| Single-Walled Carbon Nanotube Labels and Optical Sensors in Live Cells | ||
| Daniel A. Heller1, Esther S. Jeng2, Tsun-Kwan Yeung3, Brittany M. Martinez4, Anthonie E. Moll4, Seunghyun Baik5, Thomas E. Eurell6 and Michael S. Strano7, (1)Department of Chemistry, University of Illinois at Urbana-Champaign, 104 RAL, Box 93-5, MC-712, 600 S. Mathews Ave., Urbana, IL 61801, (2)Department of Chemistry, University of Illinois at Urbana-Champaign, 104 RAL, MC-712, 600 S. Mathews Ave., Urbana, IL 61801, (3)Department of Physics, University of Illinois at Urbana-Champaign, 104 RAL, MC-712, 600 S. Mathews Ave., Urbana, IL 61801, (4)Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, 104 RAL, MC-712, 600 S. Mathews Ave., Urbana, IL 61801, (5)School of Mechanical Engineering, Sungkyunkwan University, Suwon 440-746, South Korea, (6)Department of Veterinary Biosciences, University of Illinois at Urbana-Champaign, 3223 VMBSB MC-002, 2001 S Lincoln, Urbana, IL 61802, (7)Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, 118 RAL, Box C3-3, MC-712, 600 S. Mathews Ave., Urbana, IL 61801 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. Extended Abstract Status: Not Uploaded | ||