Gold nanoparticles (GNP) are a platform of interest with a broad range of applications in curative and preventive medicine (e.g.: cancer: tumor active or passive targeting, vaccine: antigen carrier). The system allows the presentation in high quantity of virtually any type of organic molecule on the surface of a gold core. The multivalent presentation of ligands, such as carbohydrates or proteins, can trigger a cluster effect, which allows to overcome the low affinity of the individual ligands towards their receptors.