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Chemical force microscopy was used to study adhesive forces between surfaces of epoxy resin and self-assembled monolayers that are capable of hydrogen bonding to various extents. It was shown that the trends in the magnitude of the adhesion forces for chemically heterogeneous systems measured with chemical force microscopy can be rationalized quantitatively using surface tension components method.

Research is presented concerning the use of magnetic feedback chemical force microscopy on an aqueous solution of carboxyl- and hydroxyl-terminated self-assembled monolayers to determine the force profile between the monolayers.

Electrical transport measurements were used to prepare and characterize single-crystal n-type and p-type silicon nanowires.

It is possible for MoO3 nanocrystals with a layered structure to adhere to one sliding interface as a spacer. The nanocrystals then maintain a constant sliding contact area under different loads and produce load-independent friction.

Research was conducted to examine fibrillization of the amyloid protofibrils of Alzheimer's disease using atomic force microscopy. The data show that protofibrils growth is dependent on their concentration, ionic strength of the medium and temperature and their number decreasing with time indicates coalescence prior to their elongation and fibrillization.

The interactions between ionizable and neutral functional groups in aqueous solutions were analyzed by chemical force microscopy utilizing self-assembled monolayers (SAMs) terminating in distinct functional groups. Analysis of electrostatic forces and dissociation reactions in an aqueous medium by atomic force microscopy tips modified with SAMs indicated the dependence of the friction coefficient of -COOH-terminated surfaces on hydrogen-ion concentration.

Measurement of adhesion and friction force between probe tips and substrates covalently attached to self-assembled monolayers terminating in distinct functional groups shows that the interaction between COOH/COOH is greater than CH3/CH3 and is greater than COOH/CH3. Experimental results indicate that friction force between different functional groups is related to the adhesion force between the same groups which forms the basis for chemical force microscopy.

A series of thin film materials were grown using pulsed laser deposition (PLD) to study its structure. Results show that PLD synthesis leads to the formation of single phase metastable materials that have a layered, tetragonal structure and the structure and the tetragonal structure is obtained over a wide range of x and delta stoichiometries. Physical studies have shown that the electrical properties change with the variations in this stoichiometries.

A facile synthesis of single crystalline ultrathin Au nanowires (NWs) by reduction of HAu[Cl.sub.4] in oleic acid and oleylamine and their transport properties are described. The studies have shown that the chemically made ultrathin single crystalline Au NWs are used as a molecular-scale interconnects for nanoelectronic applications.

Energy dissipation chemical force microscopy was used to analyze the dissipative properties of chemically similar regions of hydroxyl- and carboxyl-terminated self-assembled monolayers (SAMs) on gold with a hydroxyl-terminated tip. Viscosity of the confined water increased slightly over that of the bulk, and SAM deformation was found to have a longer retardation time than restructuring of interfacial ions and solvent during tip-sample contact.

The Brownian force profile reconstruction (BFPR) was used to measure the solvent structure force profile of interfacial 1-nonanol between graphite and methyl terminated alkane thiol SAM surfaces. The technique could be useful to investigate the solvent structure or more biologically relevant interactions such as single ligand-receptor binding and protein folding landscapes.

Single-source molecular precursors were used for the synthesis of CdS and ZnS nanowires. The synthesis resulted in high yield single-crystal nanowires with controlled diameters and high-quality optical properties.

Biological systems have evolved biochemical, electrical, mechanical, and genetic networks to perform essential functions across various length and time scales. High-aspect-ratio biological nanowires, such as bacterial pili and neurites, mediate many of the interactions and homeostasis in and between these networks. Synthetic materials designed to mimic the structure of biological nanowires could also incorporate similar functional properties, and exploiting this structure-function relationship has already proved fruitful in designing biointerfaces. Semiconductor nanowires are a particularly promising class of synthetic nanowires for biointerfaces, given (1) their unique optical and electronic properties and (2) their high degree of synthetic control and versatility. These characteristics enable fabrication of a variety of electronic and photonic nanowire devices, allowing for the formation of well-defined, functional bioelectric interfaces at the biomolecular level to the whole-organ level. In this Focus Review, we first discuss the history of bioelectric interfaces with semiconductor nanowires. We next highlight several important, endogenous biological nanowires and use these as a framework to categorize semiconductor nanowire-based biointerfaces. Within this framework we then review the fundamentals of bioelectric interfaces with semiconductor nanowires and comment on both material choice and device design to form biointerfaces spanning multiple length scales. We conclude with a discussion of areas with the potential for greatest impact using semiconductor nanowire-enabled biointerfaces in the future. [ABSTRACT FROM AUTHOR]

Research points out that the electronic properties of defect-free single-walled nanotubes depend both on radius and chirality as well as their curvature and local environment. One-dimensional single-walled nanotubes are employed to study interactions between magnetic clusters and one-dimensional electron hosts.

A general synthetic method has been developed to control the diameter and length of nanowires during growth. This approach exploits monodisperse nanocluster catalysts to define both the nanowire diameter and the initiation of nanowire elongation during growth by a vapor-liquid-solid mechanism.

The study demonstrates simple and high yield means of producing individual nanometer and sub-nanometer diameter of single-walled carbon nanotubes (SWNTs) tips for atomic force microscopy (AFM) and other scanning probe microscopies. SWNT tips offer significant advantages for AFM applications in structural biology and could spatially resolve functional imaging and single molecular spectroscopy.

