Fig. 3.

Square wave voltammograms for gold disk electrode modified with ssDNA (a); unmodified electrode (b). (I) Analysis in 50 mmol L⁻¹ Tris buffer solution, pH 3.0; (II) analysis in 50 mmol L⁻¹ Tris buffer solution, 3.0, containing 50 μmol L⁻¹ methylene blue; (III) analysis in 50 mmol L⁻¹ Tris buffer solution, pH 3.0, containing 50 μmol L⁻¹ methylene blue and 1 mmol L⁻¹ uranyl acetate