Nanotubes fluorescent

Fig. 10.14 Folic acid can be conjugated onto nanotubes fluorescently labeled nanotubes to target cells expressing folic acid receptors (a,b,c). Nanotubes conjugated with folic acid display a fluorescent signature indicating that nanotubes are internalized by cells expressing folic acid receptors (d). Without the folic acid conjugate, there is very little distribution of nanotubes within the cells as attributed by the lack of fluorescent signature in (e) (Reprinted from Kam et al., 2005. With permission from the National Academy of Sciences, USA) (See Color Plates)...

Sensor fabrication occurs in two steps. The first step is the immobilization of GOx on the surface of the nanotube. This is accomplished by adding GOx to a solution of surfactant stabilized nanotubes and dialyzing away the surfactant. Dialysis is an ideal method for assembling enzymes on a nanotube surface, because the method allows retention of enzyme activity while simultaneously maintaining nanotube colloidal stability. The resulting GOx-S WNT solution exhibits a shift in the nanotube fluorescence indicative of the enzyme layer being less tightly packed around the nanotube than the surfactant layer. The second step is addition of ferricyanide to the GOx-SWNT solution. Adsorption of ferricyanide to the nanotube surface... 

Cherukuri, P. et al. (2006) Mammalian pharmacokinetics of carbon nanotubes using intrinsic near-infrared fluorescence. Proceedings of the National... 

John, G., Mason, M., Ajayan, P.M. and Dordick, J.S. (2004) Lipid-based nanotubes as functional architectures with embedded fluorescence and recognition capabilities. Journal of the American Chemical Society, 2004, 126 (46), 15012-15013. 

Fluorescent nanotubes of polyethyleneimine (PEI) and 3,4,9,10-perylenetetra-carboxylicdianhydride (PTCDA) have been prepared through the alternating deposition of polymers and small functional molecules that form covalent bonds (Figure 7.10) [ 120]. The nanotube synthesis starts with the deposition of P EI in the pores of an AAO membrane as the first layer. The PTCDA solutionis then used to bind to the PEI via covalent bonding (Figure 7.10). The electro-optical properties of the small molecule (PTCDA) are retained in the multilayer films of PEI/PTCDA. The prepared nanotubes retain their fluorescent properties for up to 10 months without... 

Fig. 7.10 Schematic representation of fluorescent nanotubes prepared through the alternate deposition of PEI and PTCDA in AAO membrane templates. (Reproduced from [119] with permission of the American Chemical Society, Copyright 2006 American Chemical Society).

Alvaro, M., Atienzar, P., Bourdelande, J.L., and Garda, H. (2004) An organically modified single wall carbon nanotube containing a pyrene chromophore Fluorescence and diffuse reflectance laser flash photolysis study. Chem. Phys. Lett. 384, 119-123. 

The same group reported the simultaneous radiolabeling (with DOTA-anchored 4Cu) and fluorescence studies, coupled with biodistribution in vivo and in vitro (92). It is believed that appropriately functionalized SWNTs can efficiently reach tumor tissues in mice with no apparent toxicity (159). Furthermore, water-solubilised carbon nanotubes are nontoxic when taken up by cells even in high concentration (92). These studies have been complemented by the recent PET imaging of water-soluble 86Y labelled carbon nanotubes in vivo (mice) (160,161), to explore the potential usefulness of carbon nanocarriers as scaffolds for drug delivery. The tissue biodistribution and pharmacokinetics of model DOTA functionalized nanotubes have been explored in vivo (mouse model). MicroPET images indicated accumulation of activity mainly in the kidney, liver, spleen, and to a much less... 

Noncontact printing, in microarray fabrication, 16 386 Noncoordinating anions, 16 95 Noncovalent carbon nanotube functionalization, 17 53 Noncovalent fluorescence labeling, 20 519... 

Cherukuri P, Bachilo SM, Litovsky SH, Weisman RB (2004) Near-infrared fluorescence microscopy of single-walled carbon nanotubes in phagocytic cells. J. Am. Chem. Soc. 126 15638-15639. 

Hazani M, Naaman R, Hennrich F, Kappes MM (2003) Confocal fluorescence imaging of DNA-functionalized carbon nanotubes. Nano Lett. 3 153-155. 

Ito T, Sun L, Crooks RM (2003) Observation of DNA transport through a single carbon nanotube channel using fluorescence microscopy. Chem. Commun. 7 1482-1483. 

Rao R, Lee J, Lu Q, Keskar G, Freedman KO, Floyd WC, Rao AM, Ke PC (2004) Single-molecule fluorescence microscopy and Raman spectroscopy studies of RNA bound carbon nanotubes. Appl. Phys. Lett. 85 4228 1230. 

O Connell MJ, Bachilo SM, Huffman CB, Moore VC, Strano MS, Haroz EH, Rialon KL, Boul PJ, Noon WH, Kittrell C, Ma JP, Hauge RH, Weisman RB, Smalley RE (2002) Band gap fluorescence from individual single-walled carbon nanotubes. Science 297 593-596. 

Xiao H, Yang LS, Zou HF, Yang L, Le XC (2007) Analysis of oxidized multi-walled carbon nanotubes in single K562 cells by capillary electrophoresis with laser-induced fluorescence. Anal Bioanal Chem 387 119-126. 

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