Abstract: In this work, two kinds of intramolecular charge transfer compound,3-hydroxy-6-methyl-4’-N, N-dimethylamino flavone (PF) and 3-methoxy-4’-N, N-dimethylamino flavone (DMMF) were used to detect chitosan self association in aqueous solution. Results showed that when chitosan concentration was increased to 1×10³kg/L, the relative intensity of PF at 430nm had a sudden increase. In addition, the steady polarization of DMMF in chitosan solution was studied. The results showed that the polarization of DMMF increased with the increasing of chitosan concentration. It further indicated that chitosan in aqueous solution has the property of aggregation. In addition, this work provided a profitable experience for intramolecular charge transfer compound-flavone derivatives as fluorescence probe to study the configuration of biomacromolecule in aqueous solution.

Key words: fluorescence probe, chitosan, fluorescence polarization, self-association