Green Tea Makes Polyphenol Nanoparticles with Radical-Scavenging Activities.

The constant demand for functional nanomaterials from natural biomass polymers usually requires new "green" synthetic strategies without using any foreign additives. Here, the green fabrication of a series of polyphenol nanoparticles (PNs) only from green tea extraction compounds is reported (i.e., tea polyphenols and theophylline). It is found that the nanoparticle formation process involves covalent copolymerization of monomers, as well as noncovalent self-assembly pathways. Additionally, the resulting PNs exhibit better free-radical scavenging activities compared with similar-sized, polydopamine-based synthetic melanin nanoparticles. This class of biomass-based functional nanoparticles is promising as green and effective antioxidant agents in general.