Chemiresistive/SERS dual sensor based on densely packed gold nanoparticles

• Sanda Boca,
• Cosmin Leordean,
• Simion Astilean and
• Cosmin Farcau

Beilstein J. Nanotechnol. 2015, 6, 2498–2503, doi:10.3762/bjnano.6.259

• cross-linked nanoparticle films [6][14]. The effective permittivity in the environment of the nanoparticles can increase due to the adsorption of analytes, which can replace ligands or fill up inter-molecular voids on the surface of the nanoparticles. This can decrease the activation energy for electron

• transfer, which is in turn observed as a resistance decrease. Moreover, in our system MBA is a thiol-terminated molecule while folic acid is not, and therefore one can expect that the MBA molecules can replace folic acid ligands from the surface of the gold particles. MBA is smaller than folic acid, and

Green and energy-efficient methods for the production of metallic nanoparticles

• Mitra Naghdi,
• Mehrdad Taheran,
• Satinder K. Brar,
• M. Verma,
• R. Y. Surampalli and
• J. R. Valero

Beilstein J. Nanotechnol. 2015, 6, 2354–2376, doi:10.3762/bjnano.6.243

• candidates for homogeneous-phase electron transfer processes [150][151]. POMs can be used in synthesis of metallic NPs, since their solubility in water and capability for participating in multi-electron redox reactions without structural changes [152]. Zhang et al. studied the capability of the mixed-valence

Self-organization of gold nanoparticles on silanated surfaces

• Htet H. Kyaw,
• Salim H. Al-Harthi,
• Azzouz Sellai and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2015, 6, 2345–2353, doi:10.3762/bjnano.6.242

• glass surface. Due to the electron transfer from AuNPs to APTES molecules, slight binding energy shift with higher intensity of propyl chain (from 10.6 eV to 11 eV) can be observed upon the deposition of AuNPs on APTES-functionalized glass substrate (Figure 5a) . However, the amine peak of APTES at 4.8

Green synthesis, characterization and catalytic activity of natural bentonite-supported copper nanoparticles for the solvent-free synthesis of 1-substituted 1H-1,2,3,4-tetrazoles and reduction of 4-nitrophenol

• Akbar Rostami-Vartooni,
• Mohammad Alizadeh and
• Mojtaba Bagherzadeh

Beilstein J. Nanotechnol. 2015, 6, 2300–2309, doi:10.3762/bjnano.6.236

• onto the Cu surface; followed by electron transfer from the BH4− to 4-NP; and finally, desorption of the generated 4-aminophenol from the surface of the catalyst [37][38]. Since catalysis takes place on the Cu surface, Cu NPs/bentonite are much more reactive than the unmodified natural bentonite

Influence of wide band gap oxide substrates on the photoelectrochemical properties and structural disorder of CdS nanoparticles grown by the successive ionic layer adsorption and reaction (SILAR) method

• Mikalai V. Malashchonak,
• Alexander V. Mazanik,
• Olga V. Korolik,
• Еugene А. Streltsov and
• Anatoly I. Kulak

Beilstein J. Nanotechnol. 2015, 6, 2252–2262, doi:10.3762/bjnano.6.231

• substrate, ensuring improved electron transfer from the NPs to the oxide matrix. For all types of WBGO substrates the dependence of IPCE (Y) on the number of SILAR cycles passes through a maximum (Figure 2d). The increase in IPCE in the range of small N is naturally related to the increase in optical

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

• due to the interfacial electron transfer. In our recent work [15], we studied experimentally and theoretically the adsorption of pentacene on the Al(001) substrate. We performed simulations including the long range vdW interactions and without them. In the latter case we observed that the bonding

• density depletion in the close proximity of the C–Al bond, with overall electron transfer from the surface to pentacene. An excess electronic charge of ΔQ = 0.56e is calculated on the adsorbed molecule, by means of Löwdin charge partitioning scheme [29][30]. One also observes (see the red regions in

• 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

• , constructing the “anharmonic” (AH) mode model. In a different context, the AH model could represent transport through molecular magnets, in which electron transfer is controlled by a spin impurity [37]. The complete information over transport behavior is contained in the respective cumulant generating

• Figure 6b. Discussion and Prospect We focused on two-site electronic junctions in which electron transfer between sites is assisted by a particular mode, harmonic or anharmonic (two-state system). The complete information over steady state transport behavior is catered by the cumulant generating function

• nontrivial order) in the electron phonon coupling g. This is evident from the structure of the rate constants in Equation 10, as electron transfer is facilitated by the absorption/emission of a single quantum ω0. In numerical simulations we typically employed g = 0.01 eV and ω0 = 0.02 eV. This value for g

Electrochemical behavior of polypyrrol/AuNP composites deposited by different electrochemical methods: sensing properties towards catechol

