An electrochemical DNA-biosensor for studying the interaction of carbaryl with natural double-stranded DNA (ds-DNA) was constructed. Layer-by-layer films of negatively charged natural ds-DNA and polycationic poly(diallyldimethylammonium chloride) (PDDA) were assembled on the surface of a glassy carbon electrode (GCE). The DNA intercalator [Ru(bpy)2(dppz)]2+ (bpy = 2, 2'-bipyridine, dppz = dipyrido[3, 2-a: 2',3'-c]phenazine) was chosen as an electrochemical probe. Tripropylamine (TPA) was used as an electron donor to chemically amplify the oxidation current of the probe. The interaction of naphthalene or a-naphthol with DNA were also studied by square wave voltammetry. The values of binding constant Kb of three compounds to DNA are determined, which were in the range of (0.2�105) to (1.3�105) M-1. The correlation suggests that the functional groups may play an important role in the DNA/analyte competition binding interaction. UV-absorption and fluorescence intensity of Ru-dppz were decreased in the presence of carbaryl. These characteristics strongly support the intercalation of carbaryl into double-stranded DNA.The authors thank the financial support from the Beijing Natural Science Foundation (No. 8102009), the Key Program of Science of and Technology of Beijing Municipal Education Commission (No. KZ201110005006).

Electrochemistry of the interaction of carbaryl with ds-DNA  using [Ru(bpy)<sub>2</sub>dppz]<sup>2+</sup> as probe

243rd National Meeting (2012)

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Electrochemistry of the interaction of carbaryl with ds-DNA using [Ru(bpy)2dppz]2+ as probe

Electrochemistry of the interaction of carbaryl with ds-DNA using [Ru(bpy)₂dppz]²⁺ as probe