Synthesis and application in PPE-based fluorescence chemosensor

Abstract

A series of polymers consisting of alternating oligo(p-phenyleneethynylene) chromophores and flexible oligo(ethylene oxide) segments were synthesized. Their solvent-induced and cation-induced aggregation behavior was established by optical and 1H NMR spectroscopic studies. Folding of the oligo(ethylene oxide) in the polymer backbone allowed effective O -O stacking of oligo(p-phenyleneethynylene) chromophores. Selective fluorescence quenching by Ca2+ was achieved in a solution of a polymer with a backbone of tetra(p-phenyleneethynylene) and penta(ethylene-oxide) in alternation. Atomic force microscopy (AFM) images of polymer deposited from solution indicated aggregation projecting perpendicular to the surface plane.