(127c) Single-Walled Carbon Nanotube Labels and Optical Sensors in Live Cells
AIChE Annual Meeting
2005
2005 Annual Meeting
Biomedical Applications of Nanotechnology (Bionanotechnology)
Nanomaterials for in vivo and in vitro Imaging and Chemical Sensing
Monday, October 31, 2005 - 3:55pm to 4:15pm
Complexes of DNA and single-walled carbon nanotubes (SWNT) exhibit long-lived, modifiable near-infrared fluorescence emission which was used to fabricate long-term labels and optical sensors within cells and tissues. Nanotube fluorescence is in the near-infrared region and does not photobleach under prolonged excitation, permitting continuous monitoring through biological media for experiments lasting several hours.
The transition of the DNA secondary structure from the B to Z conformation was detected via modulation of the intrinsic near-infrared fluorescence of SWNT. A reversible shift in emission energy of DNA-encapsulated nanotubes was found to closely match the thermodynamics of the transition of unbound DNA.
DNA-nanotube complexes were taken into endosomes, situated near the cell nucleus, and remained visible after multiple cell divisions. The sensors demonstrated optical detection of the DNA B-Z transition within mammalian cells, muscle tissue and whole blood.