Controlled graphene oxide assembly on silver nanocube monolayers for SERS detection: dependence on nanocube packing procedure

• Martina Banchelli,
• Bruno Tiribilli,
• Roberto Pini,
• Luigi Dei,
• Paolo Matteini and
• Gabriella Caminati

Beilstein J. Nanotechnol. 2016, 7, 9–21, doi:10.3762/bjnano.7.2

• in two orthogonal electron oscillations with respect to the surface plane when a strong near-field interaction between AgNPs occurs in the 2D array. The cubic geometry of the nanoparticles provides a large nanoparticle–substrate contact area, leading to efficient hybridization of dipolar (D) and

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

• tunneling between the Ag electrodes can also be considered as a source for background conduction [35]. We speculate that the different response of the background and the Kondo conductance to junction elongation (Figure 2c,d) comes from the different response of the orbital hybridization at the metal

Fabrication of hybrid graphene oxide/polyelectrolyte capsules by means of layer-by-layer assembly on erythrocyte cell templates

• Joseba Irigoyen,
• Nikolaos Politakos,
• Eleftheria Diamanti,
• Elena Rojas,
• Marco Marradi,
• Raquel Ledezma,
• Layza Arizmendi,
• J. Alberto Rodríguez,
• Ronald F. Ziolo and
• Sergio E. Moya

Beilstein J. Nanotechnol. 2015, 6, 2310–2318, doi:10.3762/bjnano.6.237

• ), which forms super strong sheets of carbon a single atom thick [8], result from its planar nature and the sp2 hybridization of its carbon atoms. Single layer, bi- and few-layer graphene are difficult to work with in soft matter or wet chemical applications because of dispersibility issues and the

Plasma fluorination of vertically aligned carbon nanotubes: functionalization and thermal stability

• Claudia Struzzi,
• Mattia Scardamaglia,
• Axel Hemberg,
• Luca Petaccia,
• Jean-François Colomer,
• Rony Snyders and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2015, 6, 2263–2271, doi:10.3762/bjnano.6.232

• chamber, mainly as water vapor, is also grafted on the CNTs surface in addition to fluorine species leading to oxyfluorination of the vCNTs. The fluorine functionalization causes the hybridization change from sp2 to sp3 of the carbon atoms. We show that controlled thermal heating of the sample allows for

• associated to the A1g-mode breathing vibrations of six-membered sp2 carbon rings. It becomes Raman active after neighboring sp2 carbons are converted to sp3 hybridization in graphitic materials. This can be due to the presence of in-plane substitutional heteroatom vacancies, grain boundaries, or other

• by the energetic ions during the plasma process. The grafted fluorine and oxygen atoms caused the hybridization change from sp2 to sp3 of carbon atoms. The evolution of the Raman D-band intensity showed an increase in the disorder due to the functionalization. This is presumably a consequence of tip

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

• contributions from the non-equivalent C atoms provide evidence of the molecular orbital filling, hybridization, and interchange induced by distortion. The alteration of the C–C bond lengths due to the V-shaped bending decreases by a factor of two the azimuthal dichroism of NEXAFS spectra, i.e., the energy

• , which increases by 0.07 Å from g to B. Such an elongation occurs because the C1 orbital modifies from sp2 to sp3 hybridization, which results in a displacement of the valence electron density of C1 from the C1–C2 bond to the newly formed C1–Al bond, as recently discussed for self-assembled monolayers

• reduction in the HOMO–LUMO gap of the free V-shaped molecule by 0.5 eV which decreases further for adsorption at the B site due to electron transfer. Upon adsorption, these states broaden and spread as a result of the substantial hybridization with the Al surface states. In particular for the LUMO an

Thermoelectricity in molecular junctions with harmonic and anharmonic modes

• Bijay Kumar Agarwalla,
• Jian-Hua Jiang and
• Dvira Segal

Beilstein J. Nanotechnol. 2015, 6, 2129–2139, doi:10.3762/bjnano.6.218

• thermopower, a linear response quantity, also referred to as the Seebeck coefficient, is utilized as an independent tool for probing the energetics of molecular junctions [17][18][19][20][21][22][23][24]. Experimental efforts identified orbital hybridization, contact-molecule energy coupling and geometry, and

