(230d) Corking Carbon Nanotube Cups with Gold Nanoparticles for Drug Delivery Applications

In this talk, I will describe an effective methodology of obtaining nitrogen-doped carbon nanotube cups (NCNCs), which have a hollow multiwall graphitic structure with one end sealed and the other open.  We have previously shown that nitrogen doping is essential to determine the unique morphology and properties of NCNCs.^1,2  Other studies have demonstrated that nitrogen doped carbon nanotubes have better biocompatibility and mitigated cytotoxicity as compared to undoped carbon nanotubes.³  These findings are important when considering NCNCs as potential carriers in drug delivery applications.  Most recently, we have demonstrated⁴ that by applying intense ultrasonication, stacked NCNC fibers, which were prepared by chemical vapor deposition (CVD) technique, can be greatly shortened to afford individual NCNCs with an efficient yield.  Microscopic and spectroscopic characterization confirmed the cup-shaped hollow structure of isolated NCNCs and showed their robust chemical reactivity due to amine groups that are preferentially distributed at the open rims of the cups.  We were further able to cork isolated nanocups with gold nanoparticles (GNPs) by utilizing the localized amine groups as reactive sites.  These nanocup-nanoparticle hybrid structures may find future applications as nanoscale containers and drug delivery carriers.

1. Allen, B. L.; Kichambare, P. D.; Star, A. Synthesis, characterization, and manipulation of nitrogen-doped carbon nanotube cups. ACS Nano 2008, 2, 1914–1920.
2. Tang, Y.; Allen, B. L.; Kauffman, D. R.; Star, A. Electrocatalytic activity of nitrogen-doped carbon nanotube cups.  J. Am. Chem. Soc. 2009, 131, 13200–13201.
3. Castle, A. B.; Gracia-Espino, E.; Nieto-Delgado, C.; Terrones, H.; Terrones, M.; Hussain, S. Hydroxyl-functionalized and N-doped multiwalled carbon nanotubes decorated with silver nanoparticles preserve cellular function.  ACS Nano 2011, 5, 2458–2466.
4. Zhao, Y.; Tang, Y.; Chen, Y.; Star A. Corking carbon nanotube cups with gold nanoparticles. Submitted.