双比率荧光分子印迹的制备及其可视化选择性检测邻苯二甲酸二甲酯的研究

Synthesis of ratiometric fluorescent molecularly imprinted polymers for selective determination of dimethyl phthalate

以异硫氰基荧光素(FITC)同SiO2基质通过硅烷偶联剂共价结合制备出了具有荧光性能的纳米级颗粒,并以其作为载体,烯丙基罗丹明B作荧光功能单体,通过表面印迹技术法合成了一种新型比率荧光分子印迹传感器(FMIPs-r/g-FITC/SiO2),并用于可视化选择性检测邻苯二甲酸二甲酯(DMP).其中烯丙基罗丹明B为信号响应单元,内核中FITC/SiO2荧光纳米粒子保持稳定作为参考背景内,通过利用烯丙基罗丹明B同DMP之间发生荧光猝灭效应,实现了对DMP的可视化选择性检测.所制备材料的平均粒径是150 nm,在0~100 nmol/L浓度范围内,与DMP的猝灭程度具有较好的线性关系,相关系数为0.99308,并且有着明显的视觉检测效果.双比率荧光分子印迹材料对DMP有较好的选择性,弥补了传统荧光传感器选择性方面的不足,同时具有高敏感性并使检测可视化.比率型荧光检测技术同分子印迹技术的联用,对检测技术的发展具有重要意义.

In this paper,fluorescein isothiocyanate(FITC)was covalently combined with a silica matrix through a silane coupling agent to prepare fluorescent nanoparticles as a carrier,and allyl rhodamine B was used as a fluorescent monomer.A novel ratiometric fluorescent molecularly imprinted polymers(FMIPs-r/g-FITC/SiO2)was prepared by the polymerization method for selective detection of dimethyl phthalate(DMP).Here,Allyl rhodamine B was a signal response unit,and FITC/SiO2 fluorescent nanoparticles in the core remain stable as a reference background.It was used to realize the visual detection of DMP via fluorescence quenching between allyl rhodamine B and DMP.The average particle size of the fluorescently imprinted material was 100 nm and had a linear fluorescent response in 0—100 nmol/L concentration range,the correlation coefficient was 0.99308 and had obvious visual detection effect.In addition,FMIPs show appreciable selectivity over several analogs.The ratiometric fluorescent molecularly imprinted material exhibits good selectivity for DMP,which makes up for the shortcomings of the selectivity of traditional fluorescent sensors,and has high sensitivity and visualizes the detection.The combination of ratiometric fluorescence detection technology and molecular imprinting technology can provide new ideas and approaches for the design of fluorescently imprinted materials.