The interaction of taurine–salicylaldehyde Schiff base copper(II) complex with DNA and the determination of DNA using the complex as a fluorescence probe

Abstract

The interaction of taurine–salicylaldehyde Schiff base copper(II) (Cu(TSSB) 2 2+) complex with DNA was explored by using UV–vis, fluorescence spectrophotometry, and voltammetry. In pH 7.4 Tris–HCl buffer solution, the binding constant of the Cu(TSSB) 2 2+ complex interaction with DNA was 3.49 × 10 4 L mol −1. Moreover, due to the fluorescence enhancing of Cu(TSSB) 2 2+ complex in the presence of DNA, a method for determination of DNA with Cu(TSSB) 2 2+ complex as a fluorescence probe was developed. The fluorescence spectra indicated that the maximum excitation and emission wavelength were 389 nm and 512 nm, respectively. Under optimal conditions, the calibration graphs are linear over the range of 0.03–9.03 μg mL −1 for calf thymus DNA (CT-DNA), 0.10–36 μg mL −1 for yeast DNA and 0.01–10.01 μg mL −1 for salmon DNA (SM-DNA), respectively. The corresponding detection limits are 7 ng mL −1 for CT-DNA, 3 ng mL −1 for yeast DNA and 3 ng mL −1 for SM-DNA. Using this method, DNA in synthetic samples was determined with satisfactory results.