Effects of Carbon Nanotube-Tethered Nanosphere Density on Amperometric Biosensing: Simulation and Experiment

Jonathan Caussen, Purdue University
James Hengenius, Purdue University
Monique Wickner, Purdue University
Timothy Fisher, Purdue University
David Umulis, Purdue University
Marshall Porterfield, Purdue University

Date of this Version



Journal of Applied Physics: Volume 110, Issue 9. doi: 10.1063/1.3656451


Copyright (2011) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Journal of Applied Physics: Volume 110, Issue 9 and may be found at http://dx.doi.org/10.1063/1.3656451. The following article has been submitted to/accepted by Journal of Applied Physics. Copyright (2011) Dhruv Singh, Jayathi Y. Murthy, and Timothy S. Fisher. This article is distributed under a Creative Commons Attribution 3.0 Unported License.


Nascent nanofabrication approaches are being applied to reduce electrode feature dimensions from the microscale to the nanoscale, creating biosensors that are capable of working more efficiently at the biomolecular level. The development of nanoscale biosensors has been driven largely by experimental empiricism to date. Consequently, the precise positioning of nanoscale electrode elements is typically neglected, and its impact on biosensor performance is subsequently overlooked. Herein, we present a bottom-up nanoelectrode array fabrication approach that utilizes low-density and horizontally oriented single-walled carbon nanotubes (SWCNTs) as a template for the growth and precise positioning of Pt nanospheres. We further develop a computational model to optimize the nanosphere spatial arrangement and elucidate the trade-offs among kinetics, mass transport, and charge transport in an enzymatic biosensing scenario. Optimized model variables and experimental results confirm that tightly packed Pt nanosphere/SWCNT nanobands outperform low-density Pt nanosphere/SWCNT arrays in enzymatic glucose sensing. These computational and experimental results demonstrate the profound impact of nanoparticle placement on biosensor performance. This integration of bottom-up nanoelectrode array templating with analysis-informed design produces a foundation for controlling and optimizing nanotechnology-based electrochemical biosensor performance.


Nanoscience and Nanotechnology