objective(s): this paper describes a selective and sensitive biosensor based on the dissolution and aggregation of aptamer wrapped single-walled carbon nanotubes. we report on the direct detection of aptamer–cocaine interactions, namely between a dna aptamer and cocaine molecules based on near-infrared absorption at λ807. materials and methods: first a dna aptamer recognizing cocaine was non-co...

We fabricated field-effect transistors based on individual singleand multi-wall carbon nanotubes and analyzed their performance. Transport through the nanotubes is dominated by holes and, at room temperature, it appears to be diffusive rather than ballistic. By varying the gate voltage, we successfully modulated the conductance of a single-wall device by more than 5 orders of magnitude. Multi-w...

The microscopic network structure of surfactant-stabilized single-wall carbon nanotubes (SWNTs) in water was investigated as a function of SWNT concentration in the semidilute (overlapping) regime using small-angle neutron scattering (SANS). Most of the samples exhibit rigid rod behavior (i.e., Q(-1) intensity variation) at large scattering wavevector, Q, and a crossover to network behavior (i....

Polymer-single wall carbon nanotube (SWNT) composite films were prepared and characterized as part of an effort to develop polymeric materials with improved combinations of properties for potential use on future spacecraft. Next generation spacecraft will require ultra-lightweight materials that possess specific and unique combinations of properties such as radiation and atomic oxygen resistanc...

We observe twofold shell filling in the spectra of closed one-dimensional quantum dots formed in single-wall carbon nanotubes. Its signatures include a bimodal distribution of addition energies, correlations in the excitation spectra for different electron number, and alternation of the spins of the added electrons. This provides a contrast with quantum dots in higher dimensions, where such spi...

Single walled carbon nanotubes represent the future of structural aerospace vehicle systems due to their unparalleled strength characteristics and demonstrated multifunctionality. This multifunctionality rises from the CNT’s unique capabilities for both metallic and semiconducting electron transport, electron spin polarizability, and band gap modulation under strain. By incorporating the use of...

Antonis N. Andriotis,*Madhu Menon, Deepak Srivastava, and Leonid Chernozatonskii Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas, P.O. Box 1527, 71110 Heraklio, Crete, Greece Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506-0055 Center for Computational Sciences, University of Kentucky, Lexington, Kentucky 40506-00...

Electrophoresis, the motion of charged species through liquids and pores under the influence of an external electric field, has been the principle source of chemical pumping for numerous micro- and nanofluidic device platforms. Recent measurements of ion currents through single or few carbon nanotube channels have yielded values of ion mobility that range from close to the bulk mobility to valu...

first principles calculations were carried out for investigation the novel 7-hydroxycoumarinyl gallates derivatives in gas and liquid phases using density functional theory (dft) method. computational chemistry simulations were carried out to compare calculated quantum chemical parameters for gallates derivatives. all calculations were performed using dmol3 code which is based on dft. the doubl...

Room-temperature single-electron transistors are realized within individual metallic single-wall carbon nanotube molecules. The devices feature a short (down to approximately 20 nanometers) nanotube section that is created by inducing local barriers into the tube with an atomic force microscope. Coulomb charging is observed at room temperature, with an addition energy of 120 millielectron volts...