A turn-on fluorescence assay of tyrosinase activity based on an enzyme-triggered hydroxylation of phenol for conformation of silicon nanoparticles.

Evolution of fluorometric sensing methods has brought an enormous opportunity and exhibited novel potentials for enzymatic activities determination. Herein, we have established an accurate and straightforward fluorescent sensing approach for tyrosinase (TYR) activity based on the formation of fluorescent silicon nanoparticles (Si NPs). Influenced by TYR-induced hydroxylation of phenol into catechol, and an easy reaction between catechol and 3(2-aminoethylamino) propyl (dimethoxymethylsilane) (AEAPDMMS) to generate Si NPs, we have designed a label-free fluorescence turn-on probe for TYR activity measurement. After optimization of all reaction parameters, the proposed approach could selectively determine TYR activity in the linearity range of 0.08–9 U mL−1 with the limit of detection (LOD) of 0.03 U mL−1. The practicability of the method in real sample was assessed by measuring TYR activity in human serum sample with successful results. In addition, Si NPs were wonderfully acceptable for Hela and SiHa cells imaging by virtue of their tolerable cytotoxicity and impressive biocompatibility. Therefore, the designed fluorescent biosensor exhibited a potential and widespread implementation in clinical diagnoses assays. • Silicon nanoparticles based-fluorescence probe was used to determine Tyrosinase. • Tyrosinase could easily make hydroxylation of phenol into catechol. • No further surface modification or purification of silicon nanoparticles was applied. • The designed approach exhibited high performance for Hela and SiHa cell imaging capability. • The designed method was used to determine Tyrosinase in human serum samples. [ABSTRACT FROM AUTHOR]