Development of a Ca²⁺‐Sensitive Electrostatic Self‐Assembly Films for the Fabrication of Reproducible Immunosensor

Abstract

A novel strategy for fabricating reproducible immunosensor has been developed by employing the merits of Ca²⁺‐induced cross‐linkage of sodium alginate and negative‐carboxyl groups of alginate. The alginate was used to modify the gold electrode and render the gold electrode negative charge to immobilize antibodies via electrostatic interaction between carboxyl groups on alginate and amino groups on antibodies to realize the fabrication of immunosensor in 0.01 mol/l pH 7.5 acetic‐acetate buffer solution. The Ca²⁺‐induced cross‐linkage of alginate on the immnosensor can release antibodies from electrode and regenerate one fresh alginate‐modified electrode for the fabrication of new immunosensor. The feasibility of the proposed strategy and qualities of the fabricated immunosensor was evaluated by being applied to a competitive transferrin‐transferrin antiserum immunoassay system.

Keywords:

• Alginate
• Ca²⁺‐induced cross‐linkage
• electrostatic
• reproducible immunosensor
• electrochemical

This work is financially supported by the Foundation for Hunan Province Young Scholar (Grants No: 05B075). Thanks to Prof. Rong Tai from XianYa Hospital, Changsha, for his kind work on transferrin ELISA.