Flow Injection Analysis of Immunoglobulin G Using Surface Plasmon Resonance Sensor

Original Paper

Abstract

Direct detection of immunoglobulin G (IgG) by using a surface plasmon resonance (SPR) sensor through an antigen‒antibody interaction was described. An anti‒IgG antibody was chemically immobilized on a sensor chip through a self‒assembled monolayer (SAM) in order to enhance the recognition of an IgG antigen. By assuming the Langmuir adsorption isotherm, maximum amount of adsorbed anti‒IgG antibody on the sensor chip and an apparent biding constant of the IgG antigen to anti‒IgG antibody were estimated. The amount of the IgG antigen bound to the anti‒IgG antibody, which was immobilized onto the sensor chip through the SAM was three times higher compared with the amount of the IgG antigen bound to the anti‒IgG antibody, which was immobilized directly to the sensor chip through physical adsorption.