A fluorescence biosensor for tyrosinase activity analysis based on silicon-doped carbon quantum dots

Tyrosinase (TYR) plays a pivotal role in the biosynthesis of melanin, and its activity level holds critical implications for vitiligo, melanoma cancer, and food nutritional value. The sensitive determination of TYR activity is of great significance for both fundamental research and clinical investigations. In this work, we successfully synthesized silicon-doped carbon quantum dots (Si-CQDs) through a one-pot hydrothermal method with trans-aconitic acid as carbon source and N-[3-(Trimethoxysilyl)propyl]ethylenediamine as the dopant, exhibiting remarkable fluorescence quantum yield (QY) and photostability. Correspondingly, Si-CQDs were used as a probe to construct a sensitive, rapid, and user-friendly fluorescence method for TYR detection. The method relied on the oxidation of isoprenaline (ISO) by TYR, where Si-CQDs were employed as a highly efficient probe. The testing mechanism was the internal filtering effect (IFE) observed between Si-CQDs and the oxidative system of ISO and TYR. Under the optimized conditions, the fluorescence strategy exhibited a detection range of 0.05-2.0 U/mL for TYR with a limit of detection (LOD) of 0.041 U/mL. Furthermore, we successful demonstrated the accurate determination of TYR levels in human serum, showcasing the promising potential of this method in various practical scenarios.