Portable Measurement System for the Characterization of Capacitive Field-Effect Sensors.

Area of Science:

• Materials Science
• Electrical Engineering
• Biomedical Engineering

Background:

• Electrolyte-insulator-semiconductor capacitor (EISCAP) sensors offer potential for point-of-care diagnostics.
• Characterization of EISCAP sensors typically requires stationary, laboratory-based equipment.
• A need exists for portable, user-friendly systems for on-site sensor analysis.

Purpose of the Study:

• To develop and evaluate a portable, low-cost readout system for EISCAP sensor characterization.
• To enable on-site or point-of-care analysis of chemo- and biosensors.
• To facilitate the translation of EISCAP sensors from research to commercial applications.

Main Methods:

• Development of a portable readout system using a commercial impedance analyzer and a custom Python script.
• Implementation of user-selectable characterization modes: impedance spectra, capacitance-voltage, and constant-capacitance.
• Evaluation of the system's performance using Al/p-Si/SiO2/Ta2O5 EISCAP structures for pH measurements and penicillin detection.

Main Results:

• The portable system successfully characterized EISCAP sensors using multiple methods.
• Performance evaluation demonstrated highly similar results compared to a stationary commercial impedance analyzer.
• Recorded EISCAP signals from both systems showed near-perfect overlap, indicating comparable accuracy.

Conclusions:

• The developed portable readout system is effective for on-site EISCAP sensor characterization.
• The system's user-friendliness and low cost support point-of-care applications.
• This technology can significantly accelerate the commercialization of EISCAP-based sensors.