Design and Fabrication of Tryptophan Sensor Using Voltammetric Method

Area of Science:

• Electrochemistry
• Materials Science
• Analytical Chemistry

Background:

• L-tryptophan is a vital amino acid, precursor to melatonin and serotonin, requiring regulated levels in humans and animals.
• Existing methods for L-tryptophan detection lack cost-effectiveness, simplicity, sensitivity, or selectivity.
• Developing an efficient L-tryptophan sensor is crucial for metabolic monitoring and health diagnostics.

Purpose of the Study:

• To fabricate and characterize a novel electrochemical sensor for L-tryptophan detection.
• To evaluate the sensing performance of a nickel-doped tungsten oxide ceramic-modified electrode (Ni-WO₃/GC).
• To establish a cost-effective, sensitive, and selective method for L-tryptophan quantification.

Main Methods:

• Synthesis of nickel-doped tungsten oxide (Ni-WO₃) ceramic using simple strategies.
• Characterization of Ni-WO₃ using powder X-ray diffraction, SEM, EDX, and XPS.
• Modification of a glassy carbon electrode (GC) with Ni-WO₃ and electrochemical analysis using cyclic voltammetry and differential pulse voltammetry.

Main Results:

• The synthesized Ni-WO₃ was successfully characterized, confirming its material properties.
• The Ni-WO₃/GC electrode demonstrated excellent sensitivity with a limit of detection of 0.4 µM for L-tryptophan.
• The sensor exhibited high selectivity, good reproducibility, repeatability, stability, and storage stability.

Conclusions:

• A novel Ni-WO₃/GC electrochemical sensor for L-tryptophan detection has been successfully fabricated.
• This sensor offers a cost-effective, simple, sensitive, and selective approach for L-tryptophan monitoring.
• This represents the first report on the application of Ni-WO₃/GC for L-tryptophan sensing.