A Host-Guest Approach to Engineering Oxidase-Mimetic Assembly with Substrate Selectivity and Dynamic Catalysis

Area of Science:

• Supramolecular chemistry
• Biomimetic catalysis
• Materials science

Background:

• Designing synthetic materials that mimic natural enzymes is a key challenge in biomimicry.
• Enzymes exhibit high selectivity and dynamic responsiveness, properties difficult to replicate in artificial systems.

Purpose of the Study:

• To create a supramolecular material that mimics copper-dependent oxidase activity with substrate selectivity and dynamic responsiveness.
• To introduce controllable catalytic properties into enzyme-mimetic materials.

Main Methods:

• Anchoring gamma-cyclodextrin to a fluorene-modified Lys/Cu2+ assembly.
• Investigating binding affinities using 1H NMR, isothermal titration calorimetry (ITC), and theoretical simulations.
• Assessing substrate oxidation and catalytic activity modulation.

Main Results:

• The gamma-cyclodextrin-based assembly demonstrated size-selective oxidation of aromatic substrates, favoring biphenyls.
• The material showed enhanced catalytic activity compared to native oxidase and lacked selectivity with alpha- and beta-cyclodextrins.
• Catalytic activity was dynamically tuned by adding alpha-cyclodextrin or through light irradiation.

Conclusions:

• The developed supramolecular material effectively mimics enzyme function with tunable selectivity and responsiveness.
• This strategy provides a new pathway for designing advanced biomimetic catalysts with tailored active sites.