Elemental analysis of single-walled carbon nanotubes for cytotoxicity studies

CHED 307

Erin Kate Walker, erinkatewalker@yahoo.com, Meredith Daigrepont, Robert Azad, and Paul Pantano, pantano@utdallas.edu. Department of Chemistry, The University of Texas at Dallas, PO Box 830688 Mail Station BE26, Richardson, TX 75080
In the field of nanomedicine, a key question is whether reports of carbon nanotube (CNT) cytotoxicity are due to impurities from the sample or from the CNTs themselves. Regrettably, reports continue to be published without thorough material characterizations of potential metal and carbonaceous impurities. Recently, our group reported that purified HiPCO and CoMoCAT single-walled CNTs (SWCNTs), dispersed in cell culture media, were taken-up by HeLa cells and did not affect morphologies and growth rates – evidence that SWCNTs inside cells were not toxic under these conditions.[1,2] In this work, an extremely useful technique for determining impurities in CNT samples is thermal gravimetric analysis (TGA). Herein, TGA and ICP-MS are performed on CoMoCAT SWCNT powders and the SWCNTs dispersions exposed to cells. The results indicate that trace impurities present in the as-received powders are removed using our sonication/centrifugation sample preparation protocol.

1. Yehia et al. 2006, submitted. 2. Chin et al. 2006, submitted.