Development of a sensitive and inexpensive electrochemical sensor for indigotin using poly(valine) modified carbon...

Area of Science:

• Electrochemistry
• Materials Science
• Analytical Chemistry

Background:

• Indigotin (IGN) determination requires sensitive and selective electrochemical methods.
• Carbon paste electrodes (CPE) are versatile platforms for electrochemical sensing.
• Developing cost-effective and renewable sensors is crucial for environmental monitoring.

Purpose of the Study:

• To develop a straightforward, inexpensive, and renewable electrochemical sensor for indigotin (IGN) determination.
• To investigate the electrochemical performance of an electro-polymerized valine (VLN) stimulated carbon paste electrode (CPE) for IGN detection.
• To assess the analytical applicability of the developed sensor for IGN in real-world water samples.

Main Methods:

• Fabrication of poly(valine) modified carbon paste electrodes (P(VLN)MCPE).
• Electrochemical characterization using cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS).
• Scanning electron microscopy (SEM) for surface morphology analysis.
• Optimization of electrochemical parameters including pH and scan rate.
• Determination of indigotin (IGN) in phosphate buffer solution (PBS) and water samples.

Main Results:

• The P(VLN)MCPE exhibited enhanced sensitivity and electrocatalytic activity for indigotin (IGN) compared to bare CPE.
• The IGN oxidation-reduction reaction on P(VLN)MCPE was identified as an adsorption-controlled pathway.
• A wide linear range (0.2 to 5.0 μM) with a low limit of detection (LOD) of 0.0069 μM and limit of quantification (LOQ) of 0.023 μM was achieved.
• The sensor demonstrated good reproducibility, stability, and repeatability.
• Successful application for indigotin (IGN) detection in water samples with impressive recovery rates.

Conclusions:

• The electro-polymerized valine modified carbon paste electrode (P(VLN)MCPE) is a highly effective sensor for indigotin (IGN) determination.
• The developed sensor offers a promising, cost-effective, and renewable solution for accurate IGN analysis.
• The sensor's performance in real water samples highlights its practical applicability in environmental monitoring.