Alternating current voltammetric determination of DNA concentrations at a microgram per liter level

Alternating current voltammetry is used as a fast and highly sensitive method of DNA detection, at a microgram per liter level. The method is based on the measurement of adsorption effects of denatured DNA at the hanging mercury drop electrode. The proposed procedure consists of thermal denaturation of DNA, which is followed by electrochemical detection of denatured DNA. A sharp adsorption peak of denatured DNA, at the potential of -1.4 V, is measured in 0.3 mol/liter NaCl and 0.03 mol/liter NaHCO3 (pH about 9) after an accumulation of DNA at the electrode surface. To enhance the sensitivity, the solution is stirred during adsorption. The influence of proteins, a polysaccharide, and RNA on the DNA determination was also studied.