Construction of Frustrated Lewis Pairs for Efficient Artificial Enzyme

Abstract

Optimizing the binding sites of substrates for small molecules activation plays a crucial role in enzyme-like catalysts design. Herein, the frustrated Lewis pairs (FLPs) are successfully constructed through boron (B) doping into CoO_x (CoBO_x) with abundant oxygen vacancies (O_v). The O_v optimizes the valence of active sites, creates a coordinatively unsaturated state, and elongates the distance of Lewis pairs. The electron-deficient Lewis acid (LA) sites (Co) facilitate the adsorption and dissociation of O₂, and the electron-rich Lewis base (LB) sites (O) draw the positively charged TMB closer to Co sites and shorten the reaction distance, which synergistically improve the oxidase (OXD)-like activity. Besides, the increase of electron density induced by FLPs promotes the electrons transfer, intermediates stabilization, and decreases the energy barrier of the rate-determining step in adsorption and dissociation of O₂. Significantly, in a proof-of-concept application of colorimetric biosensing platform, the as-developed FLPs in CoBO_x demonstrate highly sensitive and selective detection capacity of dopamine (DA) targets. This work verifies the application possibility of activating small molecules through FLPs in enzyme-like catalysis.