JoVE Logo
Faculty Resource Center

Sign In





Representative Results






Synthesis and Functionalization of Nitrogen-doped Carbon Nanotube Cups with Gold Nanoparticles as Cork Stoppers

Published: May 13th, 2013



1Department of Chemistry, University of Pittsburgh

We discussed the synthesis of individual graphitic nanocups using a series of techniques including chemical vapor deposition, acid oxidation and probe-tip sonication. By citrate reduction of HAuCl4, the graphitic nanocups were effectively corked with gold nanoparticles due to the chemically reactive edges of the cups.

Nitrogen-doped carbon nanotubes consist of many cup-shaped graphitic compartments termed as nitrogen-doped carbon nanotube cups (NCNCs). These as-synthesized graphitic nanocups from chemical vapor deposition (CVD) method were stacked in a head-to-tail fashion held only through noncovalent interactions. Individual NCNCs can be isolated out of their stacking structure through a series of chemical and physical separation processes. First, as-synthesized NCNCs were oxidized in a mixture of strong acids to introduce oxygen-containing defects on the graphitic walls. The oxidized NCNCs were then processed using high-intensity probe-tip sonication which effectively separated the stacked NCNCs into individual graphitic nanocups. Owing to their abundant oxygen and nitrogen surface functionalities, the resulted individual NCNCs are highly hydrophilic and can be effectively functionalized with gold nanoparticles (GNPs), which preferentially fit in the opening of the cups as cork stoppers. These graphitic nanocups corked with GNPs may find promising applications as nanoscale containers and drug carriers.

With their inherent inner cavities and versatile surface chemistry, hollow carbon-based nanomaterials, such as carbon nanotubes (CNTs), are considered to be good nanocarriers in drug delivery applications.1,2 However, the fibril structure of pristine CNTs has rather inaccessible hollow interiors and may cause severe inflammatory response and cytotoxic effects in biological systems.3,4 Nitrogen-doped CNTs, on the other hand, have been found to possess higher biocompatibility than undoped multiwalled carbon nanotubes (MWCNTs)5,6 and may have better drug delivery performance. Doping of nitrogen atoms into the nanotube graphitic lattices r....

Log in or to access full content. Learn more about your institution’s access to JoVE content here

1. CVD Synthesis of Nitrogen-doped Carbon Nanotube Cups (NCNCs)

NCNCs were synthesized employing chemical vapor deposition (CVD) technique on quartz substrate using liquid precursors (Figure 1A).

  1. Place a 3 ft long quartz tube (2.5 cm i.d.) in a Lindberg/Blue tube furnace as the reaction chamber. Place a quartz plate (1" × 12") inside the tube as the substrate for product collection. Seal the quartz tube using homemade stainless steel caps with built-in gas an.......

Log in or to access full content. Learn more about your institution’s access to JoVE content here

The as-synthesized NCNCs from CVD growth appeared as a carpet of black material on quartz substrate. Thick films of NCNCs weighing about several mg were obtained by peeling with a razor blade (Figure 1B). TEM images show the morphology of as-synthesized NCNCs at different magnifications (Figure 1). At the lower magnification (Figure 1C), the as-synthesized NCNCs all showed a fibril structure with lengths of typically several micrometers and diameters of 20 - 30 nm. Unlik.......

Log in or to access full content. Learn more about your institution’s access to JoVE content here

The primary goal of our experiments was to effectively produce graphitic nanocups from nitrogen-doped CNTs. However, nitrogen-doping in the CVD synthesis does not guarantee the formation of the stacked cup-shaped structure. Depending on the chemical composition of the precursor and other growth conditions, the morphology of the resulted product may vary a lot.19 The concentration of nitrogen source is the primary factor influencing the structure because the compartmented structure results from the incompatibil.......

Log in or to access full content. Learn more about your institution’s access to JoVE content here

This work was supported by an NSF CAREER Award No. 0954345.


Log in or to access full content. Learn more about your institution’s access to JoVE content here

Name Company Catalog Number Comments
Reagent Name Company Catalogue Number Comment
H2 Valley National Gases Grade 5.0
Ar Valley National Gases Grade 5.0
Ferrocene Sigma-Aldrich F408-500G
Xylenes Fisher Scientific X5-500
Acetonitrile EMD AXO149-6
H2SO4 Fisher Scientific A300-500
HNO3 EMD NX0409-2
DMF Fisher Scientific D119-500
Ethanol Decon 2716
Phenol Sigma-Aldrich P1037-100G
Pyridine EMD PX2020-6
Hydridantin Sigma-Aldrich H2003-10G
Ninhydrin Alfa Aesar 43846
HAuCl4 Sigma-Aldrich 52918-1G
Sodium Citrate SAFC W302600
CVD Furnace Lindberg/Blue  
TEM (low-resolution) FEI Morgagni  
TEM (high-resolution) JOEL 2100F
Probe-tip Sonicator Qsonica XL-2000
UV-Vis Spectrometer Perkin-Elmer Lambda 900
Zeta Potential Analyzer Brookheaven ZetaPlus
EDX spectroscopy Phillips XL30 FEG

