A fully differential CMOS potentiostat

Dept. of Electr. Eng., California Inst. of Technol., Pasadena, CA, USA
Proceedings - IEEE International Symposium on Circuits and Systems 05/2009; DOI: 10.1109/ISCAS.2009.5118228
Source: IEEE Xplore


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.

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Available from: Meisam Nazari, Mar 19, 2015
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    • "The variation of the surface properties results in a change in the recorded value and waveform features of the redox current, thus indicating the thermodynamics and kinetics of chemical reactions at the sensory interface. In most biochemical sensing applications the recorded redox current is in the range of 100 pA to 100 nA [24], [26], [27]. The reference electrode is set to a constant voltage for constant-potential amperometry (CA) [25], a sinwave for impedance spectroscopy (IS) [42], or a bidirectional ramp voltage for fast-scan cyclic voltammetry (CV) [25] which offers higher chemical selectivity. "
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