(127c) Single-Walled Carbon Nanotube Labels and Optical Sensors in Live Cells

Authors: 
Heller, D. A., Massachusetts Institute of Technology
Baik, S., Sungkyunkwan University
Moll, A. E., University of Illinois at Urbana-Champaign
Yeung, T., University of Illinois at Urbana-Champaign
Eurell, T. E., University of Illinois at Urbana-Champaign
Strano, M. S., Massachusetts Institute of Technology
Martinez, B. M., University of Illinois at Urbana-Champaign
Jeng, E. S., University of Illinois at Urbana-Champaign


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.