A Novel Magnetism‐assisted Electrochemical Immunosensor with Sub‐Picomolar Sensitivity

Abstract

A novel electrochemical immunosensor based on a magnetic glassy carbon electrode (MGCE) was developed for the quantitative determination of human immunoglobulin G (IgG). The immunosensing interface was fabricated by initially depositing silver nanoparticles on the MGCE surface and then immobilizing anti‐human IgG antibodies via the magnetic force between MGCE and Fe3O4 nanoparticles. The antibodies were covalently bonded to the amine‐functionalized Fe3O4 nanoparticles. Under optimal conditions, the magnetism‐assisted immunosensor exhibited a wide linear range from 0.1 pg/mL to 1.0 µg/mL with the detection limit of 0.05 pg/mL. Furthermore, the immunosensor displayed the advantages of good reproducibility and satisfactory stability.