Development of WS₂-QDs/MoS₂-NSs-Based WaveFlex Biosensor for Tyramine Detection in Real Food Samples

Tyramine, a vasoactive amine with sympathomimetic properties, is commonly found in various foods. Elevated levels of tyramine in the blood can lead to adverse reactions like migraines and high blood pressure, underscoring the importance of detecting its content in food. This study introduces a WaveFlex biosensor utilizing the optical fiber-based localized surface plasmon resonance (LSPR) sensing principle to detect tyramine levels efficiently and accurately in different samples. The probe surface was covered with gold nanoparticles (AuNPs) to stimulate the LSPR effect, and then molybdenum disulfide nanosheets (MoS 2 -NSs) and tungsten disulfide quantum dots (WS 2 -QDs) were sequentially aligned on the probe surface. It enhanced the LSPR effect and at the same time provided more contact sites for tyrosinase enzyme functionalization, and significantly improved the sensor's sensitivity in detecting tyramine. Experimental findings reveal a detection limit of 2.80 μM and a sensitivity of 0.01122 nm/μM for the biosensor. The probe's reproducibility, reusability, stability, selectivity, as well as its performance with real samples and varying pH levels were evaluated. The results highlight the promising application potential and wide-ranging development opportunities for this WaveFlex biosensor in detecting tyramine levels across diverse samples.