Luminescent pH sensing and DNA binding properties of a novel ruthenium(II) complex

Abstract

A new Ru(II) complex, [Ru(bpy) 2(dhipH 3)](ClO 4) 2 (in which bpy=2,2 ′-bipyridine, dhipH 3=3,4-dihydroxy-imidado[4,5- f][1,10]-phenanthroline), was synthesized and characterized, and the pH effect on the emission spectra of the complex was studied. The interaction of the complex with calf thymus DNA was investigated by UV–visible and emission spectroscopy, and viscosity measurements. The results suggest that the complex acted as a sensitive luminescent pH sensor and a strong ct-DNA intercalator with an intrinsic binding constant of (4.0 ± 0.7) × 10 5 M −1 in buffered 50 mM NaCl.