• Celia García-Hernández,
• Cristina García-Cabezón,
• Cristina Medina-Plaza,
• Fernando Martín-Pedrosa,
• Yolanda Blanco,
• José Antonio de Saja and
• María Luz Rodríguez-Méndez

Beilstein J. Nanotechnol. 2015, 6, 2052–2061, doi:10.3762/bjnano.6.209

• cogeneration) was not so important. The limits of detection (LOD) were in the range from 10−5 to 10−6 mol/L. LODs attained using films deposited on platinum were lower due to a synergy between AuNPs and platinum that facilitates the electron transfer, improving the electrocatalytic properties. Such synergistic

• ) the semicircular part is associated to electron-transfer limited processes. The diameter of the semicircle is equivalent to the electron-transfer resistance (Rct). The linear part that appears at lower frequencies is related to diffusion limited processes. In the case of Ppy deposited by CA, the

• Nyquist plot (Figure 3a) was a semicircle (Rct, 45.54 kΩ). The electrochemical process was thus, dominated by electron transfer. The insertion of AuNPs in the Ppy films clearly modified the electrical behavior. In effect, the Nyquist plot of Ppy/AuNP-T-CAPt films obtained by trapping (Figure 3b) showed a

Effect of SiN_x diffusion barrier thickness on the structural properties and photocatalytic activity of TiO₂ films obtained by sol–gel dip coating and reactive magnetron sputtering

• Mohamed Nawfal Ghazzal,
• Eric Aubry,
• Nouari Chaoui and
• Didier Robert

Beilstein J. Nanotechnol. 2015, 6, 2039–2045, doi:10.3762/bjnano.6.207

• increasing the SiNx diffusion barrier thickness affects the interfacial electron transfer rate [20]. The photo-generated electron–hole pair produced in the bulk of the photocatalyst during the illumination diffuses faster to reach the surface, since the distance traveled is reduced by the smaller crystallite

Optimized design of a nanostructured SPCE-based multipurpose biosensing platform formed by ferrocene-tethered electrochemically-deposited cauliflower-shaped gold nanoparticles

• Wicem Argoubi,
• Maroua Saadaoui,
• Sami Ben Aoun and
• Noureddine Raouafi

Beilstein J. Nanotechnol. 2015, 6, 1840–1852, doi:10.3762/bjnano.6.187

• applications [6][7][8]. Enhancement of their detection capabilities can be easily achieved by modification with various types of nanomaterials to improve the electron-transfer rates between the redox center and the electrode and to procure catalytic effects which allow them in fine to reach the very low

• through a ethylenediamine spacer was prepared by Fan et al. and used as an efficient electron transfer (ET) shuttle to build a sensor for H2O2 [16]. Also, a nanocomposite formed with ferrocene-branched silica material reduced graphene oxide and glucose oxidase entrapped in chitosan matrix and was used for

• 4-fold increase of the surface resistivity because of the total passivation of the gold surface by a sulfur layer. Further modification with the antibody and BSA increases the surface impedance due to the electron transfer from the redox probe present in the solution. Thus, the ferrocene covered by

Conductance through single biphenyl molecules: symmetric and asymmetric coupling to electrodes

• Karthiga Kanthasamy and
• Herbert Pfnür

Beilstein J. Nanotechnol. 2015, 6, 1690–1697, doi:10.3762/bjnano.6.171

• the metal–molecule bonds, characterized by, e.g., the electron transfer, cannot be altered. Therefore, changes of bond angles [20][38], perhaps coupled with configurational changes at the metal electrodes, seem to be the most likely reason. Perhaps the most surprising result of this study is the high

Scalable, high performance, enzymatic cathodes based on nanoimprint lithography

• Dmitry Pankratov,
• Richard Sundberg,
• Javier Sotres,
• Dmitry B. Suyatin,
• Ivan Maximov,
• Sergey Shleev and
• Lars Montelius

Beilstein J. Nanotechnol. 2015, 6, 1377–1384, doi:10.3762/bjnano.6.142

• : bilirubin oxidase; bio-electrocatalysis; direct electron transfer; nanoimprint lithography; oxygen reduction reaction; Introduction Reduction of oxygen (O2) is the key reaction in many natural and artificial systems, and indeed, this reaction is one of the most interesting research issues in both academia

• , especially multicopper oxidases (MCOs) [2][3]. In nature, MCOs catalyse the oxidation of many organic and inorganic compounds (electron donors) using O2 as the only electron acceptor [4]. The O2 bio-electroreduction mechanism involves electron transfer from the electrode to the T1 copper (Cu) site with the

