Immobilization of Enzymes on Cyclodextrin-Anchored Dehiscent Mesoporous TiO2 for Efficient Photoenzymatic Hydroxylation

A three-in-one heterogeneous catalyst (UPO@dTiO(2)-CD) was fabricated by grafting cyclodextrins (CDs) on the dehiscent TiO2 (dTiO(2)) surface and subsequently immobilizing unspecific peroxygenase (rAaeUPO), which exhibited double enhanced electron/mass transfer in photo-enzymatic enantioselective hydroxylation of the C-H bond. The tunable anatase/rutile phase ratio and dehiscent mesoporous architectures of dTiO(2) and the electron donor feature and hydrophobic inner cavity of the CDs are independently responsible for accelerating both electron and mass transfer. The coordination of the photocatalytic and enzymatic steps was achieved by structural and compositional regulation. The optimized UPO@dTiO(2)-CD not only displayed high catalytic efficiency (turnover number and turnover frequency of rAaeUPO up to >65,000 and 91 min(-1), respectively) but also exhibited high stability and reusability.

Automated summary

A three-in-one heterogeneous catalyst (UPO@dTiO(2)-CD) was developed by grafting cyclodextrins (CDs) on the surface of dehiscent TiO2 (dTiO(2)) and immobilizing unspecific peroxygenase (rAaeUPO). The catalyst showed enhanced electron and mass transfer due to the unique properties of dTiO(2) and CDs. By coordinating the photocatalytic and enzymatic steps, the optimized UPO@dTiO(2)-CD exhibited high catalytic efficiency, stability, and reusability.