WaveFlex Biosensor: MXene-Immobilized W-shaped Fiber-Based LSPR sensor for highly selective tyramine detection

Tyramine is generally produced via decarboxylation of tryptophan, and its long-term exposure can induce severe symptoms in humans like brain stroke and hypertensive crisis. It also served as an important factor to check the food quality, as its increased level is frequently found in rotten food products. Thus, more precise, practical, quick, and easy methods have been required for the detection of tyramine in various samples. In the present study, a localized surface plasmon resonance (LSPR) optical fiber-based, highly sensitive, and selective method for tyramine detection has been proposed. The fiber surface has been functionalized with MXene and gold nanoparticles to provide increased surface area for enzyme immobilization as well as enhance the performance of the sensor. The results showed that the developed sensor efficiently detects tyramine with high specificity due to the presence of the tyrosinase enzyme. Further studies revealed the stability, repeatability, and reusability of the proposed biosensor with a 6.96 µM detection limit and a sensitivity of 0.0385 nm/µM. As a result, the proposed optical fiber-based sensor has significant potential for application in the detection of the presence of tyramine in a wide variety of agricultural and food samples.