MoS₂/S@g-CN Composite Electrode for L-Tryptophan Sensing

Area of Science:

• Electrochemistry
• Materials Science
• Analytical Chemistry

Background:

• L-tryptophan (L-TRP) is an essential amino acid crucial for human nitrogen balance.
• Accurate quantification of L-TRP is vital for nutritional and health monitoring.
• Existing detection methods may lack sensitivity, stability, or selectivity.

Purpose of the Study:

• To develop and characterize a novel electrochemical sensor for sensitive L-tryptophan detection.
• To synthesize and analyze a molybdenum disulfide/sulfur-g-carbon nitride (MoS2/S@g-CN) composite.
• To evaluate the performance of the modified electrode for L-TRP quantification.

Main Methods:

• Hydrothermal synthesis of the MoS2/S@g-CN composite.
• Characterization using PXRD, SEM, XPS, and EDX.
• Fabrication of a MoS2/S@g-CN modified glassy carbon electrode (GC).
• Electrochemical detection of L-TRP using cyclic voltammetry (CV) and differential pulse voltammetry (DPV).

Main Results:

• The MoS2/S@g-CN composite exhibited porous ball structures with MoS2 decorated on S@g-CN.
• XPS confirmed the presence of Mo, S, O, C, and N elements.
• The modified electrode achieved a low limit of detection (LoD) of 0.03 µM for L-TRP.
• High sensitivity (1.74 µA/µMcm²), stability, repeatability, and selectivity were demonstrated.

Conclusions:

• The developed MoS2/S@g-CN/GC electrode is a highly effective platform for electrochemical L-TRP detection.
• The sensor offers significant advantages in terms of sensitivity, stability, and selectivity.
• This approach provides a promising tool for quantifying essential amino acids in biological samples.