ZrO2 gel-derived DNA-modified electrode and the effect of lanthanide on its electron transfer behavior

A new method of immobilizing deoxyribonucleic acid (DNA) was developed based on sol–gel technique, the resulting DNA-modified electrode was characterized with the cyclic voltammetry. The electrode was used to study the electron transfer of DNA in 1.0 mM potassium ferricyanide system in different concentrations of lanthanum(III), europium(III), and calcium(II). The heterogeneous rate constants of the reduction of Fe(CN)63− with and without the above cations were calculated by Tafel equation. The results show that lanthanide ions can increase the electron transfer rate much more than calcium ion.