  1. Tasis, D., Tagmatarchis, N., Bianco, A., Prato, M. Chemistry of carbon nanotubes. Chem. Rev. 106 (3), 1105-1136 (2006).
  2. Hilder, T. A., Hill, J. M. Modeling the loading and unloading of drugs into nanotubes. Small. 5 (3), 300-308 (2009).
  3. Shvedova, A. A., Kisin, E. R., et al. Unusual inflammatory and fibrogenic pulmonary responses to single-walled carbon nanotubes in mice. American Journal of Physiology - Lung Cellular and Molecular Physiology. 289 (5), L698-L708 (2005).
  4. Jia, G., Wang, H., et al. Cytotoxicity of carbon nanomaterials: Single-wall nanotube, multi-wall nanotube, and fullerene. Environmental Science & Technology. 39 (5), 1378-1383 (2005).
  5. Carrero-Sánchez, J. C., Elías, A. L., et al. Biocompatibility and toxicological studies of carbon nanotubes doped with nitrogen. Nano Lett. 6 (8), 1609-1616 (2006).
  6. Zhao, M. L., Li, D. J., et al. Differences in cytocompatibility and hemocompatibility between carbon nanotubes and nitrogen-doped carbon nanotubes. Carbon. 49 (9), 3125-3133 (2011).
  7. Allen, B. L., Kichambare, P. D., Star, A. Synthesis, characterization, and manipulation of nitrogen-doped carbon nanotube cups. ACS Nano. 2 (9), 1914-1920 (2008).
  8. Zhao, Y., Tang, Y., Chen, Y., Star, A. Corking carbon nanotube cups with gold nanoparticles. ACS Nano. 6 (8), 6912-6921 (2012).
  9. Stephan, O., Ajayan, P. M., et al. Doping graphitic and carbon nanotube structures with boron and nitrogen. Science. 266 (5191), 1683-1685 (1994).
  10. Suenaga, K., Johansson, M. P., et al. Carbon nitride nanotubulite - densely-packed and well-aligned tubular nanostructures. Chem. Phys. Lett. 300 (5-6), 695-700 (1999).
  11. Chen, H., Yang, Y., et al. Synergism of C5N six-membered ring and vapor-liquid-solid growth of CNx nanotubes with pyridine precursor. J. Phys. Chem. B. 110 (33), 16422-16427 (2006).
  12. Allen, B. L., Keddie, M. B., Star, A. Controlling the volumetric parameters of nitrogen-doped carbon nanotube cups. Nanoscale. 2 (7), 1105-1108 (2010).
  13. Liu, J., Rinzler, A. G., et al. Fullerene pipes. Science. 280 (5367), 1253-1256 (1998).
  14. Zhao, Y., Allen, B. L., Star, A. Enzymatic degradation of multiwalled carbon nanotubes. J. Phys. Chem. A. 115 (34), 9536-9544 (2011).
  15. Wang, Y., Bai, X. High-yield preparation of individual nitrogen-containing carbon nanobells. Mater. Lett. 63 (2), 206-208 (2009).
  16. Heller, D. A., Mayrhofer, R. M., et al. Concomitant length and diameter separation of single-walled carbon nanotubes. J. Am. Chem. Soc. 126 (44), 14567-14573 (2004).
  17. Allen, B. L., Shade, C. M., Yingling, A. M., Petoud, S., Star, A. Graphitic nanocapsules. Adv. Mater. 21 (46), 4692-4695 (2009).
  18. Wang, Z., Shirley, M. D., Meikle, S. T., Whitby, R. L. D., Mikhalovsky, S. V. The surface acidity of acid oxidised multi-walled carbon nanotubes and the influence of in-situ generated fulvic acids on their stability in aqueous dispersions. Carbon. 47 (1), 73-79 (2009).
  19. Liu, H., Zhang, Y., et al. Structural and morphological control of aligned nitrogen-doped carbon nanotubes. Carbon. 48 (5), 1498-1507 (2010).
  20. Mandumpal, J., Gemming, S., Seifert, G. Curvature effects of nitrogen on graphitic sheets: structures and energetics. Chem. Phys. Lett. 447 (1-3), 115-120 (2007).

This article has been published

Video Coming Soon

JoVE Logo


Terms of Use





Copyright © 2024 MyJoVE Corporation. All rights reserved