Three polar poly(para-phenylene ethynylene)s (PPE) were synthesized by utilizing the Heck-Sonogashira protocol. Two of the PPEs carry beta-glucopyranose substituents. Depending upon the linker used between the glycol units and the backbone, the fluorescence of these PPEs can be quenched by Hg2+ and Pb2+ to a varying degree. Monomeric model compounds that are substituted with only one glucose unit are not efficiently quenched. The presence of many glucose substituents in one PPE assembly led to a large increase in the binding constant to Hg2+ and quenching of the fluorescence was amplified.

The interaction of a mannose-substituted poly(para phenyleneethynylene) (mPPE) with a lectin, Concanavalin A (ConA), is reported; the ConA causes fluorescence quenching of the mPPE with a K(SV) of 5.6 x 10(5).

The synthesis and spectral characterization of three grafted poly(p-phenyleneethynylene)s (PPE) are reported. These polymers contain identical chromophores/fluorophores yet show different absorption and emission spectra in DMF and DMF−water mixtures. While some of the spectral properties of the PPEs are similar to those of didodecyl-PPE, their spectroscopic properties in DMF−water mixtures differ significantly from those of didodecyl-PPE in CHCl3. An example is the lactide-substituted PPE, which shows absorption spectra that are reminiscent of those obtained for didodecyl-PPE in poor solvents but emission spectra that resemble those of didodecyl-PPE in a good solvent. Emission shifts occur in these PPEs when going from DMF to water. In the case of the lactide-PPE, a surprising hypsochromic emission shift of 10 nm is observed. This apparent shift is attributed to the preferred aggregation and self-quenching of the longer chains, leaving shorter, blue-emissive chains nonaggregated.