Utilization of Pyronine B as Voltammetric Probe for the Determination of DNA

Abstract

The electrochemical behaviors of the interaction of pyronine B (PB) with DNA were investigated on the mercury drop working electrode. In pH 2.0 Britton‐Robinson (B‐R) buffer solution, PB can be easily reduced on the mercury electrode and had a well‐defined voltammetric reductive wave at −0.86 V (vs. saturated calomelelectrode, SDE). On the addition of DNA into the PB solution, the reductive peak current of PB decreased with the positive movement of the peak potential and without the appearance of new peaks. The result showed that a new supramolecular complex was formed via intercalation of PB with DNA, which can't be reduced on the Hg electrode. The conditions of interaction and the electrochemical detection were carefully investigated. Under the optimal conditions the decrease of peak current was proportional to the concentration of DNA in the range of 1.0∼30.0 mg/L with the linear regression equation as ΔIp″(nA)=51.84C (mg/L)–94.97 (n=13, γ=0.993) and the detection limit was 0.90 mg/L. The interaction mechanism was discussed with the aggregation of DNA‐PB supramolecular complex and the stoichiometry of the supramolecular complex was calculated with the binding number as 3 and the binding constant as 1.61×1015.