Oligodeoxyribonucleotide Association with Single-Walled Carbon Nanotubes Studied by SPM

Roya R. Lahiji, Department of Physics, and Birck Nanotechnology Center, Purdue University
Bridget D. Hines, Department of Medicinal Chemistry and Molecular Pharmacology, and Birck Nanotechnology Center, Purdue University
R. Reifenberger, Department of Physics, and Birck Nanotechnology Center, Purdue University
Donald E. Bergstrom, Department of Medicinal Chemistry and Molecular Pharmacology, and Birck Nanotechnology Center, Purdue University

Abstract

Studies have been performed on both as-received and chemically oxidized single-walled carbon nanotubes (SWCNTs) grown by two different growth methods to better understand the preferential association of the oligodeoxyribonucleotide T30 (ODN) with SWCNTs. Samples of T30 ODN:SWCNT were examined under ambient conditions using noncontact scanning probe microscope (SPM) techniques. The resulting images show different morphologies ranging from tangled networks of SWCNTs to individual, well-dispersed isolated SWCNTs as the sonication time is increased. SPM images of well-dispersed, as-received SWCNTs reveal isolated features that are 1.4 to 2.8 nm higher than the bare SWCNT itself. X-ray photoemission spectroscopy (XPS) confirmed these features to be T30 ODN in nature. Chemically oxidizing the SWCNTs before sonication is found to be an effective way to increase the number of T30 ODN features.