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A new, improved sensor for ascorbate determination at copper hexacyanoferrate modified carbon film electrodes
Rasa Pauliukaite1, Mariana Emilia Ghica, Christopher M A Brett
1Departamento de Quimica, Universidade de Coimbra, 3004-535 Coimbra, Portugal.
Analytical and Bioanalytical Chemistry
|February 11, 2005
Summary
A novel copper hexacyanoferrate sensor offers a low-cost, sensitive method for determining ascorbate (vitamin C) in food and beverages. This electrochemical sensor provides accurate results with a low detection limit and long-term stability.
Area of Science:
- Electrochemistry
- Analytical Chemistry
- Materials Science
Background:
- Electrocatalytic determination of ascorbate is crucial for food quality analysis.
- Existing sensors often suffer from high operating potentials or limited stability.
Purpose of the Study:
- To develop an improved electrochemical sensor for sensitive ascorbate detection.
- To characterize and optimize the sensor for practical applications.
Main Methods:
- Fabrication of copper hexacyanoferrate films on carbon electrodes via electrochemical and chemical deposition.
- Characterization using cyclic voltammetry and electrochemical impedance spectroscopy.
- Amperometric detection of ascorbate at a low applied potential (+0.05 V vs. SCE).
Main Results:
- Chemically deposited films demonstrated superior performance for ascorbate determination.
- The sensor exhibited a linear range up to 5 mM with a low limit of detection (2.1 µM).
- The sensor showed excellent stability, functioning for over four months and continuous use for at least 20 days.
Conclusions:
- The developed sensor provides a sensitive, stable, and low-potential method for ascorbate quantification.
- This technology is suitable for analyzing ascorbate in real-world samples like wines and juices.
- The sensor represents a significant improvement for electrochemical ascorbate determination.