The application of nanotechnology to medicine has gained wide attention in numerous important scientific fields, ranging from diagnostic imaging with contrast agents to targeted drug delivery and photodynamic therapy.However, upon contact with biological fluid, these GNPs are coated with a layer/corona of proteins that leads to unexpected changes in cellular uptake, cellular interactions, biodistribution, and nanotoxicity. Therefore, detailed knowledge of the protein corona is of importance for the designation and development of nanoparticles with high targeting effect.