Chemically modified dansyl probes: a fluorescent diagnostic for ion and proton detection in solution and in polymers.

[reaction: see text] The fluorescence emission intensity of the dansyl group is significantly diminished upon appending an ethyldimethylamino group to the N1 nitrogen substituent. Addition of acids and metal ions (i.e., Zn(2+)) to solutions of trimethylethylenediamine naphthalene sulfonamide (trinsyl) 2 produces a >25-fold increase in fluorescence intensity. Trinsyl probe 2 has been used as a diagnostic for the diffusion of protons and metal ions in a network polymer as well as an optical reporter for the glass transition temperature.