One-pot synthesis of stable antioxidant metal-ornamented polyphenol supramolecular assemblies for material engineering

Abstract Natural polyphenols (NPPs) are of widespread interest in material engineering; however, only a small fraction of NPPs have been utilized in biomedical applications because of their poor solubility and instability in aqueous conditions. Herein, we report a family of metal-ornamented polyphenol supramolecular (MOPS) assemblies that are highly stable in aqueous solutions for over 6 months. In this one-pot, green synthesis method, metal ions are reduced in water by NPPs to form NPP-capped metal nanoclusters, which then assemble with more NPP molecules to form stable hydrophilic MOPS assemblies. This strategy is generally applicable to a range of NPPs (25 polyphenols tested) regardless of their original water solubility. The resulting stable MOPS assemblies, integrating attributes of both NPPs and metal nanoclusters, possess much stronger antioxidant capabilities than the NPPs, notably a multiplied capacity in superoxide-free radical scavenging capacity. MOPS assemblies can be further engineered, based on polyphenol chemistry, into various functional materials with potential for a wide range of antioxidant applications.