Study on the Interaction between Epinephrine and DNA with Ag-doped-poly L-Proline Modified Electrode

Ag-doped-poly L-proline modified glassy carbon electrode (Ag-PPro/GCE) was prepared by electrochemical copolymerization of Ag+ and L-proline monomer on the surface of glassy carbon electrode by cyclic voltammetry, and the modified eletrode was applied to the study on the interaction between epinephrine (EP) and double strand DNA (dsDNA). It was found that in PBS of pH 7.0, a sensitive oxidation peak of EP was observed at the modified electrode; and the current of this oxidation peak decreased obviously upon addition of dsDNA. Linear relationship between the magnitude of decrease in peak current (Δi) of EP and mass concentration of dsDNA was kept in definite range. A complex between dsDNA and EP with the molar ratio of 1 to 2 was formed, with binding constant of 4.56×104.