Detection of Interaction Between Metal Complex Indicator and DNA by Using Electrochemical Biosensor

Abstract

There has been extensive research on binding of transition metal complexes to DNA via electrostatic and hydrophobic interactions. Most indicator based electrochemical DNA biosensors have used cationic metal complexes that interact in a different way with single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA). Described here are the electrochemical parameters for a mixed-ligand complex, [Co(phen) 3 3 ] (phen: 1,10-phenanthroline), on binding to DNA. The milimolar quantities of [Co(phen) 3 3 ], which associates reversibly with immobilized calf thymus DNA was detected by using dsDNA-modi®ed carbon paste electrode (dsDNA-modi®ed CPE), ssDNAmodi®ed carbon paste electrode (ssDNA-modi®ed CPE) and bare carbon paste electrode (bare CPE), voltammetrically and the decreased peak currents were observed, respectively. The extend of hybridization between the complementary sequences is determined by the enhancement of the voltammetric peak of the [Co(phen) 3 3 ] indicator. Numerous factors affecting the DNA immobilization and indicator were investigated. Experiments were also performed at various salt concentrations and the optimum salt concentration was determined. The difference between the peak currents of denaturated calf thymus DNA (ssDNA)-modi®ed CPE and dsDNA-modi®ed CPE was also observed. These results demonstrated the use of the electroactive hybridization indicator, [Co(phen) 3 3 ] for DNA biosensors.

Voltammetric study of interaction of Co(phen)33+ with DNA at gold nanoparticle self-assembly electrode

“…, arsenic trioxide, and methylene blue with DNA [14][15][16]. J. J. Gooding et al have studied an interaction of 2, 2 EA#ST04-138 1st Resubmitted Version 6-disulfonic acid anthraquinone with DNA as an intercalator [17].…”

Detection of Antioxidative Activity of Plant Extracts at the DNA-Modified Screen-Printed Electrode

“…Voltammetric behavior of [Co(phen) 3 ] 3+ at the DNA-modified gold electrode [24], glassy carbon electrode [20], carbon paste electrode [25,26] as well as carbon-based screen-printed electrode [18,19] was reported previously. After the accumulation of the marker at DNA/SPE under the open circuit conditions, a good developed DPV peak of the complex appears at -0.130 V vs Ag/AgCl (Fig.…”

Detection of short oligonucleotide sequences using an electrochemical DNA hybridization biosensor

“…DNA hybridization biosensors can be employed for determining early and precise diagnosis of infectious agents in various environments [2,3] and these devices can be exploited for monitoring sequence-specific hybridization events directly [4,5] or by DNA intercalators (metal coordination complexes, antibiotics, etc.) which form complexes with the nitrogenous bases of DNA [6][7][8][9][10][11][12]. Electrochemical transducers offer a very attractive route for converting the hybridization event into a useful analytical signal [13][14][15][16].…”