Hydrophilic silver nanoparticles with tunable optical properties: application for the detection of heavy metals in water

• Paolo Prosposito,
• Federico Mochi,
• Erica Ciotta,
• Mauro Casalboni,
• Fabio De Matteis,
• Iole Venditti,
• Laura Fontana,
• Giovanna Testa and
• Ilaria Fratoddi

Beilstein J. Nanotechnol. 2016, 7, 1654–1661, doi:10.3762/bjnano.7.157

• ), zeta potential (ζ-potential) measurements and scanning tunneling microscopy (STM). Further, to demonstrate the environmental application of our AgNPs, we also applied them for heavy metal sensing by detecting visible color modification due to SPR spectral changes. We found that these negatively charged

• agent (not reported) was about 60 nm. The broadening of about 30 nm can be ascribed to the surface functionalization of the AgNPs with 3MPS. We characterized the AgNP-3MPS nanoparticles via STM spectroscopy. Figure 3a,b shows the morphology and the profile of the nanoparticles, respectively. We

• <2RH> = 5 ± 2 nm, in good agreement with the STM analysis. The SPR absorption was monitored as a function of the time in order to check the long term stability of the NPs. As shown in Figure 5, the solution presents the same optical spectra 15 days after the preparation, indicating that no aggregation

Scanning probe microscopy studies on the adsorption of selected molecular dyes on titania

• Jakub S. Prauzner-Bechcicki,
• Lukasz Zajac,
• Piotr Olszowski,
• Res Jöhr,
• Antoine Hinaut,
• Thilo Glatzel,
• Bartosz Such,
• Ernst Meyer and
• Marek Szymonski

Beilstein J. Nanotechnol. 2016, 7, 1642–1653, doi:10.3762/bjnano.7.156

• dianhydride (PTCDA); phtalocyanines; porphyrins; rutile; scanning probe microscopy; scanning tunneling microscopy (STM); titanium dioxide (TiO2); Introduction Today it comes as no surprise that photovoltaic devices can be made of materials other than silicon. Nanocrystalline materials accompanied by organic

• layer [52]. Of the above-mentioned porphyrin species, only 2H-TPP has been studied with STM by Lovat et al. [52]. Similar results were reported by Wang et al. [53]. The molecules adsorb with their plane parallel to the substrate when deposited at room temperature, as expected from the results of the

• NEXAFS measurements. The STM image of a single molecule exhibits two-fold symmetry [52][53]. Molecules are sitting atop the oxygen rows with a common azimuthal orientation in a saddle-shape conformation, which has been identified as the N–N axis parallel to the [001] direction. The most favoured

Advanced atomic force microscopy techniques III

• Thilo Glatzel and
• Thomas Schimmel

Beilstein J. Nanotechnol. 2016, 7, 1052–1054, doi:10.3762/bjnano.7.98

• microscopy (AFM) celebrates its 30th anniversary this year. It was presented by Binnig, Quate and Gerber in 1986 as an extension of the scanning tunneling microscope (STM) with the possibility to measure forces as small as 10−18 N [1]. Since then many different variations of the force detection method and

• . Combined AFM and STM measurements reveal related force and electronic properties [9], energy dissipation in manipulation processes can be examined via the excitation voltage needed to keep a constant amplitude of the probe oscillation [10][11], pulling forces of atomic or molecular wires can be determined

• surfaces [33], and combined STM and AFM measurements on single-layer graphene on SiC(0001) [34] have been investigated, discussed, and presented. Another combined STM-AFM study determines very accurately the probe-nanocrystal interaction potential [35]. Finally, enhanced information can also be achieved by

Noncontact atomic force microscopy III

• Mehmet Z. Baykara and
• Udo D. Schwarz

Beilstein J. Nanotechnol. 2016, 7, 946–947, doi:10.3762/bjnano.7.86

• tunneling microscopy (STM) relies on quantum mechanical tunneling of electrons to enable the atomic-resolution imaging of (semi-)conducting sample surfaces, it was the atomic force microscope (AFM) that eventually allowed for nanometer-scale imaging of sample surfaces with no limitations on electrical

