Flexible Enzymatic Glucose Electrochemical Sensor Based on Polystyrene-Gold Electrodes

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Materials Science

Background:

• Metabolic disorders like diabetes necessitate continuous glucose monitoring.
• Current invasive methods for blood glucose measurement pose challenges.
• Non-invasive glucose monitoring using alternative body fluids is highly desirable.

Purpose of the Study:

• To develop a reliable enzymatic glucose biosensor on flexible foil.
• To enable non-invasive glucose monitoring through sweat analysis.
• To present a versatile nanoimprinting process for microfluidic applications.

Main Methods:

• Fabrication of an enzymatic sensing layer on flexible polystyrene foil.
• Modification of a gold electrode with cysteine and glutaraldehyde for enzyme immobilization.
• Chronoamperometric measurements in PBS buffered glucose solution at 0.65 V and 0.7 V.

Main Results:

• Linear range of 0.025 mM to 2 mM and operational range of 0.025 mM to 25 mM.
• Sensitivity of 1.76µA/mM/cm² and limit of detection (LOD) of 0.055 mM at 0.7 V.
• Apparent Michaelis-Menten constants computed as 3.34 mM (0.7 V) and 0.445 mM (0.65 V).

Conclusions:

• The developed glucose biosensor offers a wide operational range suitable for point-of-care testing.
• The low LOD and linear range make it ideal for non-invasive sweat sensing wearables.
• The versatile nanoimprinting process facilitates microfluidic fabrication for biosensor applications.