Ultraviolet/Visible Light-Responsive Pickering Interfacial Biocatalysis: Efficient and Robust Platform for Bioconversions

Stimuli-responsive Pickering interfacial biocatalysis (PIB) platforms are highly desirable due to their convenient product extraction and catalyst recovery. Light-responsive PIB stabilized by immobilized biocatalyst particles, which serve as both emulsifiers and catalysts, have not attracted enough attention. Herein, a novel and effective ultraviolet/visible light-responsive PIB system is proposed to facilitate reversible emulsification/demulsification. The modified hollow mesoporous silica nanospheres (HMSS-N) with photochromic spiropyran (SP-COOH) were utilized as a light-responsive emulsifier and carrier of lipase CL (CL@HMSS-SP). The light-responsive performance and catalytic performance of the PIB system were also studied in detail. As a result, the O/W emulsion demulsification or emulsification could be easily accomplished by inducing ultraviolet or visible light to change the surface wettability of the smart emulsifiers. The system exhibited the highest catalytic activity in the model esterification reaction between n-hexanol acid and 1-hexanol that has been reported so far (a catalytic efficiency value of 80.9 mmol g–1 h–1), which is a 12.6-fold enhancement compared with the conventional free enzyme one-phase system. The robust system maintained high catalytic activity even after 10 cycles, averaging 148.2 g of product g–1 biocatalyst. Thus, the ultraviolet/visible light-responsive PIB gives insights into the biocatalytic synthesis of flavor esters with high efficiency and stable reusability and shows great potential for cleaner production in the future.