Synthesis, characterization, and manipulation of nitrogen-doped carbon nanotube cups.

Isolated, carbon nanotube cups with diameters of 12-40 nm have been synthesized by chemical vapor deposition through incorporation of nitrogen atoms into graphitic carbon structure and subsequent mechanical separation. Incorporation of nitrogen affords carbon nanotube cups with a unique composition comprising multiwalled, graphitic lattice with nitrogen groups on the exterior rim and hollow interior cavities. These nanostructures demonstrate the ability to participate in hydrogen bonding because of nitrogen functionalities on their open edges.

Phosphatidylserine targets single-walled carbon nanotubes to professional phagocytes in vitro and in vivo.

Broad applications of single-walled carbon nanotubes (SWCNT) dictate the necessity to better understand their health effects. Poor recognition of non-functionalized SWCNT by phagocytes is prohibitive towards controlling their biological action. We report that SWCNT coating with a phospholipid "eat-me" signal, phosphatidylserine (PS), makes them recognizable in vitro by different phagocytic cells - murine RAW264.

Biodegradation of single-walled carbon nanotubes through enzymatic catalysis.

We show here the biodegradation of single-walled carbon nanotubes through natural, enzymatic catalysis. By incubating nanotubes with a natural horseradish peroxidase (HRP) and low concentrations of H2O2 (approximately 40 microM) at 4 degrees C over 12 weeks under static conditions, we show the increased degradation of nanotube structure. This reaction was monitored via multiple characterization methods, including transmission electron microscopy (TEM), dynamic light scattering (DLS), gel electrophoresis, mass spectrometry, and ultraviolet-visible-near-infrared (UV-vis-NIR) spectroscopy.