Continuous non-diluted serum sample measurement with an ISFET glucose sensor

Area of Science:

• Biomedical Engineering
• Materials Science
• Analytical Chemistry

Background:

• Accurate glucose monitoring is crucial for diabetes management.
• Existing glucose sensors face challenges with non-diluted samples and long-term stability.
• Development of novel sensing platforms is needed for improved point-of-care diagnostics.

Purpose of the Study:

• To fabricate and characterize a novel ion-sensitive field-effect transistor (ISFET) based glucose sensor.
• To evaluate the sensor's performance in continuous measurement of non-diluted human serum.
• To assess the potential of the developed sensor for portable glucose monitoring applications.

Main Methods:

• Fabrication of a sensor chip comprising two ISFETs and a gold electrode.
• Development of a new membrane structure using albumin-glutaraldehyde crosslinking and enzyme immobilization.
• Integration of the sensor into a flow cell for alternate feeding of serum samples and air.
• Continuous monitoring and characterization of sensor response to varying glucose concentrations.

Main Results:

• The novel ISFET glucose sensor exhibited stable responses.
• Sensor output showed a good linear relationship with glucose concentration up to 300 mg/dL.
• The sensor's performance correlated well with a conventional glucose analyzer.
• The device demonstrated effectiveness in analyzing non-diluted serum samples.

Conclusions:

• The newly developed ISFET glucose sensor with an innovative membrane structure is effective for continuous, non-diluted serum glucose measurement.
• The sensor provides stable and accurate readings, comparable to established methods.
• This technology holds significant promise for the development of next-generation portable glucose monitoring devices.