Upconversion-luminescent optical fiber probe for in situ tyrosinase monitoring

Tyrosinase (TYR) is related to a variety of skin diseases, melanoma and Parkinson's disease, and it is essential for the quantitative detection of TYR. Although the traditional TYR sensors in solution have extremely high sensitivity, and it is expected to develop a biosensor for point of care (POC) detection due to its poor portability, nanoparticle aggregation, reusability, and complexity of use. Here, we report a simple and compact interrogation setup of an optical fiber sensor that facilitates signal transmission and can identify and quantify TYR. The sensor consists of multimode optical fibers (MOF) modified by up-conversion nanoparticles (UCNPs) based on chemical bonds, and the photoconductive MOF can both excite UCNPs and collect the upconversion fluorescence of UCNPs. TYR is detected based on photo-induced electron transfer (PET) between UCNPs and dopaquinone (DQ). The fiber optic sensor has an optical reading, a linear response of up to 0.6 U mL(-1), and a detection limit as low as 0.028 U mL(-1). Our optical microsensor has great potential to be used as a portable and in situ detection probe to monitor TYR.

Automated summary

The study introduces a simple and compact fiber optic sensor for the detection and quantification of TYR. The sensor has high sensitivity and portability, making it a convenient and practical point of care detection method.