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Hauke A, Kumar LSS, Kim MY, Pegan J, Khine M, Li H, Plaxco KW, Heikenfeld J. Superwetting and aptamer functionalized shrink-induced high surface area electrochemical sensors. Biosens Bioelectron 2017; 94:438-442. [PMID: 28334628 DOI: 10.1016/j.bios.2017.03.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 03/10/2017] [Accepted: 03/11/2017] [Indexed: 12/15/2022]
Abstract
Electrochemical sensing is moving to the forefront of point-of-care and wearable molecular sensing technologies due to the ability to miniaturize the required equipment, a critical advantage over optical methods in this field. Electrochemical sensors that employ roughness to increase their microscopic surface area offer a strategy to combatting the loss in signal associated with the loss of macroscopic surface area upon miniaturization. A simple, low-cost method of creating such roughness has emerged with the development of shrink-induced high surface area electrodes. Building on this approach, we demonstrate here a greater than 12-fold enhancement in electrochemically active surface area over conventional electrodes of equivalent on-chip footprint areas. This two-fold improvement on previous performance is obtained via the creation of a superwetting surface condition facilitated by a dissolvable polymer coating. As a test bed to illustrate the utility of this approach, we further show that electrochemical aptamer-based sensors exhibit exceptional signal strength (signal-to-noise) and excellent signal gain (relative change in signal upon target binding) when deployed on these shrink electrodes. Indeed, the observed 330% gain we observe for a kanamycin sensor is 2-fold greater than that seen on planar gold electrodes.
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Affiliation(s)
- A Hauke
- Novel Devices Laboratory, School of Electronics and Computing Systems, University of Cincinnati, Cincinnati, OH 45221, USA
| | - L S Selva Kumar
- Novel Devices Laboratory, School of Electronics and Computing Systems, University of Cincinnati, Cincinnati, OH 45221, USA
| | - M Y Kim
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92697, USA
| | - J Pegan
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92697, USA
| | - M Khine
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92697, USA
| | - H Li
- Department of Chemistry and Center for Bioengineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - K W Plaxco
- Department of Chemistry and Center for Bioengineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - J Heikenfeld
- Novel Devices Laboratory, School of Electronics and Computing Systems, University of Cincinnati, Cincinnati, OH 45221, USA.
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