Enhancing Glucose Biosensing with Graphene Oxide and Ferrocene-Modified Linear Poly(ethylenimine)

Area of Science:

• Electrochemistry
• Biosensors
• Materials Science

Background:

• Glucose biosensors are crucial for monitoring blood glucose levels.
• Improving sensitivity and electron transfer efficiency is key for biosensor development.
• Screen-printed electrodes offer a cost-effective platform for electrochemical sensing.

Purpose of the Study:

• To design and optimize a highly sensitive glucose biosensor system.
• To enhance the electroactive surface area and electron transfer efficiency of the biosensor.
• To integrate the biosensor into a flow injection system for rapid and reproducible analysis.

Main Methods:

• Screen-printed electrode modification with NAD-GDH enzyme, graphene oxide (GO), and ferrocene-modified linear poly(ethylenimine) (LPEI-Fc).
• Utilizing electrostatic interactions between negatively charged GO and positively charged LPEI-Fc for enhanced performance.
• Amperometric detection at a constant applied potential of 0.35 V within a flow injection (FI) system.

Main Results:

• Achieved enhanced electroactive surface area and electron transfer efficiency.
• Demonstrated increased catalytic current for glucose oxidation, improving detection sensitivity.
• Obtained a linear calibration curve for glucose concentrations from 1.0-40 mM (R² = 0.986).

Conclusions:

• The developed glucose biosensor exhibits high sensitivity and efficiency.
• The integrated FI system ensures swift, reproducible, and contamination-free glucose detection.
• The biosensor successfully quantified glucose in a commercial sports drink, demonstrating practical applicability.