Nanometer-scale crystals of the two-dimensional oxide molybdenum trioxide (MoO3) were formed atop the transition metal dichalcogenides MoS2 and MoSe2. The MoO3 nanocrystals are partially commensurate with the dichalcogenide substrates, being aligned only along one of the substrate's crystallographic axes. These nanocrystals can be slid only along the aligned direction and maintain their alignment with the substrate during motion. Using an AFM probe to oscillate the nanocrystals, it was found that the lateral force required to move them increased linearly with nanocrystal area. The slope of this curve, the interfacial shear strength, was significantly lower than for macroscale systems. It also depended strongly on the duration and the velocity of sliding of the crystal, suggesting a thermal activation model for the system. Finally, it was found that lower commensuration between the nanocrystal and the substrate increased the interfacial shear, a trend opposite that predicted theoretically. [ABSTRACT FROM AUTHOR]

The diameter-selective synthesis of semiconductor nanowires is described.

The bulk synthesis of single crystalline GaN nanowires is reported.

The first growth of single-walled carbon nanotubes (SWNTs) directly from conventional atomic force microscopy (AFM) cantilever assemblies for the creation of very high-resolution tips for scanning probe microscopies was reported. The synthesis of carbon nanotubes was done using metal catalysts that were deposited onto the pyramids of microfabricated AFM tips and chemical vapor deposition (CVD). The CVD surface growth method can be applied using simple and inexpensive equipment and has potential for ready implementation at the wafer level for mass production.

Single-walled carbon nanotubes (SWNTs) were covalently altered using a well-defined covalent chemistry to produce high-resolution, chemically sensitive probe microscopy tips. Carboxylic acid groups located at the tips of SWNTs were then coupled to amines to produce other probes with either basic or hydrophobic functionality. The chemical sensitivity and robustness of SWNT tips were validated by force titrations implemented between the ends of the hydroxy-terminated self-assembled monolayers and those of SWNT tips.

The first atomic force microscopic (AFM) imaging studies to consider the potential of carbon nanotube tips for enhancing lateral resolution and examining biological systems was conducted. In these studies, multi-wall carbon nanotubes and single-wall carbon nanotubes were connected to the extremities of single-crystal silicon cantilever tip assemblies. These were utilized for imaging amyloid beta(1-40) derived protofibrils and fibrils through AFM mode. The average resolution achieved using nanotube tubes was much better than that derived using the best silicon tips.

The first mapping of the pressure-temperature-composition diagram for a prototypical sp(super 2)-bonded amorphous carbon nitride material is presented. Experiments reveal that the carbon nitride material undergoes an irreversible decomposition into carbon and molecular nitrogen at a well-defined temperature that rises monotonically with pressure. Among the important implications of these results are the existence of a well-defined decomposition line for the prototypical carbon nitride precursor pCN and that kinetics may play a major role in the synthesis of sp(super 3)-bonded carbon nitrides.

Nano-bioelectronics represents a rapidly expanding interdisciplinary field that combines nanomaterials with biology and electronics and, in so doing, offers the potential to overcome existing challenges in bioelectronics. In particular, shrinking electronic transducer dimensions to the nanoscale and making their properties appear more biological can yield significant improvements in the sensitivity and biocompatibility and thereby open up opportunities in fundamental biology and healthcare. This review emphasizes recent advances in nano-bioelectronics enabled with semiconductor nanostructures, including silicon nanowires, carbon nanotubes, and graphene. First, the synthesis and electrical properties of these nanomaterials are discussed in the context of bioelectronics. Second, affinity-based nano-bioelectronic sensors for highly sensitive analysis of biomolecules are reviewed. In these studies, semiconductor nanostructures as transistor-based biosensors are discussed from fundamental device behavior through sensing applications and future challenges. Third, the complex interface between nanoelectronics and living biological systems, from single cells to live animals, is reviewed. This discussion focuses on representative advances in electrophysiology enabled using semiconductor nanostructures and their nanoelectronic devices for cellular measurements through emerging work where arrays of nanoelectronic devices are incorporated within three-dimensional cell networks that define synthetic and natural tissues. Last, some challenges and exciting future opportunities are discussed. [ABSTRACT FROM AUTHOR]

Pulsed laser ablation and deposition helps prepare the layered copper oxide material Sr2CuO(3 + delta) at low temperatures and pressures. Structural studies of the copper oxide material reveal that it has a layered tetragonal structure with a repeat unit containing a CuO2 plane and two SrO(delta) layers. Mechanistic studies show that this phase is a kinetic product, while solid state reactions produce a thermodynamic product. This kinetic growth model helps synthesize doped metastable copper oxides with various oxygen and cation stoichiometries.

A low-temperature solid-state synthetic method for the preparation of the tetragonal infinite layer phase of SrCuO2 based on pulsed laser deposition (PLD) is presented. The synthesis is performed in a stainless steel vacuum chamber evacuated with a turbomolecular pump. The desired SrCuO2 is synthesized from a 1:1 mixture of SrCO3 and CuO, giving the product in the orthorhombic phase. Ablation and deposition of the orthorhombic SrCuO2 gives the tetragonal layered phase.

The unique structural and electronic properties of single-walled carbon nanotubes (SWNTs) are discussed. Defect-free SWNTs show semiconducting and metallic behaviour that depends on helicity and diameter.