Investigation of silver nanoparticles and plasma protein association using flow field-flow fractionation coupled with inductively coupled plasma mass spectrometry (FlFFF-ICP-MS)

Flow field-flow fractionation (FlFFF) with on-line inductively coupled plasma mass spectrometer (ICP-MS) was employed to investigate the association between protein and silver nanoparticles (AgNPs). In this work, bovine serum albumin (BSA), globulin, and fibrinogen were the model proteins studied. AgNPs were prepared by the reduction of silver nitrate using tannic acid as reducing and stabilizing agent. Various sizes (2.6, 10, and 26 nm) were obtained depending on the pH condition during particle preparation. The apparent association constants between BSA and AgNPs of various sizes were determined. Then, various concentrations of 2.6 nm AgNPs were incubated with plasma proteins, i.e., albumin (2.6 × 10^-1 M); globulin (3.1 × 10^-2 M); and fibrinogen (2.9 × 10^-3 M) at 37 °C for investigation of protein-AgNPs association. Factors influencing protein-AgNPs association were investigated, including the effect of incubation time and effect of AgNPs concentration. Association between protein and AgNPs increased as the incubation time and concentration of AgNPs increased. Further, the binding stoichiometry between BSA and AgNPs was determined to be approximately 1:5 × 10^-7.