Nanowire, construction

Bates et al. reported the construction and characterization of a gold nanoparticle wire assembled using Mg -dependent RNA-RNA interactions for the future assembly of practical nanocircuits [31]. They used magnesium ion-mediated RNA-RNA loop-receptor interactions, in conjunction with 15 nm or 30 nm gold nanoclusters derivatized with DNA to prepare self-assembled nanowires. A wire was deposited between lithographically fabricated nanoelectrodes and exhibited non-linear activated conduction by electron hopping at 150-300 K (Figure 16). 

Monson, C.F. and Woolley A.T. (2003) DNA templated construction of copper nanowires. Nano Letters, 3,... 

There is considerable interest in developing new types of magnetic materials, with a particular hope that ferroelectric solids and polymers can be constructed— materials having spontaneous electric polarization that can be reversed by an electric field. Such materials could lead to new low-cost memory devices for computers. The fine control of dispersed magnetic nanostructures will take the storage and tunability of magnetic media to new levels, and novel tunneling microscopy approaches allow measurement of microscopic hysteresis effects in iron nanowires. 

Indeed, substantial progress in the application of DNA as a template for the bottom-up construction of metallic NPs or nanowire circuitry, and the assembly of nanoscale miniaturized devices, was demonstrated in the past decade.90... 

The bottom-up synthesis of metallic nanowires was further applied to construct a nanotransistor device.93 The sequence-specific winding of the homologous nucleic acid carried by the RecA-protein into the duplex DNA was used to address the nucleic acid/protein complex on the DNA scaffold (Fig. 12.27). The subsequent association of the anti-RecA antibody to the protein DNA complex, followed by the association of the biotinylated antiantibody, and the linkage of streptavidin-modified carbon nanotube deposited the tubes in the specific domain of the DNA scaffold. The further... 

Figure 12.26 Construction of a nanowire bridging two microelectrodes by the deposition of Ag+ ions on a bridging DNA strand, followed by their chemical reduction to the metallic agglomerate.

Much attention is currently devoted to the synthesis and properties of shape-persistent macrocycles[l]. Such compounds are interesting for a variety of reasons including formation of columnar stacks potentially capable of performing as nanopores for incorporation into membranes or for the generation of nanowires[2]. Furthermore, in shape-persistent macrocycles incorporating coordination units, enc/o-cyclic metal-ion coordination may be exploited to generate nanowires[3], whereas e.ro-cyclic coordination can be used to construct large arrays of polynuclear metal complexes[4]. Shape-persistent macrocycles with reactive substituents may also be linked to other units to yield multicomponent, hierarchical structures. 

Single-walled carbon nanotubes (SWNTs) had been considered for the crossbar components of the defect-tolerant molecular computers but they have been found to be too difficult to handle due to their insolubility and their tendency to form bundles or ropes. Instead, metallic nanowires have become the materials of choice used in the construction of the crossbar devices, with ultrahigh-density lattices and circuits being built, having groups of nanowires 8 nm in diameter and 16 nm apart in layers perpendicular to each other to create nanowire junction densities of 1011 per cm2.52 The process does not depend on self-assembly but rather on molecular beam epitaxy. 

It is probable that rather than using self-assembly to add any active molecules to the device architecture, the nanowires used to construct the devices will be precoated with active molecules via spin coating as shown by Lieber in his recent work.53 Specially doped silicon nanowires have also shown interesting properties in crossbar-based devices.54... 

The utilization of soft templates is helpful for the construction of rare earth hydroxide nanotubes. The s)mthesis of Y(OH)3 nanotubes could be assisted by PEG (Tang et al., 2003) or grafted with PMMA (Li et al., 2004 Mo et al., 2005). Hard templates like A AO are also studied for the fabrication of rare earth hydroxide nanowires (Bocchetta et al., 2007). 

Richter,., Mertig, M., Pompe, W., Monch, I., and Schackert, H. K. Construction of highly conductive nanowires on a DNA template. Appl. Phys. Lett. 2001, 78, 536-538. 

Although different nanomaterials such as nanoparticles, nanowires and nanotubes are used for the construction of biosensor, this chapter is mainly devoted to the use of AuNPs for the construction of electrochemical biosensor and their analytical performances. Further, in this chapter we restrict ourselves in the electrochemical sensing of glucose, ascorbic acid, uric acid and dopamine derivatives using the AuNPs modified electrodes. 

Rolf Konenkamp is the Gertrude-Rempfer Professor of Physics at Portland State University in Portland, Oregon. His present research interests lie in the field of nanoscience. He has worked extensively on semiconductor devices, such as nanostructured solar cells and nanowire light-emitting diodes and transistors, and he holds several patents in this area. He has led the design and construction of a new high-resolution photoelectron microscope since 2002. This will be one of the first aberration-corrected microscopes of this type and it will be used to explore transport and confinement effects on the nanoscale. He has worked at NREL, HMI Berlin, Hitachi Tokyo, Princeton University and at the 1ST in Lisbon, and he is a member of the national R D team for thin-fUm photovoltaics in the US. 

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