A novel method for determination of DNA by use of molecular ‘Light Switch’ complex of Ru(bipy)2(dppx)2+ Original Research Article

A novel fluorimetric method was developed for selective determination of DNA with the molecular ‘Light Switch’ complex of Ru(bipy)2(dppx)2+. The maximum fluorescence intensity was produced in the pH range of 9.3–11.5, and the maximum excitation and emission wavelengths were 467 and 595 nm, respectively. Under the optimum conditions, the fluorescence intensity was in proportion to the concentration of DNA. The linear range for calfthymus DNA, Salmon sperm DNA and Herring sperm DNA were 0–0.4, 0–0.35 and 0–0.4 μg/ml, respectively. The limits of detection for Calfthymus DNA, Salmon sperm DNA and Herring sperm DNA were 0.75, 0.66 and 1.49, respectively. A satisfactory result was obtained when the proposed method was used to determine DNA in the presence of some coexisting substances.