Modelling of ‘sub-atomic’ contrast resulting from back-bonding on Si(111)-7×7

• Adam Sweetman,
• Samuel P. Jarvis and
• Mohammad A. Rashid

Beilstein J. Nanotechnol. 2016, 7, 937–945, doi:10.3762/bjnano.7.85

• experimental system to which we compare our results. Typically, in sub-molecular resolution imaging experiments, well defined atoms (such as Xe or Cl), or molecules (such as CO) are picked up from metal surfaces onto metal-coated tips by STM protocols [3]. In our experimental data the initial tip termination

• is likely silicon due to prior STM treatment of the tip on the clean Si(111)-7×7 surface (although the tip bulk material is tungsten). In addition, the identity of the passivating end group, which was picked up spontaneously during NC-AFM imaging of the clean surface, is not known. Although CO is a

Optical absorption signature of a self-assembled dye monolayer on graphene

• Tessnim Sghaier,
• Sylvain Le Liepvre,
• Céline Fiorini,
• Ludovic Douillard and
• Fabrice Charra

Beilstein J. Nanotechnol. 2016, 7, 862–868, doi:10.3762/bjnano.7.78

• offers opportunities for advanced optical characterizations in a transmission geometry, such as polarized variable-incidence transmission spectroscopy. In addition, the electrical conductivity of a CVD graphene monolayer is sufficiently high to apply scanning tunnelling microscopy (STM) and thus

• paper, we explore the changes in the optical transmission spectrum of an alkylated derivative of PTCDI upon its self-assembly onto a CVD graphene monolayer, and analyse the results based on STM data taken on the very same sample. Results Scanning tunnelling microscopy The self-assembly was probed on two

• graphene. The monolayer structures have been studied by STM at the solution–substrate interface. Intramolecular resolution is possible both with HOPG and graphene as substrates (Figure 2). As expected from the atomically flat surface of HOPG, this substrate produces the largest domains. It permits an

Microscopic characterization of Fe nanoparticles formed on SrTiO₃(001) and SrTiO₃(110) surfaces

• Miyoko Tanaka

Beilstein J. Nanotechnol. 2016, 7, 817–824, doi:10.3762/bjnano.7.73

• on a reconstructed STO(001) substrate and utilized them to catalyse carbon nanotubes [15]. However, since these studies image nanoparticles with STM, the exact interfacial structures, which affect the properties of the nanoparticles more than anything else, are not directly obtained. Since interface

• nanoparticles on STO(001) and STO(110) surfaces, their morphologies and arrangements are investigated by using a combined system for ultrahigh vacuum (UHV) transmission electron microscopy (TEM)/scanning tunnelling microscopy (STM). The system provides in situ observation of nanoparticles from both horizontal

• and vertical directions by combining STM plan-view observation and TEM plan-view and profile-view observations. The formation of the Fe/STO interface was achieved by depositing Fe nanoparticles on STO substrates that are annealed under UHV. The fabricated samples were transferred to the microscopes

Thermo-voltage measurements of atomic contacts at low temperature

• Ayelet Ofarim,
• Bastian Kopp,
• Thomas Möller,
• León Martin,
• Johannes Boneberg,
• Paul Leiderer and
• Elke Scheer

Beilstein J. Nanotechnol. 2016, 7, 767–775, doi:10.3762/bjnano.7.68

• ]. Experimental techniques such as scanning tunneling microscopy (STM) and the mechanically controlled break-junction (MCBJ) technique allow investigation of transport properties of atomic-scale devices [18]. Therefore, most approaches for measurements of thermo-voltage, or simultaneous measurements of

