Abstract
Silver nanoparticle (AgNP) is widely used in our daily life, including consumer goods, clothes, electronics, and also many emerging technology in biomedical applications (e.g., carriers, sensors). In this study, we investigated the colloidal stability of AgNPs under acidic and/or highly ionic environments, and the subsequent interaction with the plasma protein to their colloidal stability. Electrospray-differential mobility analysis was used to characterize the particle size distributions and the number concentrations of AgNPs. Transmission electron microscopy was employed orthogonally to provide visualization of AgNPs. For unconjugated AgNPs, the particles size was increased by aggregation as increasing the acidity and/or ionic strength, accompanied with a change of morphology due to acid-induced interfacial dissolution, but aggregation and dissolution were both shown to be insignificant for bovine serum albumin-functionalized AgNPs. This work provides a generic method to analyze colloidal stability of surface functionalized AgNPs over various formulation chemistry and environment conditions (e.g., cell culture media and natural water).