Host–guest chemistry on living cells enabling recyclable photobiocatalytic cascade†

Abstract

Combining chemical and whole-cell catalysts enables sustainable chemoenzymatic cascade reactions. However, their traditional combination faces challenges in catalyst recycling and maintaining cell viability. Here, we introduce a supramolecular host–guest strategy that efficiently attaches photocatalysts to bacterial cells, facilitating recyclable photobiocatalysis. This method involves attaching a cationic polyethylenimine (PEI) polymer, functionalized with β-cyclodextrin (β-CD), to E. coli cells. The polymer attachment is biocompatible and protective, safeguarding the cells from harsh conditions such as UV radiation and organic solvents, without causing cell death. Additionally, the presence of β-CD imparts a plug-and-play capability to the cells, enabling the straightforward integration of guest photocatalysts – specifically anthraquinone – onto the cell surface through host–guest interactions. This effective combination of cellular and chemical catalysts promotes efficient photobiocatalytic cascades and supports the photocatalyst's recycling and reuse. This supramolecular system thus represents a promising platform for advancing photobiocatalysis in cascade synthesis.