Highly fluorescent gold nanoclusters stabilized by food proteins: From preparation to application in detection of food contaminants and bioactive nutrients

Applications of nanotechnology in food have rapidly increased in the past decades. Ultra-small gold nanoclusters (Au NCs), composed of several to roughly a hundred atoms, represent a kind of novel nanomaterials. The Au NCs directed by food proteins have drawn considerable research attention due to their environment-friendly preparation, strong fluorescence, excellent photo-stability, and favorable biocompatibility. These interesting protein-Au hybrids have opened up a new area at the nano-bio-food interface, not only did they provide the missing link between single metal atoms and plasmonic metal nanoparticles, but also developed the hybrid system between biomacromolecule and inorganic ions. In this review, we highlighted the synthesis strategies and optical properties of the Au NCs stabilized by typical food proteins as well as their applications in detection of food contaminants or bioactive nutrients. In addition, we discussed current challenges and future development in food proteins-directed gold nanoclusters for size-controlled synthesis and multifunctional applications.