Interaction of Gold Nanoparticle with Glycated Human Serum Albumin: Impact of Morphology and Different Surface Functionalization

A layer of proteins covers the nanoparticles by exposure to the nanoparticles in biological fluids. The phenomenon known as biocorona can alter the nanoparticle's specific purpose. Since the usage of nanoparticles in biological issues such as drug delivery, biosensor, and photothermal has increased, evaluating nanoparticles' interactions with biomolecules is necessary. Hydrophilic polymers form a layer of water molecules that reduces the interaction potential between nanoparticles and biomolecules. In this study, the effects of gold nanoparticle morphology (spheres and rods) and surface functionalization (PEG and GSH) on glycosylated serum albumin, a model protein in diabetic patients, its secondary structure and chemical stability using circular dimorphism technique were investigated.PEG-AuNPs exhibit a larger hydrodynamic radius than GSH-AuNPs due to their large hydrophilic tails. After interaction with the protein, the nanoparticles showed less interaction with the protein due to the formation of a layer of water around them that reduces the probability of interaction with proteins. The circular dichroism also exhibits that different modified nanoparticles do not significantly influence secondary structure. The presence of nanoparticles with hydrophiliccoatings, mainly polyethylene glycol with high water retention, reduce protein availability from urea in the long run and as a result will increase the 〖∆G〗_H2O value.