Reusable molecularly imprinted plasmon resonance fiber-optic sensor for berberine detection

The development of sensitive and reusable sensors for berberine hydrochloride (BH) detection remains a challenge. To address this, this paper proposes a simple, label-free, reusable, and stable optical fiber sensor using molecular imprinting polymer (MIP) for quantitative detection of berberine hydrochloride. Using BH as a template, sodium 4-styrene sulfonate (SSS) as a functional monomer, a BH molecular imprinting optical fiber sensor (BH-SSS@CS-MIP/OFS) based on surface plasmon resonance was successfully constructed. The sensor’s performance was meticulously characterized using spectral analysis, high-resolution scanning electron microscopy. The research results show that the sensor can significantly enhance the ability of recognizing BH compared to the unimprinted sensor and is not interfered with by other antibiotics. It achieves a wide detection range of 0.5–1000 μM, with a detection limit as low as 0.47 μM, and follows the Langmuir isotherm model. BH-SSS@CS-MIP/OFS can be desorbed by sodium hydroxide for multiple uses without changing its performance. The sensing response of the same sensor to a standard solution was measured over a period of 14 days (at 0, 7, and 14 days). The relative standard deviation (RSD) was 2.3 %. The prepared sensor was used to detect BH in water samples and found that the recovery rate ranged from 98 % to 108 %. After a series of tests, the novel BH molecular imprinting sensor has been proven to be an effective tool for monitoring BH. The unique advantages of MIP-based sensors, such as repeatability, simplicity, and reusability, make it a promising method for berberine hydrochloride detection and can be extended to detect other antibiotic molecules.