荧光探针法研究壳聚糖在水溶液中的聚集态行为

本文用两种结构类似的分子内电荷转移化合物,3-羟基-6甲基-4-N,N-二甲氨基黄酮丙酸酯(PF)和3-甲氧基-4’-N,N-二甲氨基黄酮(DMMF),作为荧光探针,研究了壳聚糖在水溶液中的聚集状态.研究结果发现,当壳聚糖浓度增大到1×10^-3 kg/L或以上时,PF在430 nm处的荧光强度有一突增现象.利用DMMF作为荧光探针,研究了它在不同壳聚糖溶液中的稳态偏振,研究发现,随着壳聚糖浓度的增大,其偏振度也明显增大.这些结果进一步证实了壳聚糖在水溶液中的聚集特性,同时也为分子内电荷转移化合物——黄酮类化合物作为荧光探针研究生物大分子在水溶液中的构象提供了有益的尝试.

FLUORESCENCE PROBE STUDY OF CHITOSAN SELF-ASSOCIATION IN AQUEOUS SOLUTION

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.