An Insulin Molecularly Imprinted Electrochemical Sensor Based on Epitope Imprinting / 分析化学

ABSTRACT

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.