Polymer-bound dirhodium tetracarboxylate films for fluorescent detection of nitric oxide

A polymer-bound dirhodium complex, [{Rh2(O2CCH3)3(Ds-pip)}n(O2C-P)], was prepared via ligand exchange of [Rh2(O2CCH3)4] with the side chains of a methyl methacrylate/methacrylic acid copolymer (O2C-P) followed by axial coordination of the fluorophore, N-dansylpiperazine (Ds-pip). Emission from Ds-pip is quenched when coordinated to the dirhodium complex but can be restored upon displacement by analytes. Exposure of [{Rh2(O2CCH3)3(Ds-pip)}n(O2C-P)] films to aqueous nitric oxide (NO) evokes a 2.2-fold increase in integrated emission. The polymer matrix excludes potentially interfering analytes including reactive oxygen or nitrogen species, which cannot readily permeate the film.