Development of Novel MoS ₂ /Carbon‐Based Electrochemical Sensor for Ultra‐Trace Level Detection of Tryptophan in Real Samples

Abstract A novel voltammetric electrochemical sensor was designed for the detection of tryptophan (Trp), an essential amino acid and potential biomarker for various health conditions. The MoS 2 : MWCNT: Graphite @GCE electrode was fabricated and characterized using XRD, SEM‐EDS, FTIR, and AFM techniques to confirm its structure and surface morphology. The electrochemical performance was evaluated through EIS, while CV and SWV were employed for Trp determination. Optimal results were achieved at pH 7.0, showing an oxidation peak within 0.3–1.3 V, indicating a diffusion‐controlled electrode process. Using SWV, the limit of detection (LOD) and limit of quantification (LOQ) were found to be 34.50 nM and 114.90 nM, respectively, showing improved sensitivity over previously reported methods. The developed sensor was successfully applied for the determination of Trp in biological and water samples, highlighting its accuracy, stability, and potential for clinical and environmental applications.