制备了一种新颖的可对槲皮素分子进行选择性测定的分子印迹聚合物膜修饰电极。在碳纳米管(CNT)独特的结构和力学性能作用下,以吡咯(Py)为功能单体,槲皮素为模板分子,电聚合方法制备了槲皮素的分子印迹聚合物膜修饰电极(PPy/CNT/GCEMIP)。用电化学交流阻抗法研究了该修饰电极的界面性质,用循环伏安法和差分脉冲伏安法研究了槲皮素在修饰电极上的电化学行为。实验表明,该修饰电极能显著提高槲皮素的氧化峰电流,降低其氧化峰电位,并可在与其结构相似的桑色素等黄酮类物质的存在下,实现对槲皮素的选择性测定。在磷酸盐缓冲液(pH7.0)中,槲皮素的浓度在1.0×10^-7-1.0×10^-3mol/L范围内,其氧化峰电流与浓度存在良好的线性关系,检出限为5.5×10^-8mol/L。该修饰电极可用于含槲皮素成分药物的直接测定。
A molecularly imprinted polymer membrane modified electrode (PPy/CNT/GCEMIP ) was developed via the electrochemical polymerization of pyrrole in the presence of carbon nanb'tube and the molecular template quercetin(Qu). The electrochemical performance of PPy/CNT/GCEMIP was studied by electrochemical impedance speetroseopy(EIS). The electrochemical behaviors of Qu were investigated with cyclic voltammetry(CV) and differential pulse voltammetry (DPV) at the PPy/CNT/ GCEMIp. The results showed that a sensitive oxidation peak was observed at 0. 184 V in pH 7.0 PBS and the peak current was improved obviously, indicating that PPy/CNT/GCEMIP exhibited good eleetrocatalytie activity and enrichment towards Qu. Meanwhile, the PPy/CNT/GCEMIP displayed a high selectivity in vohammetric measurements of Qu in the presence of morin with an anodie peak separa- tion value of 263 mV by DPV. Under the optimal conditions, the oxidation peak current of Qu at the modified electrode was linear with the concentration over the range of 1.0 x 10 -7 _ 1.0 x 10-3 mol/L with a detection limit of 5.5 × 10^-8 mol/L. The relative standard deviation( RSD, n = 5 ) for 1.0 × 10^-4 mol/L Qu was 0.2% . With good stability, high selectivity, and wide linear range for the determination of Qu, PPy/CNT/GCEMIP could be applied in the determination of tablets containing Qu.