Sensitive Voltammetric Sensor for Tryptophan Detection by Using Polyvinylpyrrolidone Functionalized Graphene/GCE

Area of Science:

• Electrochemistry
• Materials Science
• Analytical Chemistry

Background:

• Tryptophan (Trp) is a crucial amino acid with significant biological roles.
• Accurate and sensitive detection of Trp is essential for various applications, including clinical diagnostics and pharmaceutical analysis.
• Existing methods for Trp detection may have limitations in sensitivity, selectivity, or cost-effectiveness.

Purpose of the Study:

• To develop a novel electrochemical sensor for the sensitive and selective detection of tryptophan.
• To investigate the electrochemical behavior of tryptophan at a modified electrode.
• To validate the sensor's performance for detecting tryptophan in complex matrices.

Main Methods:

• Fabrication of a glassy carbon electrode (GCE) modified with polyvinylpyrrolidone-functionalized graphene (PVP-GR).
• Electrochemical characterization of the modified electrode using cyclic voltammetry and differential pulse voltammetry.
• Optimization of experimental parameters, including pH, buffer concentration, and potential scan rate.
• Determination of tryptophan concentration using the optimized electrochemical method.

Main Results:

• The PVP-GR/GCE exhibited a significantly enhanced oxidation peak current for tryptophan compared to bare GCE and other modified electrodes.
• The electrochemical oxidation mechanism of tryptophan on the PVP-GR/GCE was elucidated.
• A wide linear range for tryptophan detection (0.06 µM–100.0 µM) with a low limit of detection (0.01 µM) was achieved.
• The modified electrode demonstrated excellent repeatability, stability, and selectivity.

Conclusions:

• The developed PVP-GR/GCE provides a highly sensitive and selective platform for electrochemical tryptophan detection.
• The sensor shows great potential for the practical application in the analysis of tryptophan in pharmaceutical and biological samples.
• This work contributes to the advancement of electrochemical sensing technologies for biomolecule analysis.