Spectroscopic and Electrochemical Studies on The Binding Mechanism of DNA With an Anthraquinone Biological Dye, Nuclear Fast Red

Abstract

In this work, the interaction of an anthraquinone dye, nuclear fast red (NFR) with fish-sperm DNA was studied via spectrometry, viscometry and electrochemical methods. A weak hypochromic effect was observed for the characteristic absorption peaks of NFR, and its wavelengths had no shift in the presence of DNA, showing the external binding mode of NFR to DNA. The fluorescent spectra experiments showed that DNA could quench the emission spectra of NFR with a moderate Stern–Volmer quenching constant (Ksv) of 1.5× 103 M-1, which was also consistent with an external binding mode. DNA viscosity experimental results further suggested that NFR did not intercalate into the base pairs of DNA. Electrochemical method was also applied to study the interaction between NFR and DNA, and the binding constant (K) and binding site size (s) of NFR with DNA were determined to be 3.3×105 M-1 and 3.5, respectively, based on voltammetric titration method.