Selective determination of isoniazid using bentonite clay modified electrodes

Area of Science:

• Electrochemistry
• Materials Science
• Analytical Chemistry

Background:

• Development of sensitive and selective electrochemical sensors is crucial for pharmaceutical analysis.
• Immobilization of redox-active species onto electrode surfaces enhances sensor stability and performance.
• Iron complexes offer tunable redox properties for electrocatalytic applications.

Purpose of the Study:

• To develop a novel electrochemical sensor for the sensitive determination of isoniazid (IZ).
• To investigate the electrocatalytic oxidation of IZ using an immobilized iron complex.
• To evaluate the analytical applicability of the sensor for IZ determination in pharmaceutical products.

Main Methods:

• Ion-exchange immobilization of Fe(dmbpy)3(2+) onto a bentonite clay film coated glassy carbon electrode.
• Cyclic voltammetry (CV) for characterizing the immobilized complex and redox processes.
• Chronoamperometry and chronocoulometry for kinetic parameter determination and sensor response.
• Electrocatalysis mechanism elucidation (EC') for IZ oxidation.

Main Results:

• Stable and reproducible cyclic voltammetry characteristics of immobilized Fe(dmbpy)3(2+).
• Efficient electrocatalytic oxidation of isoniazid by the immobilized Fe(dmbpy)3(3+) complex.
• Linear relationship between anodic current and IZ concentration over a wide dynamic range (10.0 μM to 10.0 mM).
• Successful determination of IZ in a pharmaceutical product, demonstrating analytical suitability and interference discrimination.

Conclusions:

• The developed sensor provides a simple, cheap, and easy-to-fabricate platform for sensitive chronoamperometric determination of isoniazid.
• The EC' electrocatalysis mechanism facilitates sensitive IZ detection with excellent analytical performance.
• The sensor exhibits potential for practical application in pharmaceutical quality control.