Electrochemical study of interaction between clozapine and DNA and its analytical application

The interaction between clozapine (CLZ) as an orally administrated antipsychotic drug with double stranded calf thymus DNA (dsDNA) was investigated at electrode surface using differential pulse voltammetry (DPV). Activated carbon paste electrode (CPE) was modified with dsDNA and used for monitoring the changes of the characteristics peak of CLZ in 0.05 M acetate buffer (pH 4.3). The adsorptive stripping voltammetry on dsDNA-modified carbon paste electrode (dsDNA-CPE) was used for determination of very low concentration of CLZ. Under optimal conditions, the oxidation peak current is proportional to CLZ concentration in the range of 7 x 10(-9) -1.2 x 10(-6) mol 1(-1) with a detection limit of 1.5 x 10 (-9) mol(-1) for 180 s accumulation time by DPV. The proposed dsDNA-CPE was successfully used for determination of CLZ in human serum samples with recovery of 97.0 +/- 2.5%.