• conductance and thermo-voltage, were using STM or MCBJs techniques. When using the STM method, results are given in a statistical manner, mostly around room temperature where the junctions are short-lived and the measurements have to be performed in a transient state [7][8][10]. Therefore correlating the

• thermopower results to the electrical conductance is not possible for the individual junctions. In most STM realizations, a temperature gradient is achieved by heating the substrate, whereas the tip remains at room temperature, or vice versa. The temperature difference is then assumed to be the difference of

Rigid multipodal platforms for metal surfaces

• Michal Valášek,
• Marcin Lindner and
• Marcel Mayor

Beilstein J. Nanotechnol. 2016, 7, 374–405, doi:10.3762/bjnano.7.34

• junctions are based on either electrochemical break junctions [13][14][15] or mechanically controlled break junctions (MCBJ) [7] as well as on scanning tunneling microscopy (STM) [9][16][17]. The ultimate goal of molecular electronics is to use assemblies of molecules or even single molecules as functional

• . Furthermore, there are several advantages of utilizing of gold as metal electrode for single molecule studies. One of the most important benefits of a gold substrate is that gold forms a reasonable clean, inert and atomically flat surface suitable for STM studies, which is not prone to impurities by reaction

• reconstruction of clean Au(111). This surface morphology changes related to adsorbed molecules can be visualized by STM techniques and provided us a reliable description of the interactions between adsorbate and substrate. Not only thiols but also sulfides (R–S–R), which form weaker molecule–substrate bonds than

Case studies on the formation of chalcogenide self-assembled monolayers on surfaces and dissociative processes

• Yongfeng Tong,
• Tingming Jiang,
• Azzedine Bendounan,
• Makri Nimbegondi Kotresh Harish,
• Angelo Giglia,
• Stefan Kubsky,
• Fausto Sirotti,
• Luca Pasquali,
• Srinivasan Sampath and
• Vladimir A. Esaulov

Beilstein J. Nanotechnol. 2016, 7, 263–277, doi:10.3762/bjnano.7.24

• explored in several STM studies [81][84][85] and these are still being actively studied [82][86][87]. Although the S 2p binding energies for bulk copper sulfide are known, with a rare exception [83], there was previously not much information on CLBEs for sub-monolayer chemisorbed phases. A detailed

Synthesis and applications of carbon nanomaterials for energy generation and storage

• Marco Notarianni,
• Jinzhang Liu,
• Kristy Vernon and
• Nunzio Motta

Beilstein J. Nanotechnol. 2016, 7, 149–196, doi:10.3762/bjnano.7.17

Single-molecule magnet behavior in 2,2’-bipyrimidine-bridged dilanthanide complexes

• Wen Yu,
• Frank Schramm,
• Eufemio Moreno Pineda,
• Yanhua Lan,
• Olaf Fuhr,
• Jinjie Chen,
• Hironari Isshiki,
• Wolfgang Wernsdorfer,
• Wulf Wulfhekel and
• Mario Ruben

Beilstein J. Nanotechnol. 2016, 7, 126–137, doi:10.3762/bjnano.7.15

• ), 2; Dy(III), 3; Ho(III), 4 and Er(III), 5) has been synthesized and characterized. Sublimation of [Tb(tmhd)3]2bpm onto a Au(111) surface leads to the formation of a homogeneous film with hexagonal pattern, which was studied by scanning tunneling microscopy (STM). The bulk magnetic properties of all

• with a Perkin Elmer Spectrum GX FT-IR system spectrophotometer. Elemental analysis data were collected on an ELEMENTAR Vario Micro Cube. NMR spectra were carried out on a Bruker Ultrashield 500 PLUS spectrometer. Scanning tunneling microscopy. The STM measurements were realized with a homebuilt

• monolayer/sec for several ten second steps at a sublimation temperature of about 433 K. The pressure during deposition was ca. 2 × 10−7 mbar. After deposition, the samples were transferred to the STM chamber immediately and cooled down to 5 K. During the measurement, the sample temperature was kept at 5 K