• merit are identical. Figure 2 displays transport coefficients as a function of metal–molecule hybridization assuming a resonance situation kBT > ε0. The conductances show a turnover behavior in accord with Equation 11, growing with Γ for small values Γ < ε0, then falling down approximately as . The

• hybridization we approach the bounds ηmax/ηC→ 1, η(Pmax)/ηC→ 1/2 [46]. Particularly, for Γ≈ 0.01 eV we obtain ηmax/ηC = 0.8 at the energy ε0 = 0.15. Nonlinear performance Nonlinear thermoelectric phenomena are anticipated to enhance thermoelectric response [49]. Elastic scattering theories of nonlinear

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

• lower for PhS than for PhO for the same tip height. This difference is due to different binding patterns to the Cu(110) surface (Figure 5c,d). For PhS the sp3 hybridization of the S-atom results in a rather perfect tetrahedral bonding motif with the Cu–S–C bond angle being 111° (h = 13.9 Å). In the case

• of PhO, the sp3 hybridization of the O-atom is more distorted and the corresponding Cu–O–C bond angle is found to be 135° (h = 13.9 Å). Our transport simulations for the PhO and PhS junctions are summarized in Figure 6. The low-bias conductance is obtained from the Landauer formula, G = G0T(EF

• ascribed to a stronger hybridization with the substrate states as revealed by the increased projected density of states (PDOS) onto the chalcogen atom near EF (Figure 6b,d; more extended atomic orbitals of S than of O) as well as by the larger width of the lowest unoccupied molecular orbital (LUMO

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

• the best candidates for changing the hexagon structure of graphene with acceptable C–C distances and angles for sp2 hybridization [7]. These defects play a remarkable role in graphene and nano-structured devices. One controlled defect in graphene are grain boundaries. The electrical and thermal

• channel, which contains a 5–8–5 extended line defect in the center of the armchair graphene nanoribbon. The C–C bond lengths in the line defect are between 1.43–1.83 Å, that indicating sp2 hybridization [18]. The tight-binding model with the first nearest-neighbor approximation was used to model the

Nitrogen-doped graphene films from chemical vapor deposition of pyridine: influence of process parameters on the electrical and optical properties

• Andrea Capasso,
• Theodoros Dikonimos,
• Francesca Sarto,
• Alessio Tamburrano,
• Giovanni De Bellis,
• Maria Sabrina Sarto,
• Giuliana Faggio,
• Angela Malara,
• Giacomo Messina and
• Nicola Lisi

Beilstein J. Nanotechnol. 2015, 6, 2028–2038, doi:10.3762/bjnano.6.206

• ’ intensity ratio can be used experimentally to get information about the nature of defects in graphene [42]. The ID/ID’ ratio is found to be maximal (about 13) for defects associated with sp3 hybridization. It decreases for vacancy-like defects (about 7), and reaches a minimum for boundary-like defects

Electrical properties and mechanical stability of anchoring groups for single-molecule electronics

• Riccardo Frisenda,
• Simge Tarkuç,
• Elena Galán,
• Mickael L. Perrin,
• Rienk Eelkema,
• Ferdinand C. Grozema and
• Herre S. J. van der Zant

Beilstein J. Nanotechnol. 2015, 6, 1558–1567, doi:10.3762/bjnano.6.159

• molecule and metal [8][9][10][11][12][13][14][15][16][17][18][19][20][21]. Especially important are the alignment of the frontier orbitals to the metal Fermi level and the hybridization of these orbitals with states in the metallic electrodes [22][23][24][25]. A mechanically stable contact and strong

Possibilities and limitations of advanced transmission electron microscopy for carbon-based nanomaterials

• Xiaoxing Ke,
• Carla Bittencourt and
• Gustaaf Van Tendeloo

Beilstein J. Nanotechnol. 2015, 6, 1541–1557, doi:10.3762/bjnano.6.158

• diamond is also shown here [93] as an example of carbon nanostructure with predominantly sp3 hybridization (Figure 6e). A unique σ* feature starting at 290 eV is typical for diamond, in contrast to that of graphene, which starts at 292 eV. One step further, the doping of elements into carbon lattices can