• commercially available MCO, bilirubin oxidase (BOx), which is one of the main biocatalysts exploited today to design third-generation (i.e., direct electron-transfer-based), O2 reducing biodevices (e.g., O2-sensitive biosensors [18] and biocathodes of enzymatic fuel cells [19]). Contrary to many other MCOs

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

• distribution. The pore size and diameter distributions were measured to be about 10–32 nm and 90–240 nm, respectively. Such a long fibrous and porous structure is beneficial to electron transfer, dye molecular absorption and the light utilization efficiency for a photocatalyst. In Figure 1b, the morphological

Charge carrier mobility and electronic properties of Al(Op)₃: impact of excimer formation

• Andrea Magri,
• Pascal Friederich,
• Bernhard Schäfer,
• Valeria Fattori,
• Xiangnan Sun,
• Timo Strunk,
• Velimir Meded,
• Luis E. Hueso,
• Wolfgang Wenzel and
• Mario Ruben

Beilstein J. Nanotechnol. 2015, 6, 1107–1115, doi:10.3762/bjnano.6.112

• absorption spectrum. In experiment, the IP and the EA are referred to as the HOMO and LUMO energy levels of the molecule, respectively [15][24]. The cathodic cyclic voltammetry of Al(Op)3, shown in Figure 2, is characterized by three, quasi-reversible, single-electron transfer processes at −1.63, −1.84 and

From lithium to sodium: cell chemistry of room temperature sodium–air and sodium–sulfur batteries

• Philipp Adelhelm,
• Pascal Hartmann,
• Conrad L. Bender,
• Martin Busche,
• Christine Eufinger and
• Juergen Janek

Beilstein J. Nanotechnol. 2015, 6, 1016–1055, doi:10.3762/bjnano.6.105

• one-electron transfer per formula unit. In this process, the de-/intercalation of one Li-ion is linked to a change in the transition metal oxidation state by one (Co3+/4+, Fe2+/3+, Mn3+/4+, etc.), as illustrated in Figure 2a. However, since the positive electrode materials often suffer from stability

• , but all metal–oxygen batteries are superior compared to Li-ion batteries in terms of theoretical energy capacity. This is also the case for cells with NaO2 as a discharge product, although they are based on one-electron transfer. It is important to note that all values in Table 1 are theoretical

• crystallites (compare Figure 7 with Figure 11). The cells showed only very small combined overpotentials of about 200 mV during cycling which was attributed to the kinetically favored one-electron transfer. Shortly after, similar findings were reported for potassium–oxygen cells. Here, KO2 forms during

Multiscale modeling of lithium ion batteries: thermal aspects

• Arnulf Latz and
• Jochen Zausch

Beilstein J. Nanotechnol. 2015, 6, 987–1007, doi:10.3762/bjnano.6.102

• ] would lead to an additional electrical current due to electron transfer between active particles and electrolyte. With the normal n pointing from the solid into the electrolyte we obtain Thermal interface conditions Under isothermal conditions, the values of the concentrations and potentials of the

Protein corona – from molecular adsorption to physiological complexity

• Lennart Treuel,
• Dominic Docter,
• Michael Maskos and
• Roland H. Stauber

Beilstein J. Nanotechnol. 2015, 6, 857–873, doi:10.3762/bjnano.6.88

• ]. A recent theoretical study even suggests that disulfide bonds are affected by redox reactions without electron transfer [37]. A further prominent example of NP-associated catalytic activity are iron-catalyzed reactions such as the Fenton reaction [39] and others [10][11] that have been widely

Tm-doped TiO₂ and Tm₂Ti₂O₇ pyrochlore nanoparticles: enhancing the photocatalytic activity of rutile with a pyrochlore phase

• Desiré M. De los Santos,
• Javier Navas,
• Teresa Aguilar,
• Antonio Sánchez-Coronilla,
• Concha Fernández-Lorenzo,
• Rodrigo Alcántara,
• Jose Carlos Piñero,
• Ginesa Blanco and
• Joaquín Martín-Calleja

Beilstein J. Nanotechnol. 2015, 6, 605–616, doi:10.3762/bjnano.6.62

• radicals play a role in degrading pollutants [45]. It is generally suggested that the rate-limiting steps of the photocatalytic reaction of semiconductors are electron–hole recombination and electron transfer from the semiconductor surface to the adsorbed oxygen molecules [45][46][47][48]. In our case, the

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

• amount than the stronger triple bonds. Therefore, strain has a considerable influence on the conductivity of chains [23][26][28][41]. Increasing strain leads to a decreasing π-electron density over the longer single bonds. This, in turn, hinders the electron transfer over the single bonds and opens the

• carbon structures, on the other hand, can be quite different, depending on a local sp2 or sp3 character at the junction. In the case of local sp3 bonding, the π-electron density would be low at the contact and make the electron transfer difficult. The measured current–voltage characteristics show, for

