Synthesis of Diketopyrrolopyrrole-Containing Conjugated Polyelectrolytes for Naked-Eye Detection of DNA

Two water-soluble cationic conjugated polyelectrolytes (P1 and P2) containing diacetylene, diketopyrrolopyrrole (DPP), and fluorene units were synthesized with Glaser-Hay coupling reaction as the key step. The narrow bandgap DPP units and the wide bandgap fluorene units in the cationic polyelectrolytes might form an energy donor-acceptor molecule architectures, in which DPP units serve as an acceptor of the fluorescent resonance energy transfer. The addition of calf thymus DNA enhances the fluorescent resonance energy transfer from fluoreneethynylene segments to DPP units, which results in a sensitive color change from blue to red in the PL spectra and allows naked-eye detection of DNA with low concentration. In addition, the detection of DNA with P1 and P2 is high selective because it is not interfered by common ions. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 3882-3889, 2011