Ring core optical fiber SPR sensor for high-sensitivity detection of isoquercitrin

The miniaturization development of traditional Chinese medicine active ingredient sensors still faces difficulties such as low sensitivity and inconvenient detection. This paper proposed a ring core optical fiber surface plasmon resonance (SPR) traditional Chinese medicine active ingredient sensor. The ring core with a ring width of 7 μm effectively reduces the number of transmission modes of light, and the bending degree of the core is controlled by fiber microfabrication technology to reduce the SPR incident angle and greatly improve the sensitivity of the sensor, reaching 5164 nm/RIU. Furthermore, taking the active ingredient isoquercitrin in traditional Chinese medicine as an example, its target Protein Tyrosine Phosphatase-1B (PTP1B) was immobilized on the surface of a gold membrane, achieving specific detection with a detection limit as low as 1.5 μg/L, which is comparable to high-performance liquid chromatography. The ring core fiber SPR sensor proposed in this article has the advantages of high sensitivity and short detection time, providing new ideas for the development of miniaturized, highly sensitive, and portable Chinese medicine active ingredient detection equipment.