Design and characterization of polymer matrix anchored to gold thin layer for the effective usage of evanescent field in SPR-based immunosensor

A remarkably stable antigen immobilization on gold thin layer deposited on a glass using aminoethanethiol and oxidized dextran hydrosulfate matrix is reported. The polymer was thus covalently bound onto the gold thin layer, and human serum albumin (HSA) as an antigen was covalently bound on the polymer matrix. The association and the dissociation of anti-HSA (aHSA) with the bound HSA were repeatedly observed by surface plasmon resonance (SPR) measurement. The SPR signal vs. concentration of aHSA has a good experimental agreement with the Langmuir adsorption isotherm equation of the aHSA binding with HSA.