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A new approach for the specific detection and mapping of single molecule recognition based on the nonlinear elastic behavior of a single polymer chain is discussed. It is seen that a polymer chain tethering the ligand to an oscillating cantilevered tip gave rise to a highly anharmonic motion upon ligand-receptor binding.

The concept of the electron-transfer-induced hydrophobocity theory is used to accomplish photoinduced electron transfer between water-oil phases in a water-oil microemulsion system.

Carbon nanotubes have a range of properties which are suitable for use in applications such as atomic force microscopy. They are able to buckle elastically, which makes them strong whilst restricting the maximum force applied to delicate organic and biological samples. Nanotube tips able to chemically and biologically discriminate can be developed with acidic functionality by coupling basic or hydrophobic functionalities. Such modified nanotubes have been used as AFM tips to image patterned samples.

Research was conducted to examine photoinduced electron transfer in pi-donor-capped Zn(II) porphyrins and N,N'-dimethyl-4,4'-bipyridinium supramolecular assemblies. Results indicate that the formation of the complexes prevents the intersystem crossing of the singlet to the triplet state owing to electron-transfer quenching of the excited state by N,N'-dimethyl-4,4'-bipyridinium, MV2+, in the supramolecular assemblies.

The photoinduced electron transfer quenching pathways in supramolecular assemblies of dialkoxybenzene-tethered Ru(II)-tri(bipyridine) derivatives were analyzed to characterize the resulting products. Analysis of the supramolecular assemblies with two-shell dialkoxybenzene-tethered Ru(II)-tris(bipyridine) indicated the absence of an additive effect in the association of the electron transfer units of BXV4+. The pi-donor-acceptor interactions between the bipyridinium cyclophanes also mediated the synergetic association of BVX4+ to the two-shell functionalized sensitizer.

Electron-transfer quenching and charge separation in the series of alkoxyanisyl-tethered Ru(II)-tris(bipyridazine) complexes, acting as photosensitizers, and cyclo[bis(N,N'-bipyridinium)] (BVX4+) salts acting as electron acceptors were examined by steady-state and time-resolved spectroscopy and flash photolysis. Fluorescence spectra revealed rapid intramolecular electron transfer quenching within the supramolecular assemblies. The scheme for the equilibrated supramolecular complexes formed between the photosensitizer series and BXV4+ is included.

The use of atomic force microscopy (AFM) in teaching chemistry students about atoms and molecules is described. AFM gives students a visual idea of the structure of matter and increases their curiosity and excitement.

A concept for molecular electronics exploiting carbon nanotubes as both molecular device elements and molecular wires for reading and writing information was developed. Each device element is based on a suspended, crossed nanotube geometry that leads to bistable, electrostatically switchable ON/OFF states. The device elements are naturally addressable in large arrays by the carbon nanotube molecular wires making up the devices. These reversible, bistable device elements could be used to construct nonvolatile random access memory and logic function tables at an integration level approaching [10.sup.12] elements per square centimeter and an element operation frequency in excess of 100 gigahertz. The viability of this concept is demonstrated by detailed calculations and by the experimental realization of a reversible, bistable nanotube-based bit., In the past several decades, there has been a nearly constant exponential growth in the capabilities of silicon-based microelectronics (1). However, it is unlikely that these advances will continue much [...]

The oriented growth of carbon nanotubes on periodically faceted surfaces is reported. The carbon nanotube graphoepitaxy completes a set of epitaxial modes of nanotube growth that points to interesting new possibilities in nanotechnology.

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.