Interfacial and structural characterization of BSA-coated silver nanoparticles

Silver nanoparticles (AgNPs) have attracted considerable attention due to their unique physicochemical properties and potential applications in biomedicine, including antimicrobial activity and targeted drug delivery. The formation of a protein corona is a key determinant of nanoparticle behavior in biological environments, influencing stability, biodistribution, and cellular interactions. In this work, we investigated the interaction between AgNPs and bovine serum albumin (BSA) as a model protein, focusing on the physicochemical changes induced by the corona formation.

AgNPs were synthesized via a chemical reduction method and subsequently incubated with BSA under controlled conditions. Surface tension measurements were performed to evaluate changes in the interfacial properties of the nanoparticle–protein system, providing insight into adsorption processes at the nanoscale. Transmission electron microscopy (TEM) was employed to characterize particle morphology, size distribution, and the presence of protein layers on the nanoparticle surface.

Surface tension analysis revealed a concentration-dependent decrease in interfacial tension upon BSA addition, indicating effective adsorption and surface modification of AgNPs. TEM images confirmed the formation of well-dispersed nanoparticles with spherical morphology and the presence of a thin, uniform organic coating consistent with a protein corona. The average particle size increased slightly after BSA adsorption, supporting the formation of a stable protein layer.

These findings demonstrate that BSA effectively interacts with AgNPs, inducing significant alterations in surface properties and nanoparticle morphology. The combination of surface tension measurements and TEM analysis provided complementary information, enabling a deeper understanding of the physicochemical effects of protein corona formation. Such insights are crucial for optimizing the design of nanoparticle-based systems for biomedical applications, where precise control over protein–nanoparticle interactions is essential to achieve predictable biological responses.