CMOS-Based Electrochemical Sensing Systems

Complementary metal–oxide–semiconductor (CMOS)-based electrochemical sensing systems integrate microelectronic circuits and electrochemical transducers on a single chip to enable rapid, sensitive analysis of chemical and biological analytes. By embedding potentiostats, transimpedance amplifiers and analogue-to-digital converters directly within the CMOS substrate, these systems achieve unparalleled miniaturisation, low power consumption and high throughput. Advances in fabrication have facilitated the integration of multiple electrodes and sensors, supporting multiplexed assays for applications spanning environmental monitoring, point-of-care diagnostics and wearable health devices. Modern designs leverage noise-cancellation techniques, such as chopper stabilisation and Delta-Sigma modulation, to overcome flicker noise and extend detection limits into the picoampere regime. Moreover, innovations in voltage-range expansion and dynamic voltage control permit a broader spectrum of redox reactions, enabling the interrogation of complex electrochemical pathways. The confluence of on-chip microfluidics, inkjet-printed electrodes and advanced CMOS technology nodes paves the way for cost-effective, disposable platforms that retain laboratory-grade performance. Ongoing research focuses on scaling electrode arrays, enhancing data fidelity via on-chip processing and leveraging wireless interfaces to deliver real-time analytical capabilities in distributed settings.

Research from Nature Portfolio

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Research from all publishers

Recent work has yielded an ultrasensitive, disposable amperometric platform in which a low-power potentiostatic Delta-Sigma modulator cancels its own flicker noise, achieving a limit of detection of 15 pA_rms and a dynamic range exceeding 110 dB. The 2.3 mm² CMOS chip, coupled with inkjet-printed electrodes, can detect live bacterial concentrations down to 10² CFU/mL in under one hour, illustrating the promise of rapid point-of-care diagnostics. Another study introduced a wide-voltage-swing potentiostat architecture that employs a dynamic analogue ground to expand supported bias potentials by up to 88%, enabling electrochemical reactions requiring voltages beyond conventional CMOS supply limits; the design consumes just over 2 mW in 180 nm technology. A foundational review of CMOS electrochemical instrumentation circuits has illuminated the main functional classes—potentiostats, transimpedance amplifiers and on-chip signal processing—and has synthesised performance trade-offs to guide next-generation integration of electrochemical sensors directly onto CMOS substrates.

CMOS-Based Electrochemical Sensing Systems publication trend

The graph below shows the total number of articles in cmos-based electrochemical sensing systems across all publications each year (not limited to Nature Index journals).

Technical terms

Potentiostat: An electronic circuit that controls the voltage between the working and reference electrodes and measures resulting currents in an electrochemical cell.

Amperometric sensing: A detection method that quantifies analyte concentration by measuring current produced by a redox reaction at a fixed potential.

Flicker noise (1/f noise): Low-frequency electronic noise that degrades signal fidelity, particularly in integrated potentiostats and amplifiers.

Delta-Sigma modulator: A data converter architecture that shapes quantisation noise outside the band of interest to enhance resolution in low-frequency measurements.

Dynamic analogue ground: A circuit technique that shifts the reference potential of an electrode to extend the usable voltage range of an integrated potentiostat.

References

1. Ultrasensitive bacterial sensing using a disposable all-in-one amperometric platform with self-noise cancellation. Biosensors and Bioelectronics (2023).
2. Wide Voltage Swing Potentiostat with Dynamic Analog Ground to Expand Electrochemical Potential Windows in Integrated Microsystems. Sensors (2024).
3. CMOS Electrochemical Instrumentation for Biosensor Microsystems: A Review. Sensors (2016).