A Fully Differential CMOS Potentiostat

Dept. of Electr. Eng., California Inst. of Technol., Pasadena, CA, USA
01/2009; DOI: 10.1109/ISCAS.2009.5118228
Source: IEEE Xplore

ABSTRACT A CMOS potentiostat for chemical sensing in a
noisy environment is presented. The potentiostat measures bidirectional
electrochemical redox currents proportional to the
concentration of a chemical down to pico-ampere range. The fully
differential architecture with differential recording electrodes
suppresses the common mode interference. A 200μm×200μm
prototype was fabricated in a standard 0.35μm standard CMOS
technology and yields a 70dB dynamic range. The in-channel
analog-to-digital converter (ADC) performs 16-bit current-tofrequency
quantization. The integrated potentiostat functionality
is validated in electrical and electrochemical experiments.

  • [Show abstract] [Hide abstract]
    ABSTRACT: A novel system for remote monitoring of metabolism in an animal model is proposed in this paper. The system is obtained by integrating bio-nano-sensors to detect single-metabolites, an electrochemical front-end made with off-the-shelf components, a radio frequency communication sub-system, and an antenna of new design. The system has been calibrated and tested for continuous monitoring of four different metabolites: glucose, lactate, glutamate, and adenosine triphosphate. Tests using animal models (mice) have been conducted to investigate tissue inflammation induced by the implanted bio-nano-sensors. These tests confirm that our system is suitable and reliable for remote monitoring of single-metabolites in experiments with animal models.
    IEEE Sensors Journal 03/2013; 13(3):1018-1024. · 1.85 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A simple three-electrode CMOS interface system for electrochemical sensor is described. To maintain a constant potential between the reference electrode (RE) and working electrode (WE), only one differential difference amplifier (DDA) is exploited in this proposed design, while conventional sensor interface system requires at least 2 operational amplifiers and 2 resistors, or more than 3 operational amplifiers and 4 resistors for low voltage differential CMOS integrated interface circuits. The DDA with rail-to-rail design not only enables the full range operation to supply voltage but also provides simple interface system with small hardware and low power consumption. This new interface system was implemented in a 0.35um standard CMOS technology and experimentally verified.
    Circuits and Systems (APCCAS), 2012 IEEE Asia Pacific Conference on; 01/2012
  • [Show abstract] [Hide abstract]
    ABSTRACT: Real-time and multi-target detection by wireless implantable devices is of increasing interest for chronic patients. In this work, electrode sharing is proposed to minimize the size of the implantable device when several three-electrode-based sensing sites are needed. An integrated potentiostat and readout circuit for a multi-target biosensor is presented. To realize this, the circuit reads out the sensor current through each working electrode in a current-mode scheme. The maximum detectable current is 8 μA and the simulated input referred current noise of the circuit is 125 pA/√Hz at 1 Hz. The circuit was fabricated in 0.18 μm technology and tested for two lactate biosensors fabricated with a commercial lactate oxidase and an engineered one. Chronoamperometry experiments performed with the circuit agree well with a commercial equipment for lactate detection up to 1 mM.
    IEEE Biomedical Circuits and Systems Conference (BioCAS 2012), Hsinchu, Taiwan; 11/2012

Full-text (3 Sources)

Available from