Amperometric biosensors for glucose based on carbon paste modified electrodes

Area of Science:

• Electrochemistry
• Biosensors
• Enzyme immobilization

Background:

• Carbon-paste electrodes are widely used in electrochemical sensing.
• Glucose oxidase (GOD) is a key enzyme for glucose detection.
• Mediators can enhance the performance of enzyme-based biosensors.

Purpose of the Study:

• To develop and characterize carbon-paste electrodes modified with glucose oxidase (GOD).
• To evaluate the performance of these electrodes as amperometric glucose sensors, with and without a mediator.
• To assess the suitability of the developed sensors for plasma glucose determination.

Main Methods:

• Modification of carbon-paste electrodes by incorporating glucose oxidase (GOD).
• Amperometric detection of glucose in the presence and absence of 1,1'-dimethylferrocene mediator.
• Calibration studies to determine linear ranges and response times.
• Correlation of sensor results with spectrophotometric methods for plasma glucose assays.

Main Results:

• The GOD-modified carbon-paste electrodes exhibited extended linear calibration ranges up to 90 mM (without mediator) and 50 mM (with mediator).
• Rapid electrode responses were observed, reaching steady-state values within 30-40 seconds.
• Plasma glucose assays using the developed sensor showed good correlation (r = 0.973) with spectrophotometric determinations.

Conclusions:

• The GOD-modified carbon-paste electrode formulation offers advantages for amperometric glucose sensing.
• The developed sensors provide a reliable and efficient method for glucose determination.
• The formulation demonstrates potential for clinical applications in glucose monitoring.