DNA–melamine hybrid molecules: from self-assembly to nanostructures

• Rina Kumari,
• Shib Shankar Banerjee,
• Anil K. Bhowmick and
• Prolay Das

Beilstein J. Nanotechnol. 2015, 6, 1432–1438, doi:10.3762/bjnano.6.148

• hybridization. Following self-assembly, two distinct types of nanostructures in the form of linear chains and network arrays were observed. The morphology of the self-assembled nanostructures was found to depend on the number of DNA strands that were attached to a single melamine molecule. Keywords: DNA

• an attractive molecular scaffold for the precise positioning of different molecules on the nanoscale [3][4]. DNA has been used to create nanostructures through hybridization-mediated self-assembly for molecular electronics and sensing applications [5][6][7]. DNA–organic hybrid structures have

• the corresponding di-branched hybrid with complementary DNA sequence ((R2)2–melamine) by annealing in sodium phosphate buffer at pH 7.0. This self-assembly through DNA hybridization is hypothesized to yield a linear chain of the DNA–melamine hybrid. Similarly, one of the tri-branched conjugates ((R1)3

Natural and artificial binders of polyriboadenylic acid and their effect on RNA structure

• Giovanni N. Roviello,
• Domenica Musumeci,
• Valentina Roviello,
• Marina Pirtskhalava,
• Alexander Egoyan and
• Merab Mirtskhulava

Beilstein J. Nanotechnol. 2015, 6, 1338–1347, doi:10.3762/bjnano.6.138

• proteins in the cell, thus leading to new therapeutic strategies based on poly(rA) binders [15]. Interestingly, nuclear endogenous poly(rA) was tagged in living cells using fluorescently labelled oligo(dT) as a hybridization probe to study the movement of RNA through the interchromatin space [16

High photocatalytic activity of V-doped SrTiO₃ porous nanofibers produced from a combined electrospinning and thermal diffusion process

• Panpan Jing,
• Wei Lan,
• Qing Su and
• Erqing Xie

Beilstein J. Nanotechnol. 2015, 6, 1281–1286, doi:10.3762/bjnano.6.132

• of SrTiO3. Previous works showed that doping with 3d (V, Fe, Ni) and 4f (Nd, Sm, Er) ions can significantly decrease the band gap through the hybridization of the Ti-3d and dopant-d states [16][17]. Additionally, the doped SrTiO3 also has an improved conductivity. Several groups have reported the

Can molecular projected density of states (PDOS) be systematically used in electronic conductance analysis?

• Tonatiuh Rangel,
• Gian-Marco Rignanese and
• Valerio Olevano

Beilstein J. Nanotechnol. 2015, 6, 1247–1259, doi:10.3762/bjnano.6.128

• because the metal–molecule charge transfer is not the only, or the main, parameter affecting the electronic structure of BDT-p. This might be due to a possibly higher metal–molecule coupling and hybridization. In conclusion, Method 3 provides encouraging partially satisfactory results, in particular in

• reconciling the two traditional methods as in BDT-h. However, this is not the case in general, and not all problems are solved. The metal–molecule charge transfer is not the only mechanism at play. One should probably also take into account the metal–molecule hybridization. This is not an easy task if the

• questionable. We should first provide an answer to the following fundamental questions: Which set of MOs physically represent the molecule in the junction? Given the lead–molecule hybridization, are the MOs obtained from an isolated molecule (i.e., from Methods 1 or 3) meaningful for analysis of a metal

Applications of three-dimensional carbon nanotube networks

• Manuela Scarselli,
• Paola Castrucci,
• Francesco De Nicola,
• Ilaria Cacciotti,
• Francesca Nanni,
• Emanuela Gatto,
• Mariano Venanzi and
• Maurizio De Crescenzi

Beilstein J. Nanotechnol. 2015, 6, 792–798, doi:10.3762/bjnano.6.82

• studies described in [13]. SEM micrographs obtained at higher magnification evidence the presence of interconnected and curled CNTs as shown in Figure 2b. The electron energy loss spectroscopy analysis performed in reflection mode further supports the predominance of C-sp2 hybridization in the nanotubes

Chains of carbon atoms: A vision or a new nanomaterial?

