罗丹明B表面分子印迹聚合物制备及其荧光检测

Preparation and Fluorescence Microscopic Characterization of Surface Molecularly Imprinted Polymer of Rhodamine B

以罗丹明B为模板分子,制备了一种基于氧化硅的表面分子印迹聚合物,并采用扫描电镜对表面分子印迹聚合物的性状进行检测,证明表面分子印迹聚合物是在硅胶表面形成了印迹空穴。同时,使用荧光显微镜检测证明罗丹明B可被表面分子印迹聚合物有效结合和快速洗脱。采用荧光分光度计检测表面分子印迹聚合对底物结合能力和特异性,结果显示,表面印迹聚合物对罗丹明B具有高的识别性能,其Kd值为163.6,而相似物罗丹明6G和丁基罗丹明B分别为50和54.5。该方法与传统罗丹明B检测方法(高效液相色谱-紫外检测法)相比更为灵敏,检测限更低,即0.1 mg/L,可检测出痕量物质。

Poly(methacrylic acid) was grafted onto the surface of bulk SiO2 by solution polymerization to produce a molecularly imprinted polymer with a two-layer PMAA/SiO2 bulk structure(surface molecularly imprinted polymer, SMIP). The morphology of SMIP was characterized by scanning electron microscopy(SEM) and fluorescence microscopy(FM). The SEM image demonstrated that imprinted cavities were formed on the surface of SMIP. The FM image showed that rhodamine B(Rh B) could be combined and eluted quickly and effectively. SMIP had better binding property and selectivity as detected by a fluorescence spectrophotometer. The Kd of Rh B was 163.6, which was higher than that(50 and 54.5, respectively) of Rh 6G and butyl Rh B. Compared with the traditional detection method(HPLC-UV), the molecular imprinting method had better sensitivity and lower detection limit(0.1 mg/L) for trace-level determination of Rh B.