Palladium nanoparticles anchored to anatase TiO₂ for enhanced surface plasmon resonance-stimulated, visible-light-driven photocatalytic activity

• Kah Hon Leong,
• Hong Ye Chu,
• Shaliza Ibrahim and
• Pichiah Saravanan

Beilstein J. Nanotechnol. 2015, 6, 428–437, doi:10.3762/bjnano.6.43

• which only a minimal absorbance was detected for TiO2. Therefore, only few electrons can be excited from the VB to the CB of TiO2, which leads to a low degradation efficiency. The degradation mechanism and electron transfer is explained in Figure 10. When Pd/TiO2 is exposed to visible light, the plasmon

• % Pd/TiO2, c) 3.0 wt % Pd/TiO2 and d) 1.0 wt % Pd/TiO2. Photocatalytic degradation rates of AMX under visible light irradiation. Schematic diagram of electron transfer and degradation mechanism of AMX. Recycled photocatalytic degradation rates of AMX (0.5 wt % Pd/TiO2). The kinetics of AMX degradation

Kelvin probe force microscopy in liquid using electrochemical force microscopy

• Liam Collins,
• Stephen Jesse,
• Jason I. Kilpatrick,
• Alexander Tselev,
• M. Baris Okatan,
• Sergei V. Kalinin and
• Brian J. Rodriguez

Beilstein J. Nanotechnol. 2015, 6, 201–214, doi:10.3762/bjnano.6.19

• local concentration of ions through migration (field-driven ion transport) and diffusion (concentration-gradient-driven transport) both to and from the solid–liquid interface as well as electron transfer reactions across the interface, resulting in a broad spectrum of charge relaxation timescales (ns–s

• electrode would be beneficial for elucidating the precise bias at which electron transfer reactions are initiated. This is the subject of ongoing investigation. The time-independent response for decane suggests that KPFM in liquid is possible in ionically-inactive liquids, as was previously reported [39

Inorganic Janus particles for biomedical applications

• Isabel Schick,
• Steffen Lorenz,
• Dominik Gehrig,
• Stefan Tenzer,
• Wiebke Storck,
• Karl Fischer,
• Dennis Strand,
• Frédéric Laquai and
• Wolfgang Tremel

Beilstein J. Nanotechnol. 2014, 5, 2346–2362, doi:10.3762/bjnano.5.244

• vector q2 in the range of scattering angle 30° ≤ θ ≤ 150°. (a) Time-resolved fluorescence spectra of Au nanoparticles (green), Atto495 (orange), MnO@SiO2 (red), and Au@MnO@SiO2-Atto495 (blue) after excitation at λ = 400 nm by a 100 fs pulse indicating the absence of electron transfer between Au and MnO

Characterization of 10,12-pentacosadiynoic acid Langmuir–Blodgett monolayers and their use in metal–insulator–metal tunnel devices

• Saumya Sharma,
• Mohamad Khawaja,
• Manoj K. Ram,
• D. Yogi Goswami and
• Elias Stefanakos

Beilstein J. Nanotechnol. 2014, 5, 2240–2247, doi:10.3762/bjnano.5.233

• processes or for insight into electron transfer rates and the kinetic and thermodynamic behavior of the PDA. Such an analysis can potentially aid in the identification of suitable applications of such materials [16]. The Ni–PDA film–Ni structure was studied in order to understand the tunneling behavior in

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

• result from the filling of the t2g energy levels coming from the titanium d states. Further studies used a comparable argument for the claim of charge transfer in other misfit layer compounds. One example is the electron transfer from PbSe to NbSe2 in [(PbSe)1.14]m(NbS2)1 with m = 1–6 [36]. The

• the SnS layer was negatively charged. Although the received charge transfer is quite small (approx. 0.1 electrons per SnS2 unit) the direction of the electron transfer was perplexing, especially because this direction is unexpected because the Sn4+ system transfers electron density to the Sn2+ system

• positions in space: black atoms above the paper-plane and red ones beneath it. Adapted with permission from [3]. Copyright 1995 Elsevier. Schematic representation of the density of states of a PbSe layer (left) and a NbSe2 layer (right). The electron transfer takes place from the PbSe valance band to the

Sequence-dependent electrical response of ssDNA-decorated carbon nanotube, field-effect transistors to dopamine

• Hari Krishna Salila Vijayalal Mohan,
• Jianing An and
• Lianxi Zheng

Beilstein J. Nanotechnol. 2014, 5, 2113–2121, doi:10.3762/bjnano.5.220

• DNA hydration layer, which is reflected as the decline in channel conductance (−∆Gon/Gon) [34]. The DA protonation results in electron transfer from the DNA to the SWCNT causing a change in the electrostatic environment around the nanotube, which is responsible for the observed shift in threshold