Mediatorless amperometric glucose biosensing using 3-aminopropyltriethoxysilane-functionalized graphene.

Area of Science:

• Electrochemistry
• Biosensors
• Materials Science

Background:

• Accurate blood glucose monitoring is crucial for diabetes management.
• Existing biosensors often require mediators, adding complexity and cost.
• Need for stable, reproducible, and sensitive glucose detection methods.

Purpose of the Study:

• To develop a mediatorless glucose biosensor using graphene-functionalized electrodes.
• To enhance glucose oxidase (GOx) immobilization for improved sensitivity.
• To validate the biosensor's performance for diabetic blood glucose monitoring.

Main Methods:

• Functionalization of glassy carbon electrode (GCE) with graphene using 3-aminopropyltriethoxysilane (APTES).
• Covalent immobilization of glucose oxidase (GOx) onto the graphene-GCE surface via EDC crosslinking.
• Electrochemical detection of glucose at a redox potential of -0.45 V (vs. Ag/AgCl).

Main Results:

• The developed biosensor demonstrated high sensitivity for glucose detection in the 0.5-32 mM range.
• No interference was observed from common electroactive substances or drug metabolites.
• The biosensor showed high production reproducibility and storage stability.
• Validation with artificial blood glucose standards confirmed linearity in the 1.4-27.9 mM range.

Conclusions:

• The graphene-functionalized GCE with immobilized GOx serves as an effective mediatorless glucose biosensor.
• The biosensor exhibits excellent stability, reproducibility, and minimal interference, making it suitable for diabetic monitoring.
• This technology holds promise for commercial mass production of enzyme-bound electrodes for diabetes management.