一种罗丹明内酰胺类高分子pH荧光探针的合成及性能

Synthesis and properties of a Rhodamine lactam-based polymeric pH fluorescent probe

用罗丹明B、丙烯酰胺等为主要原料,设计制备出一种高分子pH荧光探针PRAM,在结构表征的基础上,探究此探针的光物理性质和活细胞的荧光成像。结果表明,探针PRAM的pKa为4.30,在pH为3.0~7.0区间内,对H+表现出高度灵敏性和选择性,可实时监测体系pH变化。在pH为5.0~6.0区间内,其585nm下的荧光强度与pH呈现出良好的线性关系,线性相关系数为0.9955,可用来精确测定体系的pH。在常见的金属离子存在下,PRAM表现良好的抗干扰性和选择性。同时还具备很好的可逆性,可重复利用。PRAM具有良好的水溶性和膜透性,弱酸性条件下可快速穿透细胞膜,并能实现活细胞pH变化的荧光成像。因此,可用于弱酸环境下细胞器(如溶酶体、癌细胞等)内生理pH变化的检测。

A class of polymeric pH fluorescent probe PRAM was designed and prepared using Rhodamine B and acrylamide as the main raw materials.The structure of PRAM was characterized.The photophysical properties of this probe and the fluorescence imaging of living cells were investigated.The experimental results showed that the pKa value of the probe was 4.30,and it had high selectivity and sensitivity to H+in the pH range of 3.0—7.0,allowing real-time monitoring of system pH changes.Furthermore,its fluorescence intensity at 585 nm showed a good linear relationship with pH in the pH range of 5.0—6.0,with a linear correlation coefficient of 0.9955,which could be used to accurately determine the pH of the system.PRAM still performed well in terms of interference resistance and selectivity in the presence of common metal ions.PRAM had good water solubility and membrane permeability,allowing rapid penetration of cell membranes under weakly acidic conditions,and enables fluorescence imaging of pH changes in living cells.Therefore,it could be used to detect physiological pH changes within organelles(e.g.,lysosomes,cancer cells,etc.)in a weakly acidic environment.