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The cantilever arrays are investigated for real-time detection of Bacillus subtilis spores in liquid medium. The results show that real-time detection of multiple pathogenic organisms is realized by using peptide-functionalized microcantilever arrays.

The significant breakthroughs in the understanding of the physicochemical processes specific to nanometer scale entities can be obtained if the study of the XANES (X-ray absorption near edge structure) part of an absorption spectrum is conducted using a combined full MS and PCA (Principal Component factor Analysis) approach. It is concluded that, the quantitative measurement of the structural parameters coming from the EXAFS analysis constitutes an invaluable starting point for the PCA-FEFF simulation.

Pulsed Field Gradient (PFG) NMR study of the diffusion of H2O, PEG200, PEG1500, PEG8000, and PEG20000 in wet cotton fibers and H2O in wet cotton linters are presented. PFG NMR study has shown new insights and has highlighted some of the strengths and weakness of PFG NMR when applied to relatively complicated systems such as cotton.

A novel approach to the first multicomponent interposed carbon nanotube micropatterns prepared by the simple and effective dry contact transfer method involving a region-selective transfer of the iron (II) phthalocyanine (FePc) generated perpendicularly-aligned carbon nanotubes onto a Scotch tape pre-patterned with a thin layer of heptylamine-plasma-treated silver, followed by region-specific adsorption of acid-oxidized carbon nanotubes interdispersed into the discrete areas in the patterned structure of aligned carbon nanotubes is presented.

The first electrochemical pathway to prepare Au-containing nanocomplexes with the mean diameter of 2 nm in 0.1 N KCI aqueous solutions without addition of any stabilizer is reported. The electrochemical activities of AuCI4-nanocomplexes existing in the aqueous solution during oxidation-reduction cycles (ORC) treatment for roughening Au substrate are found that can be used to fabricate Au/PPy core-shell nanocomposites with extremely high conductivities and further prepare elemental Au(0) nanoparticles.

Self-assembled monolayers of electron donor tetramethyl xylyl dithiol (TMXYL) are synthesized and chemically switched to a conducting state by reaction with an electron acceptor tetracyanoethylene (TCNE). Low bias conductance measurements obtained by scanning tunneling spectroscopy under ultrahigh vacuum conditions reveals a significant change from insulating to ohmic behavior.

We present a method by which multi-harmonic signals acquired during a normal tapping mode (amplitude modulated) AFM scan of a sample in air or vacuum with standard microcantilevers can be used to map quantitatively the local mechanical properties of the sample such as elastic modulus, adhesion, and indentation. The approach is based on the observation that during the tapping mode operation in air or vacuum, the 0th and 2nd harmonic signals of microcantilever vibration are encountered under most operating conditions and can be mapped with sufficient signal to noise ratio. By measuring the amplitude and phase of the driven harmonic as well as the 0th and 2nd harmonic observables, we find analytical/semi-analytical formulas that relate these multi-harmonic observables to local mechanical properties for several classical tip-sample interaction models. Least squares estimation of the local mechanical properties is performed pixel by pixel. The method is validated through computations as well as experimental data acquired on a polymer blend made of Polystyrene and Polyolefin elastomer. [ABSTRACT FROM AUTHOR]

The time response of tuning-fork based sensors can be improved by operating them at higher eigenmodes because a measurement takes at least one oscillation cycle in dynamic force microscopy and the oscillation period of the second eigenmode is only about one sixth of the fundamental mode. Here we study the higher-order eigenmodes of quartz qPlus sensors [Bettac et al., Nanotechnology 20, 264009 (2009); Giessibl and Reichling, Nanotechnology 16, S118 (2005); Giessibl, Appl. Phys. Lett. 76, 1470 (2000); and Giessibl, Appl. Phys. Lett. 73, 3956 (1998)], their equivalent stiffness, and piezoelectric sensitivity, while paying special attention to the influence of the mass and rotary inertia of the sensing tip which is attached to the end of the qPlus quartz cantilever. A combination of theoretical modeling and scanning laser Doppler vibrometry is used to study the eigenmodes of qPlus sensors with tungsten tips. We find that the geometry of tungsten tips can greatly influence the shape, equivalent stiffness, and piezoelectric sensitivity of the second eigenmode of the quartz cantilever. At a critical tip length it is possible to theoretically achieve infinite equivalent stiffness and infinite piezoelectric sensitivity when the tip becomes a perfect node of vibration and beyond this critical tip length the second eigenmode loses its vibration node and the trajectory of the tip reverses with respect to the beam curvature. The findings have major implications for optimizing tip geometry for high-resolution imaging with qPlus sensors using higher eigenmodes. [ABSTRACT FROM AUTHOR]

The sol-gel synthesis of a silica (SiO2) matrix that surrounds ZnO nanoparticles was studied using atomic force microscope (AFM) techniques prior to and just after removal of the nanoparticles. The open silica matrix allows acids to penetrate and cause dissolution and removal of the ZnO nanoparticles. The nanoparticles serve as nanotemplates that allow the formation of cavities (mesopores) inside the silica matrix with comparable shape and size of the nanoparticles. AFM topographic scans revealed the presence of dome-like structures at the surface of the acid-treated silica matrix. Electrostatic force images of these near-surface, dome-like features revealed they have a low dielectric constant relative to the silica matrix, suggesting they are domes over empty cavities. Taken together, these results are consistent with the formation of a novel material consisting of nanotemplated cavities having a volume of ~0.1 attolitres embedded in a silica matrix. [ABSTRACT FROM AUTHOR]