An Integrated Biosensor System With a High-Density Microelectrode Array for Real-Time Electrochemical Imaging
IEEE Transactions on Biomedical Circuits and Systems
|November 22, 2019
Summary
This study presents a novel electrochemical imaging system using a custom CMOS microchip with 16,064 microelectrodes for high-resolution chemical gradient analysis. The system enables sensitive detection of neurotransmitters and dissolved oxygen, advancing life science research.
Area of Science:
- * Life Sciences
- * Analytical Chemistry
- * Electrical Engineering
Background:
- * Electrochemical methods are vital for life science research, including metabolism, DNA analysis, and neurotransmitter signaling.
- * Microelectrode Arrays (MEAs) integrated with CMOS technology enable high-density electrochemical sensing.
- * Cellular-level chemical gradient imaging requires advanced sensing systems.
Purpose of the Study:
- * To describe a novel electrochemical imaging system with a custom CMOS microchip.
- * To demonstrate the system's capability for cellular-level chemical gradient imaging.
- * To validate the system's sensitivity, selectivity, and spatiotemporal performance.
Main Methods:
- * Development of a custom CMOS microchip with a 3.6 mm × 3.6 mm sensing area, featuring 16,064 Pt MEAs and integrated read channels.
- * Implementation of a three-electrode system geometry with a 27.5 μm spatial pitch for high-resolution imaging.
- * Characterization of amperometric detection for norepinephrine (NE) and dissolved oxygen (DO), and cyclic voltammetry for analyte selectivity.
- * Integration of an indium tin oxide/Au glass electrode for pH measurement to ensure bio-sample viability.
Main Results:
- * The system achieved sensitive amperometric detection of norepinephrine (4.7 pA/μM sensitivity, R² = 0.98) and dissolved oxygen (86 pA/mg/L sensitivity, R² = 0.89).
- * Demonstrated selectivity for simultaneous detection of NE and uric acid using cyclic voltammetry.
- * Confirmed spatiotemporal performance with electrochemical imaging at four frames per second.
- * Ensured bio-sample viability during experiments with integrated pH measurement.
Conclusions:
- * The developed electrochemical imaging system offers high spatiotemporal resolution for chemical gradient analysis.
- * The system demonstrates significant potential for real-time monitoring of biological processes at the cellular level.
- * The integration of CMOS technology and MEAs provides a powerful platform for advancing electrochemical sensing in life sciences.
