Title: Synthesis of aligned carbon nanotubes by microwave chemical vapour deposition and investigation of their covalent bonding with antibodies for bioapplications

Authors: Jining Xie, Kiran R. Aatre, Vijay K. Varadan, Jithesh V. Veetil, Kaiming Ye

Addresses: Nanomaterials and Nanotubes Research Laboratory, Department of Electrical Engineering, University of Arkansas, Fayetteville, AR 72701, USA. ' Nanomaterials and Nanotubes Research Laboratory, Department of Electrical Engineering, University of Arkansas, Fayetteville, AR 72701, USA. ' Nanomaterials and Nanotubes Research Laboratory, Department of Electrical Engineering, University of Arkansas, Fayetteville, AR 72701, USA. ' Biomedical Engineering Program, College of Engineering, University of Arkansas, Fayetteville, AR 72701, USA. ' Biomedical Engineering Program, College of Engineering, University of Arkansas, Fayetteville, AR 72701, USA

Abstract: Synthesis of aligned carbon nanotubes arrays and their covalent bonding with antibodies for potential antibody-antigen immunosensing are presented. Aligned carbon nanotubes were prepared by a template assisted microwave chemical vapour deposition. This method will produce less amorphous carbon due to the existing temperature gradient. The effect of catalysts for carbon nanotubes growth was studied. A post treatment process was developed to remove the amorphous carbon layer and partially etch the template so that nanotubes tips were exposed. After functionalisation of carbon nanotubes arrays, fluorescence-labelled IgG antibodies were attached to their surface by a two-step process of diimide-activated amidation. The covalent bonding between antibodies and carbon nanotubes arrays was evaluated by a fluorescent microscope. A stronger bonding was observed from functionalised carbon nanotubes than unfunctionalised ones. It is believed that both the alignment of carbon nanotubes and their covalent bonding with antibodies play important roles for immunosensors with high sensitivity and selectivity.

Keywords: carbon nanotubes; CNT arrays; alignment; microwave CVD; chemical vapour deposition; template; functionalisation; scanning electron microscopy; SEM; fluorescent microscopy; antibody-antigen immunosensing; covalent bonding; immunosensors; antibodies.

DOI: 10.1504/IJNP.2008.020267

International Journal of Nanoparticles, 2008 Vol.1 No.2, pp.119 - 135

Published online: 11 Sep 2008 *

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