Current-induced runaway vibrations in dehydrogenated graphene nanoribbons

• Rasmus Bjerregaard Christensen,
• Jing-Tao Lü,
• Per Hedegård and
• Mads Brandbyge

Beilstein J. Nanotechnol. 2016, 7, 68–74, doi:10.3762/bjnano.7.8

• conductance through the ribbons has been investigated using STM [5], and the signals of electron vibrations in the current have been addressed by theory [6]. When cutting graphene into one-dimensional ribbons, dangling bonds emerge at the boundary carbon atoms. If there is an electrical current passing

• shown in Figure 1a, where four hydrogen atoms have been removed on each side of the ribbon. In principle, dehydrogenation could be performed at chosen positions with an STM [28]. The same structure has been considered in our recent work, focusing on the asymmetry in phonon emission and heat distribution

Large area scanning probe microscope in ultra-high vacuum demonstrated for electrostatic force measurements on high-voltage devices

• Urs Gysin,
• Thilo Glatzel,
• Thomas Schmölzer,
• Adolf Schöner,
• Sergey Reshanov,
• Holger Bartolf and
• Ernst Meyer

Beilstein J. Nanotechnol. 2015, 6, 2485–2497, doi:10.3762/bjnano.6.258

• model indicating that the energy levels of the SiC surface consist of a filled band and an empty band, separated by a Hubbard gap of 1.6 eV. A pinning of the Fermi level was also observed by STM studies differing only by about 200 mV between p- and n-type doped SiC [54]. SiC was found to be in the

Effects of spin–orbit coupling and many-body correlations in STM transport through copper phthalocyanine

• Benjamin Siegert,
• Andrea Donarini and
• Milena Grifoni

Beilstein J. Nanotechnol. 2015, 6, 2452–2462, doi:10.3762/bjnano.6.254

• phthalocyanine; magnetotransport; spin–orbit interaction; scanning tunneling microscopy (STM); Introduction Spin–orbit interaction (SOI) can play a major role in molecular spintronics. For example, in combination with the configuration of the non-magnetic component (organic ligand), it is known to be essential

• enormous anisotropies in both spin and orbital dipole moments [9]. Furthermore, recent experimental findings for cobalt pththalocyanine in a scanning tunneling microscopy (STM) setup [10] suggest that many-body correlations play an important role in the interpretation of the transport measurements. In a

• molecule greatly helps to reduce the number of matrix elements one has to calculate in this basis. To probe both SOI-induced splittings and magnetic anisotropy, we further investigated the current characteristics of a CuPc molecule in an STM configuration similar to the experiments in [13][14]: The

High electronic couplings of single mesitylene molecular junctions

• Yuki Komoto,
• Shintaro Fujii,
• Tomoaki Nishino and
• Manabu Kiguchi

Beilstein J. Nanotechnol. 2015, 6, 2431–2437, doi:10.3762/bjnano.6.251

• electrode perpendicular to the charge transport direction and (ii) mesitylene has tilted from the perpendicular orientation. Keywords: break junction; charge transport; mesitylene; single molecular junction; scanning tunnelling microscopy (STM); Introduction Along with increasing interests in molecular

• Γ as well as ε0. Very recently Afsari et al. have investigated the single mesitylene molecular junction with a scanning tunnelling microscopy (STM)-based break junction (BJ) technique [20]. The conductance of a single mesitylene molecular junction has been founded to be approximately 0.1G0, which is

• [39]. We used the STM-BJ method [15] operating in a liquid environment where thousands of molecular junctions were repeatedly made for statistical analysis of the molecular conductance and I–V characteristics. Figure 2 shows the conductance traces and histograms during stretching processes of the

Vibration-mediated Kondo transport in molecular junctions: conductance evolution during mechanical stretching

