Electrochemical and Spectral studies on the Interaction of the Antiparasitic Drug Nitazoxanide with DNA

The interaction of the antiparasitic drug nitazoxanide (NTZ) with salmon sperm double strand deoxyribonucleic acid (ss-ds-DNA) has been studied using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) at screen printed carbon electrode (SPCE). NTZ shows two irreversible oxidation peaks measured in 0.02 M phosphate buffer (pH 4.0 and 7.4). UV/Vis spectroscopy was also employed to probe the interaction between NTZ and ss-ds-DNA. From the CV data, the diffusion coefficients were found as 5.1 × 10−7 and 4.9 × 10−9 cm2s−1 for NTZ and NTZ-DNA, respectively. Based on the CV and spectroscopic results, the binding constant between NTZ and DNA was calculated to be 4.1 × 105 M−1 and 5.0 × 105 M−1, respectively. The interaction as a sum of intercalation and groove binding modes was concluded. A procedure for the differential pulse voltammetric determination of NTZ at a screen-printed electrode surface modified with the ss-ds-DNA layer was also described. The method was applied for the determination of NTZ in spiked serum.