Analytical performance of poly(L-cysteine) modified pencil graphite electrode for dapsone detection

Area of Science:

• Electrochemistry
• Analytical Chemistry
• Materials Science

Background:

• Dapsone (DP) is an important antimicrobial drug.
• Accurate quantification of DP is crucial for therapeutic monitoring and quality control.
• Existing analytical methods may lack sensitivity, selectivity, or cost-effectiveness.

Purpose of the Study:

• To develop and optimize a novel electroanalytical method for Dapsone determination.
• To investigate the electrochemical behavior of Dapsone at a modified electrode.
• To assess the method's applicability in real-world samples.

Main Methods:

• Electrochemical analysis using cyclic voltammetry (CV) and differential pulse voltammetry (DPV).
• Modification of a pencil graphite electrode (PGE) with poly-L-cysteine (poly-L-Cys).
• Optimization of experimental parameters including scan rate, DP concentration, and pH.

Main Results:

• The poly-L-Cys/PGE demonstrated efficient Dapsone detection, primarily based on adsorption.
• A linear relationship was observed between DPV anodic peak current and DP concentration (1.0 × 10⁻⁶ to 12.0 × 10⁻⁶ M).
• A low limit of detection (LOD) of 5.37 × 10⁻⁷ M was achieved with high sensitivity, selectivity, and stability.

Conclusions:

• The developed electroanalytical method offers a reliable and cost-effective approach for Dapsone quantification.
• The method was successfully validated for determining DP in pharmaceutical tablets and urine samples.
• This technique presents a viable alternative for routine Dapsone analysis in clinical and quality control settings.