Formation of size and shape tunable gold nanoparticles in solution by bio-assisted synthesis with bovine serum albumin in native and denaturated state

We have successfully controlled the size and shape of gold nanoparticles (GNPs) through a one-step bio-assisted procedure by using bovine serum albumin (BSA) protein as both reducing and stabilizing agent. We found that the growing process of GNPs can be directly manipulated by simply controlling the BSA concentration in solution and the reaction temperature. The GNPs formation was followed both experimentally by UV–vis–NIR spectroscopy and transmission electron microscopy (TEM) and theoretically by finite difference time domain (FDTD) simulations. The surface plasmon resonance of as-prepared GNPs suits the needs of many biological applications.

► We investigate the ability of bovine serum albumin to synthesize gold nanoparticles.
► Bovine serum albumin protein acts as both reducing and stabilizing agent.
► The size of nanoparticles can be varied by adjusting the protein concentration.
► The shape of nanoparticles can be tuned by reaction temperature.
► The obtained nanoparticles can be used as bio-substrates for SERS applications.