Superwetting and aptamer functionalized shrink-induced high surface area electrochemical sensors.
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.
Novel Devices Laboratory, School of Electronics and Computing Systems, University of Cincinnati, Cincinnati, OH 45221, USA.
A
A
Hauke
Novel Devices Laboratory, School of Electronics and Computing Systems, University of Cincinnati, Cincinnati, OH 45221, USA.
L S Selva
LSS
Kumar
Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92697, USA.
M Y
MY
Kim
Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92697, USA.
J
J
Pegan
Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92697, USA.
M
M
Khine
Department of Chemistry and Center for Bioengineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
H
H
Li
Department of Chemistry and Center for Bioengineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
K W
KW
Plaxco
Novel Devices Laboratory, School of Electronics and Computing Systems, University of Cincinnati, Cincinnati, OH 45221, USA. Electronic address: heikenjc@ucmail.uc.edu.
J
J
Heikenfeld
D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D007612:Kanamycin / Q000737:chemistry / Q000302:isolation & purification*; D013499:Surface Properties
D052157:Aptamers, Nucleotide; D007612:Kanamycin; D006046:Gold
Aptamer; Miniature; Point-of-care; Sensors; Shrink electrode; Superwetting