Phasor transform to extract glucose and ascorbic acid data in an amperometric sensor

Area of Science:

• Electrochemistry
• Biosensors
• Analytical Chemistry

Background:

• Simultaneous detection of analytes like glucose and ascorbic acid is challenging due to signal overlap.
• Existing methods often require complex sample preparation or multiple recognition surfaces.

Purpose of the Study:

• To develop a method for separating and quantifying glucose and ascorbic acid signals on a single surface.
• To utilize ac immittance spectroscopy for distinguishing between analytes based on their unique electrochemical characteristics.

Main Methods:

• Employing ac immittance technique to measure electrochemical responses.
• Representing oxidation processes as unique vectors (based on phase angle and admittance magnitude).
• Utilizing enzyme-generated hydrogen peroxide as a mediator for glucose detection.

Main Results:

• Demonstrated separation of signals from ascorbic acid and enzyme-generated hydrogen peroxide.
• Achieved good spatial resolution by identifying characteristic phase angles for each analyte.
• Successfully quantified mixed analytes by transforming total admittance into an 'analyte space' using basis vectors.

Conclusions:

• The ac immittance method effectively distinguishes and quantifies glucose and ascorbic acid simultaneously.
• This approach offers a promising strategy for developing advanced electrochemical biosensors.
• The vector-based analysis provides a robust framework for complex analyte mixtures.