptably short operational lifetime under saturated conditions. Lower optical excitation levels in the application of oxygen sensitive fluorescence type fiber optic enzymatic biosensor systems are required and yield acceptable photobleaching rates.