Two alkyl-substituted dual oligothiophenes, quarterthiophene (4T)-trimethylene (tm)-octithiophene (8T) and 4T-tm-4T, were used to fabricate molecular structures on highly oriented pyrolytic graphite and Au(111) surfaces. The resulted structures were investigated by scanning tunneling microscopy. The 4T-tm-8T and 4T-tm-4T molecules self-organize into long-range ordered structures with linear and...

We demonstrate that the scanning tunneling microscope can be used to obtain information about arrangement of tubulin subunits in the microtubule wall. Long rows of subunits with a periodicity of 3.8 +/- 0.4 nm were clearly visible in the images of microtubules. The separation between the rows of subunits was 4.8 +/- 0.4 nm. Close inspection of two images revealed another periodicity of 7.8 +/- ...

The interference of surface plasmons can provide important information regarding the surface features of the hosting thin metal film. We present an investigation of the interference of optically excited surface plasmons in the Kretschmann configuration in the visible spectrum. Large area surface plasmon interference regions are generated at several wavelengths and imaged with the photon scannin...

The light emission spectra of individual Au nanoparticles induced by a scanning tunneling microscope (STM) have been investigated. Two-dimensional ensembles of tunnel-coupled Au particles were prepared by thermal evaporation onto a native oxide silicon wafer in ultrahigh vacuum (10 – 9 mbar). Our STM measurements show a single peak at photon energy 1.6 eV in the tunneling mode and two peaks at ...

Two-photon scanning microscopy has advanced our understanding of neural signaling in non-mammalian species and mammals. Various developments are needed to perform two-photon scanning microscopy over prolonged periods in non-human primates performing a behavioral task. In striate cortex in two macaque monkeys, cortical neurons were transfected with a genetically encoded fluorescent calcium senso...

Herein, the removal of methyl orange (MO), a monoazo dye, from aqueous solutions was investigated using bimetallic ferromagnetic Fe/Ni nanoparticles (NPs) with the average particle size of 12-16 nm. The effect of contact time, pH, temperature, and Fe/Ni dosage on dye removal process was investigated. The results showed that 60 mg of Fe/Ni NPs at 25 oC and pH= 1 can remove 99.5% of 50 mg/L dye s...

We report scanning tunneling microscopy ~STM! results that reveal localized features on the exposed surface of amorphous aluminum oxide that are regularly present but which cannot be uniquely identified with STM as electronic defects or surface adsorbents. With the simultaneous use of ballistic electron emission microscopy ~BEEM! we can examine the electronic transport properties of these local...

Atomic-scale topography of epitaxial multilayer graphene grown on 4H-SiC(0001) was investigated using scanning tunneling microscopy (STM). Bunched nano-ridges ten times smaller than previously recorded were observed throughout the surface, the morphology of which was systematically altered using a relatively new technique called electrostatic-manipulation scanning tunneling microscopy. Transfor...

In the last few years scanning probe microscopy techniques have gained significant importance in a variety of different research fields in science and technology. A rapid development, stimulated by the invention of the scanning tunneling microscope in 1981 and still proceeding at a high pace, has brought about a number of new techniques belonging to this group of surface analytical methods. The...