Interaction of DNA with Direct Yellow 42 Dye by Spectroscopic Methods

Some chemical compounds such as the artificial colors used in various industries can have a bad effect on the health of the body. The most important biochemical molecule in the body is the DNA, that any change in its structure can affect all the living organism system. In this research for the first time, the interaction of the direct yellow 42 dye, which mainly used in the textile industry, with DNA was investigated by using Fluorescence, UV-Vis, FT-IR, and Circular Dichroism spectroscopy in the physiological buffer (pH~7.4) and at three temperatures 298, 308, and 318 K. The results obtained from absorption spectroscopy indicated that direct yellow 42 could bind to DNA at low concentrations. Thermodynamic parameters obtained from fluorescence experiments at different temperatures showed the hydrogen bonding and van der Waals force in the binding process of this dye with DNA. The binding constant (Kb) and binding site number were calculated. The results revealed that the quenching mechanism of EtBr-DNA with dye was a static type. Finally, the structural changes of DNA due to the direct yellow 42 dye were confirmed by FT-IR results. The results of this study can present a new look at the application of colors in the industry and the risks caused by their use.