Probing the binding behavior and kinetics of silver nanoparticles with bovine serum albumin

Abstract

Nanomaterials have been utilized as multifunctional diagnostic and therapeutic agents. However, the effective application of nanomaterials is hampered by our limited understanding and control over their interactions with specific biological systems. Elucidating the binding mechanism and kinetic behavior of metal nanomaterials with proteins is significant, and herein we investigate the interaction of a model protein, bovine serum albumin (BSA), with silver nanoparticles (AgNPs) using fluorescence, synchronous fluorescence, ultraviolet (UV) absorption, Fourier transform infrared spectroscopy (FT-IR) and circular dichroism (CD) techniques in aqueous solutions. The experimental results indicated that the binding of AgNPs to BSA seems to be of a static quenching type with the formation of a ground state complex. With the determination of the binding constants and thermodynamic parameters, it is suggested that the binding process of AgNPs to the surface of BSA is spontaneous. Moreover, it was demonstrated that the main acting forces between the AgNPs and BSA may be hydrophobic and electrostatic interactions. At the same time, synchronous fluorescence, FT-IR and CD techniques were employed to analyze the conformational change of BSA in the presence of AgNPs. The results of kinetic studies reveal that the adsorption of BSA on the AgNP surface tends to have pseudo-second-order kinetic characteristics with an obvious hysteresis effect.