In this study, we construct a green and highperformance platform using Pickering emulsions for biphasic catalysis. The oil-in-water Pickering emulsions stabilized by the lignin/chitosan nanoparticles (Lig/Chi NPs) have great stability and alkali resistance, showing pH-responsive reversible emulsification and demulsification which can be recycled at least three times. The Pickering emulsion also has fluorescence and wide availability to different oil-to-water volume ratios, types of oil, storage times, temperatures, and ion concentrations. When this system is applied to the lipase-catalyzed reaction for the hydrolysis of p-nitrophenol palmitate, it will provide stable and large oil-water reaction interface areas, and the negatively charged lipase will enrich at the emulsion interface by electrostatic adsorption of the positively charged Lig/Chi NPs to achieve immobilization (lipase-Lig/Chi NPs). The reaction conversion rate can reach nearly 100% in 30 min, which is nearly three times higher than that of the conventional two-phase system. Moreover, the lipases in Pickering emulsion stabilized by Lig/Chi NPs exhibit great recyclability because of the protection of Lig/Chi NPs.

Inspired by the hierarchical chiral assembly of porphyrin-proteins in photosynthetic systems, the hierarchical self-assembly of porphyrin-amino acids/ peptides provides a novel strategy for constructing functional materials. How to artificially simulate...

Nanozymes are defined as mimic enzymes with both unique nanostructures and catalytic activity. Inspired by natural enzymes, herein, we reported a dual-functional nanozyme of Au/Cu hierarchically organized particles (Hops) with excellent polyphenol oxidase-like (PPO-like) and peroxidase-like (POD-like) activities, which could rapidly oxidize refractory toxic phenolic pollutants and serve as a sensitive tool to detect biologically energy-supplying substances. Au/Cu Hop nanozymes exhibited excellent catalytic activity and recyclability and were stable under extreme conditions. Notably, Au/Cu Hop nanozymes had higher substrate affinity and 6.37 times higher V max compared with natural laccase for hydroquinone oxidation reaction at the same mass concentration. Furthermore, the cascade reaction system was constructed based on the POD-like activity of Au/Cu Hops to detect glucose concentration with a low detection limit of 5 μmol L −1 . Significantly, we demonstrated the formation of dual-catalytic active sites by Cu-S clusters on the surface of Au/Cu Hops by the molecular dynamics simulations and revealed the mimic enzyme catalysis pathway by the density functional theory calculation. This work has important implications for the construction and application of dual-functional mimetic enzymes.