An interference-free implantable glucose microbiosensor based on use of a polymeric analyte regulating membrane

Area of Science:

• Biomedical Engineering
• Electrochemistry
• Biosensors

Background:

• Accurate glucose monitoring is crucial for diabetes management.
• Existing glucose biosensors face challenges with selectivity and stability.
• Development of implantable biosensors requires robust analyte-regulating membranes.

Purpose of the Study:

• To develop an implantable glucose microbiosensor with enhanced selectivity and sensitivity.
• To evaluate the performance of a hydrophilic poly(4-vinyl pyridine-co-acrylic acid) (PVP-PAC) overcoating as an analyte-regulating membrane.
• To assess the clinical correlation of the developed biosensor with blood glucose levels.

Main Methods:

• Fabrication of a gold microelectrode with an electrodeposited redox polymer/glucose oxidase (GOX) sensing membrane.
• Application of a poly(4-vinyl pyridine-co-acrylic acid) (PVP-PAC) overcoating, cross-linked with poly(ethylene glycol) diglycidyl ether (PEGDGE).
• Amperometric measurements to determine sensitivity, selectivity, dynamic range, and response time.

Main Results:

• The PVP-PAC overcoated biosensor exhibited high current sensitivity (approx. 220 nA/mM glucose) compared to PVP (approx. 30 nA/mM).
• The biosensor demonstrated excellent selectivity for glucose against oxygen and ascorbic acid.
• A dynamic glucose detection range of 0–30 mM with a response time <10 sec was achieved.
• Clinical trials indicated good correlation between implanted biosensor readings and blood sugar levels.

Conclusions:

• The developed implantable glucose microbiosensor with a PVP-PAC overcoating shows high sensitivity and selectivity.
• The biosensor is a promising device for continuous and accurate glucose monitoring in clinical settings.
• Further validation in extensive clinical trials could establish its utility for diabetes management.