Characterization of coplanar electrode structures for microfluidic-based impedance spectroscopy

SENSORS AND ACTUATORS B-CHEMICAL

卷:218

Article

Blume, Steffen O. P.¹  Ben-Mrad, Ridha¹  Sullivan, Pierre E.¹ 

[1] Univ Toronto, Dept Mech & Ind Engn, Toronto, ON M5S 1A1, Canada

关键词: Digital microfluidics;    Conductivity detection;    Impedance spectroscopy;    Interdigitated electrode structures;   

DOI  :  10.1016/j.snb.2015.04.106

来源: Elsevier

【 摘 要 】

Impedance spectroscopy has the potential for label-free integrated electrochemical detection in microfluidic lab-on-a-chip applications. Its capability to identify and discern between surface and bulk processes in solid-liquid systems finds particular use for the detection of biorecognition events or conductivity measurements. The electrochemical transducer can be in the form of interdigitated electrode structures to increase sensitivity. Experimental work was performed to characterize two different transducer designs. Applications included the monitoring of protein films on contact-less interdigitated electrode structures and conductivity detection of droplets on insulated two-electrode structures. The use of electrode passivation eliminated electrode degradation. Experimental results were compared to theoretical analytical models, and were found to closely correlate with one another. The analytical models were used to design the transducer for optimal conductivity detection. The results inform the current research efforts for the development of in-line impedance spectroscopy in digital microfluidics and confirm the use of simple analytical models for the first-order estimation of the frequency response of interdigitated electrode structures. (C) 2015 Elsevier B.V. All rights reserved.

【 授权许可】

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