An amperometric flow-injection analysis biosensor for glucose based on graphite paste modified with...

Area of Science:

• Analytical Chemistry
• Biotechnology
• Electrochemistry

Background:

• Accurate glucose monitoring is crucial for managing diabetes.
• Existing methods for glucose analysis can be time-consuming or require specialized equipment.

Purpose of the Study:

• To develop and evaluate a novel biosensor system for rapid glucose determination in human serum.
• To assess the performance characteristics of the biosensor, including sensitivity, reproducibility, and interference effects.

Main Methods:

• Development of a biosensor using glucose oxidase immobilized in tetracyanoquinodimethane (TCNQ)-modified graphite paste.
• Utilizing flow injection analysis (FIA) for sample introduction and electrochemical detection.
• Testing the sensor's response to varying glucose concentrations, injection volumes, and flow rates.

Main Results:

• The biosensor achieved a detection limit of 2 mM for glucose.
• Excellent reproducibility was observed over 800 injections, with response loss attributed to TCNQ leaching.
• The sensor demonstrated a sample throughput of 20 samples per hour.
• Glucose measurements in human serum showed good agreement with a commercial spectrophotometric method.

Conclusions:

• The developed FIA biosensor system offers a sensitive, reproducible, and efficient method for glucose analysis in human serum.
• The TCNQ-modified electrode shows potential as a mediator for glucose oxidase-based biosensors.
• Further optimization is needed to address TCNQ leaching for long-term stability.