• David Rakhmilevitch and
• Oren Tal

Beilstein J. Nanotechnol. 2015, 6, 2417–2422, doi:10.3762/bjnano.6.249

• electrodes via its nitrogen atoms with insignificant charge transfer as supported by the experimental fit to Kondo S = 1/2. This is in contrast to the CuPc adsorption configuration on a flat Ag substrate in a STM setup which leads to Kondo S = 1 [24]. The side peaks were related to a Kondo process as well

Sub-monolayer film growth of a volatile lanthanide complex on metallic surfaces

• Hironari Isshiki,
• Jinjie Chen,
• Kevin Edelmann and
• Wulf Wulfhekel

Beilstein J. Nanotechnol. 2015, 6, 2412–2416, doi:10.3762/bjnano.6.248

• devices based on single molecules. The investigation of individual molecules is crucial to understand the physics of SMMs. Scanning tunneling microscopy (STM) is one of few methods that can reveal the magnetic properties on the level of single molecules. The magnetic properties of single ions and single

• molecules of transition metals have been widely investigated with STM [3][4][5][6]. However, there are few studies on lanthanide-based SMMs with low-temperature STM [7][8] despite the variety of reports of their peculiar magnetic properties. One plausible reason is the difficulty in transferring them onto

• group metal) β-dikenonate with low-temperature STM [11]. Tris(2,2,6,6-tetramethyl-3,5-heptanedionato)lanthanide(III) (Ln(thd)3) has the simplest molecular structure among them and is highly volatile thermally stability [12][13]. In this molecule, the lanthanide(III) ion is coordinated by three β

Negative differential electrical resistance of a rotational organic nanomotor

• Hatef Sadeghi,
• Sara Sangtarash,
• Qusiy Al-Galiby,
• Rachel Sparks,
• Steven Bailey and
• Colin J. Lambert

Beilstein J. Nanotechnol. 2015, 6, 2332–2337, doi:10.3762/bjnano.6.240

• clearly visible in STM images [41], therefore facilitating experimental STM measurements. The branch extends from the central ring of the backbone and is made up of three interlinked arene compounds; the central phenyl ring is capped by aniline at one end and terminated with a fluoro-toluene derivative at

Core-level spectra and molecular deformation in adsorption: V-shaped pentacene on Al(001)

• Anu Baby,
• He Lin,
• Gian Paolo Brivio,
• Luca Floreano and
• Guido Fratesi

Beilstein J. Nanotechnol. 2015, 6, 2242–2251, doi:10.3762/bjnano.6.230

• higher adsorption energies (at least by 0.7 eV) and hence are considered unphysical. Scanning tunneling microscopy (STM) measurements showed that a large percentage of pentacene molecules adsorb with a V-shape on a reconstructed Al(001) surface with the longer axis along the [110] direction. The

Virtual reality visual feedback for hand-controlled scanning probe microscopy manipulation of single molecules

• Philipp Leinen,
• Matthew F. B. Green,
• Taner Esat,
• Christian Wagner,
• F. Stefan Tautz and
• Ruslan Temirov

Beilstein J. Nanotechnol. 2015, 6, 2148–2153, doi:10.3762/bjnano.6.220

• (PTCDA); scanning probe microscopy (SPM); scanning tunnelling microscopy (STM); single-molecule manipulation; virtual reality interface; Introduction The recently introduced scanning probe microscopy (SPM) technique of hand controlled manipulation (HCM) allows the operator of the SPM to manipulate

• commercial, combined qPlus tuning fork [4] non-contact atomic force/scanning tunnelling microscope (NC-AFM/STM) operated at 5 K under ultra-high vacuum conditions. Each extraction attempt started with positioning the tip over one of the four carboxylic oxygen atoms (marked by red circles in Figure 1) of the

• tip was stabilized, the STM current feedback loop was opened and the control over the tip position was passed to the operator. The operator contacted the molecule by moving the tip in a strictly vertical trajectory (x,y tip coordinates frozen) until a sharp jump of the I and Δf bar indicators in the

