Investigation on the interaction between Ag+ and bovine hemoglobin using spectroscopic methods

Silver ions (Ag+) can be released by silver nanoparticles (AgNPs) which are widely used in diverse fields. Ag+ can exist inside cells to produce cytotoxicity. This report uses spectroscopic methods to reveal the interactions between Ag+ and bovine hemoglobin (BHb). The results of the quenching rate constant (K-q) and the fluorescence lifetime detection showed that the quenching mechanism of BHb by Ag+ was static. Thermodynamic investigations indicated that Ag+ can interact with BHb with one binding site to form complex mainly through van der Waals interactions and hydrogen bonds. The UV-vis absorption and synchronous fluorescence spectra showed that Ag+ changed the conformation of BHb, which may affect protein functions. This research is favorable for understanding the molecular toxic mechanism of Ag+ in vivo.