Extremely concentrated silver nanoparticles stabilized in aqueous solution by Bovine Serum Albumin (BSA)

Abstract

Silver nanoparticle is a widely used nano metal material in medical, environmental, and material science. For certain research applications, extremely high concentrations of silver nanoparticle with biologically friendly capping reagents are required. In our study, the Bovine Serum Albumin (BSA) is used as the stabilizing reagent for synthesis of silver nanoparticles (Ag-BSA NPs) in aqueous solution, instead of the typical thiol capping agents and unfriendly organic polymers. The optimized preparation formulation of AgNO3:BSA:NaBH4 is at the weight ratio of 1:3.2:0.22, and at least 20g of BSA (4 g Ag NPs +20.0g BSA in one liter volume) is needed to stabilize 4g/L pure silver metal nanoparticle in aqueous solution. The BSA capped silver nanoparticles are extremely stabilized and concentrated in aqueous solution without any aggregation and can even be isolated and stored in solid state. The as-prepared Ag-BSA NPs was fully characterized both in solution and in solid state (UV–Vis, DLS, XRD, SEM (e.g. EDS and EA mapping) and TEM). Our findings can be extended to a wide range of applications of silver nanoparticles in biomedicine and environmental science.