Interference Reduction in Glucose Detection by Redox Potential Tuning: New Glucose Meter Development.

Area of Science:

• Electrochemistry
• Biosensors
• Analytical Chemistry

Background:

• Accurate glucose monitoring is crucial for diabetes management.
• Existing glucose sensors face challenges with mediator stability and detection limits.
• Development of novel mediators and sensor designs is essential for improved performance.

Purpose of the Study:

• To develop a novel disposable glucose sensor strip using a new mediator system.
• To synthesize and characterize a new iron complex mediator (Fe-PhenTPy) for the NAD-GDH system.
• To optimize detection potential and electrode alignment for enhanced glucose sensing.

Main Methods:

• Synthesis of 5-(2,5-di(thiophen-2-yl)-1H-pyrrol-1-yl)-1,10-phenanthroline iron(III) chloride (Fe-PhenTPy) mediator.
• Development of a disposable sensor strip with nicotinamide adenine dinucleotide-glucose dehydrogenase (NAD-GDH).
• Optimization of mediator mixture and electrode alignment in a cartridge-type glucose meter.
• Electrochemical characterization using impedance spectrometry.

Main Results:

• The mixed mediator system allowed detection potential tuning below 400 mV (vs. Ag/AgCl).
• Enhanced charge transfer properties were observed with impedance spectrometry.
• The cartridge-type meter with aligned electrodes showed improved response.
• The sensor demonstrated a wide dynamic range (30-500 mg dL⁻¹), reduced interference, and sensitivity of 0.57 μA mM⁻¹.

Conclusions:

• A novel NAD-GDH based glucose sensor employing a mixed iron mediator system was successfully developed.
• The optimized sensor design and mediator composition significantly enhance glucose detection performance.
• This technology holds promise for more accurate and reliable diabetes monitoring devices.