Paper-Based Electrochemical Detection of Chlorate.

Area of Science:

• Electrochemistry
• Analytical Chemistry
• Materials Science

Background:

• Chlorate (ClO3-) is an environmental contaminant requiring sensitive detection methods.
• Existing methods for chlorate determination can be complex and time-consuming.
• Development of portable and cost-effective sensors is crucial for environmental monitoring.

Purpose of the Study:

• To develop and validate a paper-based electrochemical probe for the quantitative determination of chlorate.
• To investigate the performance of a vanadium-containing polyoxometalate anion, [PMo11VO40]5-, for chlorate sensing.
• To assess the stability and reproducibility of the developed sensor system.

Main Methods:

• Fabrication of a paper-based probe using screen-printed carbon electrodes impregnated with [PMo11VO40]5-.
• Electrochemical characterization using cyclic voltammetry (CV) and chronocoulometry in a buffered solution (pH 2.5).
• Analysis of chlorate in soil samples to evaluate practical applicability.

Main Results:

• Linear current response observed via CV for chlorate concentrations between 0.156 and 1.25 mg/mL, with a detection limit of 0.083 mg/mL.
• Reproducible sensor performance maintained with probes stored for up to 8 months under ambient conditions.
• Chronocoulometry yielded linear responses for charge and slope vs. time, with detection limits as low as 0.15 mg/mL.
• Successful recovery measurements in soil samples indicate practical utility.

Conclusions:

• The paper-based [PMo11VO40]5- probe offers a sensitive, reproducible, and stable platform for electrochemical chlorate determination.
• The developed sensor demonstrates potential for on-site and cost-effective monitoring of chlorate in environmental samples.
• Further optimization could enhance sensitivity and expand the application range for this sensing technology.