• Florian Banhart

Beilstein J. Nanotechnol. 2015, 6, 559–569, doi:10.3762/bjnano.6.58

• . Keywords: atom chains; carbon; carbyne; one-dimensional solids; sp1 hybridization; Introduction Carbon is a unique element due to its ability to form bonds in three different hybridizations. The hybridizations, sp1, sp2, and sp3, correspond to bonding geometries in one-, two-, and three-dimensional space

• of states in the contacting material at low energy is small. Another aspect is the local hybridization of the carbon atoms at the contact. A sp3-hybridized carbon atom (e.g., when the chain is connected to the middle of a graphenic sheet or the wall of a carbon nanotube as shown in Figure 5) leads to

• of 0.6 eV. In the lowest energy configuration the chains would have cross-links every 2.2 nm (17 atoms) [19]. The formation of such cross-links, where local sp2 hybridization occurs, is considered as the mechanism of degradation of carbyne [62]. An important question is whether isolated chains have a

Silica micro/nanospheres for theranostics: from bimodal MRI and fluorescent imaging probes to cancer therapy

• Shanka Walia and
• Amitabha Acharya

Beilstein J. Nanotechnol. 2015, 6, 546–558, doi:10.3762/bjnano.6.57

• tremendous attention among the researchers in the field of rare-earth-doped NPs for multicolor phosphor applications. The extraordinary enhancement in the luminescent property (ca. 5–6 times of the initial value) of these nanoscale materials was associated with the hybridization of the electronic structure

Raman spectroscopy as a tool to investigate the structure and electronic properties of carbon-atom wires

• Alberto Milani,
• Matteo Tommasini,
• Valeria Russo,
• Andrea Li Bassi,
• Andrea Lucotti,
• Franco Cataldo and
• Carlo S. Casari

Beilstein J. Nanotechnol. 2015, 6, 480–491, doi:10.3762/bjnano.6.49

• based on sp2 hybridization of carbon atoms, sp-hybridized carbon-atom wires (CAWs) are intriguing systems with structure-, length- and termination-dependent properties [5]. Similar to graphene (which today is considered the ultimate 2D system (1-atom-thick)), CAWs represent a true 1D system (1-atom

• information on their structure, hybridization state, defects, presence of functionalization and/or doping, and can even quantify the nanotube chirality, the number of layers and the edge structure in graphene [22][23]. In this review we discuss how Raman spectroscopy can be utilized to obtain a wealth of

• Peierls distortion effects [73]. Examples of the extreme sensitivity of Raman spectroscopy to the carbon hybridization state, electronic structure and local order, are shown in Figure 3, where different carbon systems are characterized by well-defined Raman scattering features. In contrast to the other

Overview about the localization of nanoparticles in tissue and cellular context by different imaging techniques

• Anja Ostrowski,
• Daniel Nordmeyer,
• Alexander Boreham,
• Cornelia Holzhausen,
• Lars Mundhenk,
• Christina Graf,
• Martina C. Meinke,
• Annika Vogt,
• Sabrina Hadam,
• Jürgen Lademann,
• Eckart Rühl,
• Ulrike Alexiev and
• Achim D. Gruber

Beilstein J. Nanotechnol. 2015, 6, 263–280, doi:10.3762/bjnano.6.25

• microscope (0.2 µm) and the grain size of the emulsion [69]. This technique has previously been used, for example, for the localization of specific nucleic acid sequence, e.g., chromosomes or viral infections, by in situ hybridization employing radiolabeled nucleic acid probes [70]. We reasoned that this

X-ray photoelectron spectroscopy of graphitic carbon nanomaterials doped with heteroatoms

• Toma Susi,
• Thomas Pichler and
• Paola Ayala

Beilstein J. Nanotechnol. 2015, 6, 177–192, doi:10.3762/bjnano.6.17

• unique nature of sp2 hybridization [9], strong σ bonds are formed between carbon atoms in fullerenes, nanotubes and graphene (Figure 1), along with delocalized π orbitals [10]. These materials each have superb intrinsic properties. Fullerenes are very stable nanocontainers [11], exhibiting interesting

