Highly discriminative fluorometric sensor based on luminescent covalent organic nanospheres for tyrosinase activity monitoring and inhibitor screening

Abstract

Currently, covalent organic polymers (COPs)-based sensors have prevailingly been limited to determination of simple metal ions as well as organic small molecules. Covalent organic nanospheres (CONs) are a new type of very recently emerging COPs with unique properties and intriguing aesthetic architectures that hold tremendous potentiality in biosensing field. Thus, it is very important to explore new CONs-based sensors for the determination of biomarkers. Herein, we present a new luminescent CONs-based biosensor strategy for convenient, rapid, label-free tyrosinase (TYR) activity determination and its inhibitor screening. This approach depends on the TYR-mediated in situ growth of a melanin-like coating on the surface of CONs, which leads to an obviously fluorescence quenching of the CONs. This strategy is proved to provide superior sensitivity, and the detection limit is calculated to be as low as 0.0015 μg/mL. In addition, our constructed sensor exhibits high discrimination and can also be used for the determination of the TYR activity in complex biological samples and TYR inhibitor screening, which might provide a potential candidate for clinical diagnostics and biomedical research for TYR-related diseases.