Citation: ZHAO Cheng-Jun, MA Xiong-Hui, Li Jian-Ping. An Insulin Molecularly Imprinted Electrochemical Sensor Based on Epitope Imprinting. Chinese Journal of Analytical Chemistry, 2017, 45(9): 1360-1366. doi: 10.11895/j.issn.0253-3820.170256 [复制]
An Insulin Molecularly Imprinted Electrochemical Sensor Based on Epitope Imprinting
采用抗原决定基法制备了胰岛素电化学分子印迹传感器。以胰岛素C端多肽作为模板分子，定向自组装在Au电极上，以邻苯二胺为功能单体，电化学聚合制备分子印迹聚合膜。以NaOH为洗脱液，洗脱模板分子，形成的与胰岛素C端多肽三维结构相匹配的分子印迹孔穴能特异性识别胰岛素。重吸附胰岛素分子后，以K3[Fe（CN）6]/K4[Fe（CN）6]为探针，通过测量探针在电极表面产生的电流大小实现胰岛素的间接测定。在1.0×10-14~5.0×10-13 mol/L浓度范围内，传感器的电流响应值与胰岛素浓度呈良好的线性关系，检出限为7.24×10-15 mol/L（3σ）。此传感器具有较好的选择性和稳定性，并成功用于血清样品中胰岛素的测定。
A novel molecularly imprinted electrochemical sensor for direct detection of insulin was prepared based on epitope imprinting. C-Terminal polypeptide in insulin as template molecule was firstly self-assembled on the Au electrode. Then the molecularly imprinted polymer (MIP) was fabricated by electropolymerization with o-phenylenediamine (o-PD) as functional monomer on this Au electrode. After elution of template molecules by NaOH solution, the imprinting cavities were formed with the three-dimensional structure matched with the polypeptide in insulin molecules. The imprinting cavities could specifically recognize and rebind with insulin molecules. With K3[Fe(CN)6]/K4[Fe(CN)6] as a probe, the insulin was indirectly detected. There was a linear relationship between the response current and the insulin concentrations in the range of 1.0×10-14-5.0×10-13 mol/L, and the detection limit was 7.24×10-15 mol/L. The developed sensor exhibited good selectivity and stability, and could be applied to the determination of serum samples.