Nanoplatforms with donor-acceptor Stenhouse adduct molecular switch for enzymatic reactions remotely controlled with near-infrared light

Enzymes have been widely used in biomedical applications owing to their excellent biocatalysis functions. However, the precise control of enzymatic reactions remains a challenge in vivo. Here, a nanoplatform functionalized with upconversion nanoparticles (UCNPs) as the core and a donor-acceptor Stenhouse adduct as a molecular switch (MS) was designed for near-infrared (NIR)-controlled enzymatic reactions. Under NIR irradiation, the UCNPs could emit bright green light to isomerize the MS and then transform the permeability of the MS-gated polymer layer, allowing small molecules to penetrate the polymer layer. Consequently, the contact between the enzyme and substrate could be regulated to control the enzymatic reaction remotely. As the photoisomerism of MS is reversible and the enzyme activity is not changed, the enzyme reactor based on this nanoplatform is also reversible, which can achieve precise temporal and spatial control of the enzyme reaction. Glucose oxidase (GOX), lactate oxidase (LOX), urate oxidase (UOX), and luciferase were used to assess the controllability of the enzymatic reactions. Both the substrates in and out of the nanoplatform were satisfactorily controlled, indicating that the gated nanoplatform equipped with valve-like characteristics could realize remotely controlled enzymatic reactions upon NIR irradiation.