Impedance sensing of allergen–antibody interaction on glassy carbon electrode modified by gold electrodeposition

The interactions between the recombinant dust mite allergen Der f2 and murine monoclonal antibody were monitored by electrochemical impedance spectroscopy (EIS). Allergen Der f2 were immobilized through the nanogold formed by electrodeposition of gold on planar glassy carbon electrode. A 30-s gold electrodeposition provided a desirable substrate for the immobilization of allergen. Electrochemical deposition of gold on a glassy carbon electrode showed significant improvement in allergen immobilization. The impedance measurements were based on the charge-transfer kinetics of the [Fe(CN)6]3−/4− redox pair. The interactions between allergen and antibody occurred on electrode surface altered the interfacial electron transfer resistance, RCT, by preventing the redox species approaching the electrode. The results showed that RCT increased with increasing concentration of monoclonal antibodies.