以咖啡因为模板分子,含菲环骨架的马来松香丙烯酸乙二醇酯为交联剂,甲基丙烯酸为功能单体,在玻碳电极表面以自由基热聚合的方式制备分子印迹聚合物敏感膜,构建了测定咖啡因的新型分子印迹膜电化学传感器.通过循环伏安法、差分脉冲伏安法及电化学交流阻抗法研究了传感器对咖啡因的响应特性.结果表明,在最佳的实验条件下,传感器的峰电流与咖啡因浓度在3.00×10^-3 ~2.73mmol/L范围内呈现良好的线性关系,检出限(S/N=3)为1.12×10^-4mmol/L.传感器具有良好的选择性和重现性.将该传感器用于可口可乐饮料中咖啡因含量的测定,平均回收率为98.7%.
A novel polymer based on the molecular imprinting technique was prepared using ethylene glycol maleie rosinate acrylate acid glycol ester as the cross-linker, caffeine as template and methyl acrylic acid as functional monomer. A molecularly imprinted polymer membrane was synthesized in vacuum drying oven by free radical polymerization. The electrochemical behavior of the membrane was characterized by cyclic vohammetry(CV) and electrochemical impedance spectroscopy(EIS). Under the optimal conditions, the peak currents and the analytical concentration have a good linear relationship over the range of 3.00 × 10^-3 to 2. 73 mmol/L(R=0. 9966) with a detection limit of 1.12×10^-4 mmol/L(S/N= 3). The electrochemical sensor dis- played excellent repeatability, high sensitivity, long-term stability, and good selectivity. The developed sensor was successfully applied to the determination of caffeine in coca-eola samples with average recovery of 98.7%.