新型荧光双重敏感响应性壳聚糖衍生物的合成及其发光性能研究

为了开发新型多功能天然高分子荧光材料，合成出一种新型含有环氧丙氧基荧光素(EPF)基团的水溶性壳聚糖衍生物GCS-EPF, 并用IR，1H NMR，UV光谱和荧光光谱等手段进行结构和发光性能的研究. 结果表明, 修饰后水溶性壳聚糖(GCS)的水溶液、 固体粉末和薄膜在520 nm附近具有较强的荧光发射, 其荧光强度不仅在0-60 ℃时对度有较快敏感响应， 同时在pH=0-13.5时对pH也有较快敏感响应， 具有双重敏感响应, 因此可将其作为温度荧光探针和pH荧光探针的高分子材料.

Synthesis and Luminescent Property of a Novel Fluorescent Dual Sensitive Chitosan

A novel method for attaching 3-epoxypropoxy fluorescein(EPF) to water soluble chitosan(GCS) and its dual sensitive quality of fluorescence were investigated. GCS bearing EPF was characterized by the methods of IR, 1H NMR, UV and fluorescence spectra, respectively. The chemiluminescent and photophysical behavior of GCS-EPF were studied, and the pH and temperature dependences of fluorescence of GCS-EPF were investigated in detail. From the results, we found that the emission wavelengths of GCS-EPF in solid and film states were larger than that in solution state, which may be due to the formation of an excimer between chromophore moieties on a chitosan chain. At 0-60 ℃, the maximum fluorescence intensity of GCS-EPF decreased on heating and the relationship between fluorescence intensity and the change of temperature was linear; At pH=0-13.5, its fluorescence intensity increased with basification and completely disappeared at very acidic pH.