Binding and Toxicological Insights into Direct Yellow 8 and Bovine Serum Albumin: Fluorescence Quenching and Cytotoxicity Studies

The present work elucidates the binding interaction between the textile dye Direct Yellow 8 (DY8) and bovine serum albumin (BSA) using techniques such as UV-Vis absorption, circular dichroism, FTIR, fluorescence, and time-resolved fluorescence. Azo dyes like DY8 exhibit carcinogenic properties and may cause cancer when they come into contact with biomolecules during intake; therefore, it is imperative to extensively explore their characteristics. Absorption studies were conducted to decipher the formation of the BSA-DY8 ground-state complex. To investigate the mechanism of quenching, temperature-dependent fluorescence quenching studies were performed, supported by time-resolved fluorescence analysis. The feasible mode of quenching for the BSA-DY8 system is non-radiative energy transfer. Toxicity studies were conducted using multiple spectroscopic techniques to anticipate and define the binding interaction between BSA and DY8. Docking, computer simulations, and molecular dynamics revealed a stable binding configuration with least fluctuations. Furthermore, we demonstrate the proliferative effect of the textile dye DY8 in mammalian HEK 293 cells, highlighting the need to develop non-carcinogenic dyes and improve the treatment of industrial effluents.