Adsorption of concanavalin A and lentil lectin on platinum electrodes followed by electrochemical impedance spectroscopy: effect of protein state.

Adsorption of concanavalin A and lentil lectin on platinum electrode was investigated through electrochemical impedance spectroscopy and cyclic voltammetry. By using ferro/ferricyanide system to probe the electrochemical interface it was possible to model the EIS data with a simple equivalent circuit. The blocking effect for electron transfer reactions observed with these proteins, indicated that they readily adsorb on platinum surface and that the degree of adsorption is related to the state of the proteins.

Impedimetric evaluation for diagnosis of Chagas' disease: antigen-antibody interactions on metallic electrodes.

A polypeptide chain formed by recombinant antigens, cytoplasmic repetitive antigen (CRA) and flagellar repetitive antigen (FRA) (CF-Chimera) of Trypanosoma cruzi, was adsorbed on gold and platinum electrodes and investigated by electrochemical impedance spectroscopy on phosphate buffer saline solutions (PBS) containing a redox couple. It was found that the adsorption is strongly sensitive to the oxide layer on the electrode surface. In the majority of the experiments the antigens retained their activity as observed through their interaction with sera from chronic chagasic patients.