Study on the toxic interactions of Ni2+ with DNA using neutral red dye as a fluorescence probe

The interaction between Ni2+ and calf thymus DNA (ctDNA) was investigated in simulated physiological buffer (pH 7.4) using the Neutral Red (NR) dye as a spectral probe by UV–vis absorption and fluorescence spectroscopy, as well as CD spectra. The experimental results showed that the conformational changes in DNA helix induced by Ni2+ are the reason for the fluorescence quenching of the DNA–NR system. From the experimental results, conclusion can be drawn that Ni2+ can cause structural changes of ctDNA and bind with DNA by electrostatic interaction. At the same time, the paper proved that conformation changes of DNA can also lead to the fluorescence decrease of DNA–probe systems.