Controlled switching of single-molecule junctions by mechanical motion of a phenyl ring

• Yuya Kitaguchi,
• Satoru Habuka,
• Hiroshi Okuyama,
• Shinichiro Hatta,
• Tetsuya Aruga,
• Thomas Frederiksen,
• Magnus Paulsson and
• Hiromu Ueba

Beilstein J. Nanotechnol. 2015, 6, 2088–2095, doi:10.3762/bjnano.6.213

• (STM), we demonstrated a molecular switch made functional by the mechanical motion of a phenyl ring, which is the atomic-scale analogue of the conventional toggle switch. A phenoxy (C6H5O, PhO) molecule bonded to the Cu(110) surface was reversibly lifted (released) to (from) the STM tip while being

• . Furthermore, the electronic levels are tunable through chemical manipulation of the phenyl ring, which in turn allows us to tailor the on-state conductance. Methods As described in the previous study [12], the experiments were carried out in an ultrahigh vacuum chamber equipped with an STM operating at 4.5 K

• dehydrogenation as in the case of phenol. An electrochemically etched tungsten tip was used as an STM probe. The tips were repeatedly and gently touched to the Cu surface to coat them with copper, resulting in Cu-terminated tips for reliable switching [14]. We observed that sharp tips give high-contrast images

High I_on/I_off current ratio graphene field effect transistor: the role of line defect

• Mohammad Hadi Tajarrod and
• Hassan Rasooli Saghai

Beilstein J. Nanotechnol. 2015, 6, 2062–2068, doi:10.3762/bjnano.6.210

• conductivity decrease with grain boundaries in materials [8][9]. By studying the grain boundaries in graphite, extended line defects become visible in the STM analysis [10]. The first experimental report of the extended line defect (ELD), which was studied through alternating Stone–Thrower–Wales defects, was

Distribution of Pd clusters on ultrathin, epitaxial TiO_x films on Pt₃Ti(111)

• Christian Breinlich,
• Maria Buchholz,
• Marco Moors,
• Tobias Pertram,
• Conrad Becker and
• Klaus Wandelt

Beilstein J. Nanotechnol. 2015, 6, 2007–2014, doi:10.3762/bjnano.6.204

• Scanning tunnelling microscopy (STM) was used to investigate the nucleation and growth of palladium clusters on two different, ultrathin, epitaxial, titania films grown on a Pt3Ti(111) surface. The first oxide phase, z'-TiOx, is anisotropic and consists of parallel stripes separated by trenches. Defects

• -type superstructure with fewer and shallower defects, making the template effect less discernible. Keywords: cluster growth; palladium; platinum–titanium alloy; scanning tunnelling microscopy (STM); template; titanium oxide; Introduction Catalysts often consist of metal nanoparticles dispersed on an

• ) for the rectangular and w'-TiOx (wagon-wheel-like) for the hexagonal oxide phase, according to their appearance in STM images. Due to the similarity of our films to those described for Pt(111), we decided to simply adopt the same nomenclature throughout this paper. The rectangular z'-TiOx phase

Atomic scale interface design and characterisation

• Carla Bittencourt,
• Chris Ewels and
• Arkady V. Krasheninnikov

Beilstein J. Nanotechnol. 2015, 6, 1708–1711, doi:10.3762/bjnano.6.174

• better than 0.1 nm, in addition to elemental analysis [25]. The analysis of experimental results can significantly profit from the comparison of the images to the results of first-principles calculations. Similarly, for the precise interpretation of experimental scanning tunneling microscopy (STM) and

• simulated. An impressive example of how STM experiments and DFT calculations together can unravel the atomic structure of the material is given in the article by J. A. Lawlor and M. S. Ferreira [26] focused on the identification of dopant impurities in graphene. Synergy effects of TEM and DFT are