POLYMER-SUPPORTED PH SENSORS BASED ON HYDROPHOBICALLY BOUND LUMINESCENT RUTHENIUM(II) COMPLEXES

A new luminescence intensity-based sensor-polymer support system is de scribed. The pH-sensitive element is [Ru(phen)(2)[phen(OH)(2)]](2+) or [Ru(Ph(2)phen)(2)[phen(OH)(2)]](2+) (phen = 1,10-phenanthroline, Ph(2 )phen = 4,7-diphenyl-1,10-phenanthroline, and phen(OH)(2) = 4,7-dihydr oxy-1,10-phenanthroline) immobilized on a polymer built from a four-fu nction cyclic methyl siloxane ring polymer having (SiRCH3O)(4) units w ith poly(ethylene oxide) cross-linkers. Hydrophobic binding of the sen sor to the polymer is used to avoid the need for covalent chemistry. T hese sensor systems have a usable sensitivity over the 2-8 pH range, b ut are most usable in the 2-6 pH range. Response times for thick films (250 mu M) are rapid (several minutes).