Continuous, Real-Time Monitoring of Cocaine in Undiluted Blood Serum via a Microfluidic, Electrochemical Aptamer-Based Sensor

Authors

• James S. Swensen, University of California, Santa Barbara
• Yi Xiao, University of California, Santa Barbara
• Brian S. Ferguson, University of California, Santa Barbara
• Arica A. Lubin, University of California, Santa Barbara
• Rebecca Lai, University of Nebraska - LincolnFollow
• Alan J. Heeger, University of California, Santa Barbara
• Kevin W. Plaxco, University of California, Santa Barbara
• H. Tom. Soh, University of California, Santa Barbara

Document Type

Article

Date of this Version

2009

Citation

J Am Chem Soc. 2009 April 1; 131(12): 4262–4266.

Comments

Copyright © 2009 American Chemical Society

Abstract

The development of a biosensor system capable of continuous, real-time measurement of small-molecule analytes directly in complex, unprocessed aqueous samples has been a significant challenge, and successful implementation has been achieved for only a limited number of targets. Towards a general solution to this problem, we report here the Microfluidic Electrochemical Aptamer-based Sensor (MECAS) chip wherein we integrate target-specific DNA aptamers that fold, and thus generate an electrochemical signal, in response to the analyte with a microfluidic detection system. As a model, we demonstrate the continuous, real-time (~1 minute time resolution) detection of the small molecule drug cocaine at near physiological, low micromolar concentrations directly in undiluted, otherwise unmodified blood serum. We believe our approach of integrating folding-based electrochemical sensors with miniaturized detection systems may lay the ground work for the realtime, point-of-care detection of a wide variety of molecular targets.