A bis(2,2′-Bipyridine) (Dipyrido[3, 2-a:2′ 3′-c]Phenazine-N4N5) Ruthenium(II)-Based Electrochemiluminescence Biosensor for Evaluation of DNA Damage

Abstract

The electrochemiluminescence of bis(2, 2′-bipyridine) (dipyrido[3, 2-a:2′ 3′-c]phenazine-N4N5) ruthenium(II) ([Ru(bpy)2(dppz)]2+) was used to monitor deoxyribonucleic acid (DNA) charge transfer with tri-n-propylamine as a coreactant. This system was used to measure damage to DNA induced by perfluorooctanoic acid. Fifteen-base pairs of double-stranded DNA with a thiol group at the 5′ end position were covalently bonded to a gold electrode. An electrochemiluminescence sensor was then constructed by incubating the modified gold electrode in [Ru(bpy)2(dppz)]2+ solution for 30 min. For comparison, single-stranded DNA, well-matched double-stranded DNA, and single base-mismatched double-stranded DNA were assembled on the gold surface. The results showed that the electrochemiluminescence behavior of the DNA sensors were unique. The electrochemiluminescence decreased when the [Ru(bpy)2(dppz)]2+-DNA ECL sensor was incubated in a perfluorooctanoic acid solution. The damage to DNA caused by perfluorooctanoic acid was monitored using a combination of DNA charge transfer theory and the interaction between DNA and [Ru(bpy)2(dppz)]2+. The detection limit for perfluorooctanoic acid was 1 × 10−12 mol/L. [Ru(bpy)2(dppz)]2+ was shown to be a sensitive electrochemiluminescence sensor for the determination of DNA damage.