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Journal of Sensors
Volume 2009, Article ID 131628, 6 pages
http://dx.doi.org/10.1155/2009/131628
Research Article

The Adsorption Properties of Bacillus atrophaeus Spores on Single-Wall Carbon Nanotubes

1Department of Mechanical & Aerospace Engineering , New Mexico State University, Las Cruces, NM 88003, USA
2Department of Chemical Engineering , New Mexico State University, Las Cruces, NM 88003, USA
3Department of Biology, New Mexico State University, Las Cruces, NM 88003, USA

Received 21 September 2008; Accepted 19 March 2009

Academic Editor: Wojtek Wlodarski

Copyright © 2009 P. Cortes et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

An adsorption equilibrium and a kinetic study of Bacillus atrophaeus on Single-Wall Carbon Nanotubes (SWCNTs) were here performed to provide the basis for developing biosensor devices for detecting threatening micro-organisms in water supply systems. B. atrophaeus spores and carbon nanotubes were subjected to a batch adsorption process to document their equilibria and kinetics. Here, commercial nanotubes were either studied as received or were acid-purified before adsorption experiments. The Bacillus spores appear to show higher affinity towards the purified nanotubes than to the as-received nanomaterial. The effective diffusivity of the spores onto the purified nanotubes was found to be approximately 30 percent higher than onto the as-received nanotubes. It seems that the removal of amorphous carbon from the as-received nanotubes through a purification process yielded an intimate nantoubes-spore interaction as revealed by transmission electron microscopy. Freundlich model successfully correlated the adsorption equilibrium data for the nanotubes-spore interaction. Transmission electron micrographs showed extensive contact between the Bacillus and the purified nanotubes, but the association appeared less intimate between the spores and the as-received nanotubes.