A carboxylic acid-functionalized polyfluorene as fluorescent probe for protein sensing.

A new water-soluble fluorescent conjugated polyelectrolyte, poly[9,9-bis(3′-butyrate)fluoren-2,7-yl] sodium (BBS-PF), was studied as a fluorescent probe for protein sensing. The conjugated polyelectrolyte BBS-PF shows high fluorescence sensitivity to cytochrome c, lysozyme, and bovine serum albumin (BSA). The Stern-Volmer constant ( K) in cytochrome c was measured to be as high as 6.1 × 10 L/mol, approximately twice as that of the other two. Interestingly, it is found that BSA slightly enhances the fluorescence of BBS-PF rather than quenches the fluorescence at its micromolar concentrations. The excitation spectra confirm that the interaction of BBS-PF with the proteins could be different. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 [ABSTRACT FROM AUTHOR]