Conical nanotubes

Conical Nanotube Manbranes with Uniform Nanopores.541... 

Mimicking Artificial Ion Channel Using DNA-Functionalized Conical Nanotubes.557... 

Conical nanotubes have attracted increased interest because of their asymmetric structure along the axis, which is found to exhibit unique transport properties. The conical-shaped nanotubes and nanopores have been used in many applications including dye-sensitized solar cells, ion rectitier, - lithography, and biosensors. ... 

Conical Nanotube Membranes with Uniform Nanopores... 

FIGURE 20.15 Ionic current-time data in a PEG-modified conical nanotube sensor with tip diameters of 17 nm (top) and 27 nm (bottom) for a prototype BSA analyte. In both cases, the BSA concentration is 100 nM, and the applied transmembrane voltage is 1000 mV. (From Wharton, J.E. et al.. Small, 3, 3424, 2007. With permission.)... 

FIGURE 20.16 (a) Schematic of a conical nanotube sensor with gold and PEG functionalization. The diameters of the tip opening and the... 

FIGURE 20.17 Ionic current-time signal for a conical nanotube with tip diameter opening of 17 nm. (a) Buffer only (b) buffer plus 100 nM BSA (c) buffer only after sensing 100 nM BSA (d) buffer plus 100 nM PhB (e) buffer plus 100 nM pGal (applied transmembrane potential for a through e was 1000 mV) (f) buffer plus 100 nM BSA at an applied transmembrane potential of -1000 mV. (From Sexton, L.T. et al., JACS, 132, 6755, 2010. With permission.)... 

Sexton, L. T. Home, L. P. Sherrill, S. A. Bishop, G. W. Baker, L. A. Martin, C. R. Resistive-pulse studies of proteins and protein/antibody complexes using a conical nanotube sensor. J Am Chem Soc 2007, 129, 13144-13152. 

In Fig. 1 is shown a HRTEM image of part of the end of a PCNT. The initial material consisted of carbon nanotubes upon which bi-conical spindle-like secondary growth had deposited[21], apparently by inhomogeneous deposition of aromatic carbonaceous, presumably disordered, layers on the primary substrate nanotube. Prior to further heat treatment, the second-... 

Another important field where inorganic nanotubes can be useful is as tips in scanning probe microscopy (16). Here, applications in the inspection of microelectronics circuitry have been demonstrated and potential applications in nanolithography are being contemplated. A comparison between a WS2 nanotube tip and a microfabricated Si tip indicates that while the microfabricated conical-shaped Si tip is unable to probe the bottom of deep and narrow grooves, the slender and inert... 

Mor GK, Varghese OK, Paulose M, Mukherjee N, Grimes CA (2003) Fabrication of tapered, conical-shaped titania nanotubes. J Mater Res 18 2588-2593... 

Fig. 23 HREM images of the NbSc2 nanotubes. The tube in (a) has a closed tip with a 90° bend in one corner, while the tube in (b) is near-conical in shape due to several terminated layers in the walls. The inset in (a) shows a typical ED pattern. (Reproduced with permission from ref. 70).

Figure 53 Main types of the crystalline structure of the carbon nanofilaments produced by pyrolysis of hydrocarbons over transition metal nanoparticles coaxial cylindrical (multilayer nanotube) (A), coaxial conical (fishbone) (B), and pile (C). The nanofilaments are 10 nm in characteristic diameter. The catalyst nanoparticle behaves as a nanofilament seed.

Here, we will report on the design, synthesis, characterization, and applications of template-synthesized nanotube membranes. Then, we will briefly review the synthesis of the template-synthesized nanotube membranes. Some details of differential-surface chemistry on nanombes, and nanombes for bioextraction and biocatalysis are presented. We discuss in detail the drug detoxification using functionalized nanotubes [2], and epoenzyme-, enzyme- and antibody-immobilized nanotubes for enantiomeric separations, biocatalysis, and bioextractions [3-5]. We also describe our recent results on DNA-functionalized nanombe membranes with single-nucleotide mismatch selectivity [6], and the fabrication of artificial ion-channel using single-conical nanombe membrane [7]. 

Figure 19 Computer-generated images of carbon nanostructures showing (A) a spherical C60 fullerene Buckyball structure, (B) a conical form, (C) a SWNT and (D) a cylindrical multiwalled CNT MWNT. Abbreviations SWNT, single-walled nanotube MWNT, multiwalled nanotube. Source From Ref. 102.

Figure 3.5 Shapes of caps on asymmetrically closed carbon nanotubes (a) asymmetrical conical tip, (b) tip with inner cap, (c) beak-shaped tip.

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