Quenching of the Electrochemiluminescence of Tris(2,2‘-bipyridine)ruthenium(II) by Ferrocene and Its Potential Application to Quantitative DNA Detection

• Published in: Journal of the American Chemical Society 2006-06, Vol.128 (23), p.7572-7578
• Main Authors: Cao, Weidong, Ferrance, Jerome P, Demas, James, Landers, James P
• Format: Article
• Language: English
• Subjects: 2,2'-Dipyridyl - analogs & derivatives; 2,2'-Dipyridyl - chemistry; Analytical, structural and metabolic biochemistry; Base Sequence; Biological and medical sciences; DNA - analysis; Dna, deoxyribonucleoproteins; Electrochemistry; Electrodes; Ferrous Compounds - chemistry; Fundamental and applied biological sciences. Psychology; Indicators and Reagents - chemistry; Luminescent Measurements - instrumentation; Luminescent Measurements - methods; Metallocenes; Molecular Sequence Data; Nucleic acids; Sensitivity and Specificity
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja060162g

Efficient and stable quenching of electrochemiluminescence (ECL) of tris(2,2‘-bipyridine)ruthenium(II) by oxidizing ferrocene methanol (FcMeOH) at the electrode is reported. Bimolecular energy or electron transfer between Ru(bpy)3 2+* and ferrocenium (Fc+), the oxidized species of Fc, along with suppression of radical reactions is suggested as the mechanism for quenching ECL. Fc shows more efficient quenching of ECL compared with the known quenchers phenol and 1,1-dimethyl-4,4‘-bipyridine dication (MV2+). The ECL quenching rate constant was 5.6 × 1010 M-1 s-1. Using Fc as a quencher label on a complementary DNA sequence, an intramolecular ECL quenching in hybridized oligonucleotide strands has been realized. With essentially complete quenching efficiency, this system has the potential for application to sequence-specific DNA detection.