A novel class of biocompatible, pH responsive bio-polymers is reported. Their functionality derives from multiple hydrophobic and hydrophilic groups along a flexible polymer backbone, which incorporates cy-3 and cy-5 dye monomers. Below a critical pH the polymer collapses (“hypercoils”) into a compact globular structure bringing the dye molecules into close proximity with one another. This results in a large increase in fluorescence resonance energy transfer (FRET) efficiency upon excitation of the cy-3 fluorophores in the molecule. Conformational and spectral properties of this novel class of fluorescent reporter molecules are discussed, as well as potential applications.
© 2004 Optical Society of AmericaPDF Article