In this work, we studied the formation and properties of composite films coassembled by cellulose nanocrystals (CNCs) and bovine serum albumin-stabilized gold nanoclusters (BSA-AuNCs). The influences of the BSA-AuNC concentration on the structure and optical properties of CNC-based composite films were further studied. It was found that the composite film retained the chiral nematic structure and optical activity. The self-assembled CNC and BSA-AuNC helical superstructures can produce strong, left-handed, circularly polarized luminescence with dissymmetry factors up to 0.287. Meanwhile, the third component, polyethylene glycol, was introduced without affecting the structural color and fluorescence characteristics of the composite film to enhance the flexibility of the film. The simplicity of the film preparation, the abundance of CNCs, and the flexibility and stability of the composite films pave the way for the production of functional materials with integrated functions.

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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.