Enzyme–Polymer Conjugates as Robust Pickering Interfacial Biocatalysts for Efficient Biotransformations and One‐Pot Cascade Reactions.

Despite the rapid development of Pickering interfacial catalysis (PIC) at liquid–liquid interfaces with chemocatalysts, the use of unstable biocatalysts at emulsion interfaces remains a technical challenge. Herein, we present a Pickering interfacial biocatalysis (PIB) platform based on robust and recyclable enzyme–polymer conjugates that act as both catalytic sites and stabilizers at the interface of Pickering emulsions. The conjugates were prepared by growing poly(N‐isopropylacrylamide) on a fragile enzyme, benzaldehyde lyase, under physiological conditions. The mild in situ conjugation process preserved the enzyme structure, and the conjugates were used to emulsify a water–organic two‐phase system into a stable Pickering emulsion, leading to a significantly larger interfacial area and a 270‐fold improvement in catalytic performance as compared to the unemulsified two‐phase system. The PIB system could be reused multiple times. Conjugates of other enzymes were also fabricated and applied for cascade reactions. Gentle giants: Enzyme–polymer conjugates were created that acted simultaneously as catalytic sites and stabilizers at the interface of Pickering emulsions to enable effective Pickering interfacial biocatalysis (PIB; see picture, ATRP=atom‐transfer radical polymerization). The extraordinarily large contact area of the system contributed to the efficiency of the biotransformations in both single‐ and multiple‐step reactions. [ABSTRACT FROM AUTHOR]