A Glucose Biosensor Using CMOS Potentiostat and Vertically Aligned Carbon Nanofibers

Area of Science:

• Electrical Engineering
• Biomedical Engineering
• Materials Science

Background:

• Amperometric glucose sensors are crucial for diabetes management.
• Vertically aligned carbon nanofibers (VACNF) offer high surface area for enhanced electrochemical performance.
• Existing potentiostats can be bulky, power-hungry, or lack linearity.

Purpose of the Study:

• To develop a linear, low-power, and compact CMOS-based potentiostat tailored for VACNF amperometric glucose sensors.
• To integrate essential potentiostat functionalities onto a single chip for miniaturization.

Main Methods:

• Design and fabrication of a CMOS potentiostat using a 0.18 µm standard process.
• Integration of a single-ended potential control unit, a low-noise transimpedance amplifier, and a low-power voltage-controlled oscillator (VCO).
• Characterization of the potentiostat's current measuring unit for linearity and dynamic range.

Main Results:

• Achieved a linear detection of electrochemical currents from 500 nA to 7 µA.
• The potentiostat demonstrated high linearity across the measured current range.
• Low power consumption of 71.7 µW from a 1.8 V supply.
• Compact chip area of 0.017 mm².

Conclusions:

• The developed CMOS potentiostat is suitable for integration into miniaturized VACNF-based amperometric glucose sensors.
• The design offers a promising solution for low-power, high-performance glucose monitoring systems.
• The linearity and compact size pave the way for portable and efficient electrochemical sensing applications.