Figure 3. (А) DVPs SPE/fCNT/TiO2 of various dsDNA concentrations. 100 mM potassium phosphate buffer with 50 mM NaCl as supporting electrolyte, pH 7.4. Accumulation potential of 0,4 V, time accumulation of 15 min, pulse amplitude of 0,025 V, step capacity of 0,005 V, interval time of 50 ms, modulation amplitude of 0,05 V. All potentials were referred to the Ag/AgCl reference electrode. (B) Calibration curve of peak currents against dsDNA concentrationfor guanine. (C) Calibration curve of peak currents against dsDNA concentration for adenine. (SPE – screen-printed electrode, fCNT – functionalized carbon nanotubes).