Block copolymer nanoparticles-based fluorescent sensor for ultrasensitive detection of tyrosinase activity and inhibitor

It is of great value to develop a simple, rapid, label-free and sensitive strategy for tyrosinase activity detection and corresponding inhibitor screening in both biomedical diagnosis and cosmetic industry. However, many recently reported fluorescent assays may suffer from instability to light irradiation, poor water solubility, and complex modification. Herein, a novel fluorescent biosensor strategy has been developed capable of sensitive, label-free and rapid screening of tyrosinase activity as well as corresponding inhibitors based on fluorescent block copolymer nanoparticles (BCNs). The reported BCNs were prepared by coprecipitation assay using the mixture of amphiphilic block copolymer and fluorescent conjugated polymer, which show many advantages including high brightness, excellent photostability and biocompatibility, enabling the biosensor with high sensitivity and good reproducibility in a single-step operation. The reported assay exhibited high sensitivity and selectivity with a detection limit of 1.5 ng/mL for tyrosinase (TRY) activity detection and hold potential in its inhibitor screening. The satisfying recoveries offered great potential for complicated sample analysis. Hence, this reported assay may provide a novel platform for biosensor development.