Interactions of benzyl viologen with surface-bound single- and double-stranded DNA.

摘要: The interactions of benzyl viologen (BV) with single- and double-stranded calf-thymus DNA immobilized onto gold electrodes have been studied by electrochemical methods. Benzyl interacts electrostatically both (ds) single-stranded (ss) DNA, the strength is dependent on ionic (μ). dicationic form (BV2+) binds to dsDNA 9 times more strongly than singly reduced form, BV•+, in a pH 7.4 Tris-HCl buffer solution at μ = 8.4 mM. BV2+ ssDNA 5 BV•+ form. From measurements mM, binding constant (K2+) 2.0 (±0.2) × 104 M-1 site size (s) 1 base pair were obtained, respectively, for dsDNA. For ssDNA, same strength, values obtained K s 3.6 (±0.4) 2 nucleotides, respectively. amount BV bound, whether or decreased increasing strength. Whereas rate onto...