• expected for different systems, and values reported for graphene often tend to be in the higher end of the range. This may be due to the influence of hybridization between the valence orbitals of N with the underlying substrate [32], which reduces core hole screening and thus raises the binding energy, or

Exploring plasmonic coupling in hole-cap arrays

• Thomas M. Schmidt,
• Maj Frederiksen,
• Vladimir Bochenkov and
• Duncan S. Sutherland

Beilstein J. Nanotechnol. 2015, 6, 1–10, doi:10.3762/bjnano.6.1

• . The interesting and complex coupling between caps and hole arrays reveals the details of the field distribution for these simple to fabricate structures. Keywords: caps; colloidal lithography; hybridization; localized surface plasmon resonance; near field; SRO hole arrays; Introduction The

• explained by the hybridization model which describes the complex plasmonic interactions as a combination of elementary plasmon modes [17]. Good examples of this are seen in the cases of nanorice [4], nanostars [18], semishells [8] and nanoparticle dimers [19][20]. Such hybridized systems have shown promise

• the optical properties of short range ordered arrays of nanocap-holes coupled structures and interpret them in terms of hybridization of their more elementary components. We fabricate these structures utilizing colloidal monolayer masks as a template and compare experimental extinction data to finite

Spectroscopic mapping and selective electronic tuning of molecular orbitals in phosphorescent organometallic complexes – a new strategy for OLED materials

• Pascal R. Ewen,
• Jan Sanning,
• Tobias Koch,
• Nikos L. Doltsinis,
• Cristian A. Strassert and
• Daniel Wegner

Beilstein J. Nanotechnol. 2014, 5, 2248–2258, doi:10.3762/bjnano.5.234

• orbitals of Pt(II) complexes adsorbed on Au(111). The analysis showed that the molecules exhibit a peculiar localized strong hybridization that leads to partial depopulation of a dz² orbital, while the ligand orbitals are almost unchanged. We further found that substitution of functional groups at well

• transfer; density-functional theory; frontier orbitals; hybridization; OLED; Pt(II) complex; scanning tunneling microscopy; scanning tunneling spectroscopy; triplet emitters; Introduction Organic light emitting diodes (OLEDs) based on phosphorescent Ir(III) or Pt(II) complexes (also referred to as triplet

• (e.g., host–guest interactions, hybridization at surfaces and interfaces, interaction in aggregates) can significantly change the energetic position and order of molecular orbitals, but CV cannot always provide information on such effects whenever the local environment is not well known. Moreover, CV

Two-dimensional and tubular structures of misfit compounds: Structural and electronic properties

• Tommy Lorenz,
• Jan-Ole Joswig and
• Gotthard Seifert

Beilstein J. Nanotechnol. 2014, 5, 2171–2178, doi:10.3762/bjnano.5.226

• structures and Si–O–Si bond angles of 140°. In this system, a real covalent bond between the two subsystems can be observed, which partly changes the hybridization of the carbon atoms from sp2 to sp3. Conclusion In this review, the structures of misfit layer compounds were discussed. As was illustrated, MLCs

Effect of channel length on the electrical response of carbon nanotube field-effect transistors to deoxyribonucleic acid hybridization

• Hari Krishna Salila Vijayalal Mohan,
• Jianing An,
• Yani Zhang,
• Chee How Wong and
• Lianxi Zheng

Beilstein J. Nanotechnol. 2014, 5, 2081–2091, doi:10.3762/bjnano.5.217

• .5.217 Abstract A single-walled carbon nanotube (SWCNT) in a field-effect transistor (FET) configuration provides an ideal electronic path for label-free detection of nucleic acid hybridization. The simultaneous influence of more than one response mechanism in hybridization detection causes a variation

• in electrical parameters such as conductance, transconductance, threshold voltage and hysteresis gap. The channel length (L) dependence of each of these parameters necessitates the need to include them when interpreting the effect of L on the response to hybridization. Using the definitions of

• intrinsic effective mobility (µe) and device field-effect mobility (µf), two new parameters were defined to interpret the effect of L on the FET response to hybridization. Our results indicate that FETs with ≈300 µm long SWCNT exhibited the most appreciable response to hybridization, which complied with the