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.
ABSTRACT
This paper reports investigations into the preparation and characterization of surface molecularly imprinted nanoparticles (SMINs) designed to adhere to Helicobacter pylori (H. pylori). Imprinted nanoparticles were prepared by the inverse microemulsion polymerization method. A fraction of Lpp20, an outer membrane protein of H. pylori known as NQA, was chosen as template and modified with myristic acid to facilitate its localization on the surface of the nanoparticles. The interaction between these SMINs with the template NQA were evaluated using surface plasmon resonance (SPR), change in zeta potential and fluorescence polarization (FP). The results were highly consistent in demonstrating a preferential recognition of the template NQA for SMINs compared with the control nanoparticles. In vitro experiments also indicate that such SMINs are able to adhere to H. pylori and may be useful for H. pylori eradication.