Tuning adhesion forces between functionalized gold colloidal nanoparticles and silicon AFM tips: role of ligands and capillary forces

• Sven Oras,
• Sergei Vlassov,
• Marta Berholts,
• Rünno Lõhmus and
• Karine Mougin

Beilstein J. Nanotechnol. 2018, 9, 660–670, doi:10.3762/bjnano.9.61

• , France Department of Physics and Astronomy, University of Turku, FIN-20014 Turku, Finland 10.3762/bjnano.9.61 Abstract Adhesion forces between functionalized gold colloidal nanoparticles (Au NPs) and scanning probe microscope silicon tips were experimentally investigated by atomic force microscopy (AFM

• ) equipped with PeakForce QNM (Quantitative Nanoscale Mechanics) module. Au NPs were synthesized by a seed-mediated process and then functionalized with thiols containing different functional groups: amino, hydroxy, methoxy, carboxy, methyl, and thiol. Adhesion measurements showed strong differences between

• either Au NPs or silicon substrates (or both) significantly and directly affects the adhesion of the particles and their mobility on the surface [19][20]. Hence, Darwich et al. have shown that the mobility of Au NPs was significantly impacted by the intermolecular interactions between an AFM tip and NPs

Mechanistic insights into plasmonic photocatalysts in utilizing visible light

• Kah Hon Leong,
• Azrina Abd Aziz,
• Lan Ching Sim,
• Pichiah Saravanan,
• Min Jang and
• Detlef Bahnemann

Beilstein J. Nanotechnol. 2018, 9, 628–648, doi:10.3762/bjnano.9.59

• of noble metal nanoparticles is significantly influenced by the LSPR frequency [17][18][19][20]. It must be noted that not all noble metal nanoparticles of 10 nm diameter are able to utilize visible light, as shown in Figure 3. Ag and Au NPs are relatively good at harvesting visible light as compared

• al. incorporated Au as a secondary noble metal in a Ag@AgBr heterostructure in which the LSPR of Au NPs remained in the visible region. The resulting bimetallic (Ag–Au) coupling boosted the photocatalytic efficiency by 16-fold as compared to mono-metallic (AgBr). The increase of the resonance-excited

• hot-electron density on the surface of Ag and Au NPs escalated the Fermi energy level of Ag and Au, enabling the electrons to be easily injected to the conduction band of AgBr. Simultaneously, the difference in work function between the bimetallic and AgBr formed a Schottky junction to facilitate the

Bombyx mori silk/titania/gold hybrid materials for photocatalytic water splitting: combining renewable raw materials with clean fuels

• Stefanie Krüger,
• Michael Schwarze,
• Otto Baumann,
• Christina Günter,
• Michael Bruns,
• Christian Kübel,
• Dorothée Vinga Szabó,
• Rafael Meinusch,
• Verónica de Zea Bermudez and
• Andreas Taubert

Beilstein J. Nanotechnol. 2018, 9, 187–204, doi:10.3762/bjnano.9.21

• reported. All materials are monoliths with diameters of up to ca. 4.5 cm. The materials are macroscopically homogeneous and porous with surface areas between 170 and 210 m2/g. The diameter of the TiO2 nanoparticles (NPs) – mainly anatase with a minor fraction of brookite – and the Au NPs are on the order

Thermo- and electro-optical properties of photonic liquid crystal fibers doped with gold nanoparticles

• Agata Siarkowska,
• Miłosz Chychłowski,
• Daniel Budaszewski,
• Bartłomiej Jankiewicz,
• Bartosz Bartosewicz and
• Tomasz R. Woliński

Beilstein J. Nanotechnol. 2017, 8, 2790–2801, doi:10.3762/bjnano.8.278

• of the response time under an external electric field. In the present research we used a 6CHBT nematic LC [19] and 4 nm diameter, spherical Au NPs (Figure 1a), both synthesized in the Military University of Technology, Warsaw, Poland. Au NPs have been used for applications both in photonics and

• result in absorption or scattering of light (Figure 1b). Depending on the size, concentration or shape of the particles, the plasmon resonance can appear at different wavelengths. Moreover, NPs can also provide different properties for the host material. For example, Au NPs have a tendency to lower the

• nematic–isotropic phase transition temperature [21][22], but with a specific surface coating, the effect can be reversed [23]. The presence of Au NPs in an LC has proven to influence the response time and lower the threshold voltage [24][25][26][27][28]. In this paper we compare four different

The role of ligands in coinage-metal nanoparticles for electronics

• Ioannis Kanelidis and
• Tobias Kraus

Beilstein J. Nanotechnol. 2017, 8, 2625–2639, doi:10.3762/bjnano.8.263

• , requires temperatures that depend on the particle size and binding strength of the ligand [44]. For example, short alkanethiols allowed for the sintering of gold nanoparticles (Au NPs) at temperatures smaller than 150 °C [45], far below the typical gold sintering temperatures of 200–350 °C [35][36]. It is

• dithiocarbamate derivatives interconnecting nanoparticles influenced film conductivities in a study by Wessels and co-workers: When the authors replaced a benzene ring in the ligand with a cyclohexane ring, the film conductivity dropped. Conjugation in the benzene ligands and their good contact to the Au NPs

• modified nanoparticles exhibited resistivities that were six and ten orders of magnitude below that of films prepared from the original oleylamine-stabilized Au NPs [102]. The commonly used CTAB forms insulating layers, too, and has limited solubility even in water that makes ink formulation challenging

Direct writing of gold nanostructures with an electron beam: On the way to pure nanostructures by combining optimized deposition with oxygen-plasma treatment

• Domagoj Belić,
• Mostafa M. Shawrav,
• Emmerich Bertagnolli and
• Heinz D. Wanzenboeck

Beilstein J. Nanotechnol. 2017, 8, 2530–2543, doi:10.3762/bjnano.8.253

• investigated the FEBID of vertical Au NPs as model structures to elucidate how the variation of the experimental parameters influenced the metal content in the NPs. The electron beam impinging on a single spot on the substrate allowed us to produce free-standing NPs of a relatively large height-to-width aspect

• Au NPs produced by FEBID in non-reactive environments [38][43]. The corresponding electron diffraction pattern given in the inset of Figure 1c is consistent with polycrystalline Au, revealing interplanar distances of (2.4 ± 0.1) Å, (2.1 ± 0.1) Å, (1.4 ± 0.1) Å, and (1.2 ± 0.1) Å that correspond to

• possibly addition of other gases), and substrate parameters (such as substrate type and temperature). To reduce the level of complexity, here we restrict the full parameter space to a subspace spanned by the axes of high tension, electron beam current, and deposition time. The deposition of Au NPs was

Evaluating the toxicity of TiO₂-based nanoparticles to Chinese hamster ovary cells and Escherichia coli: a complementary experimental and computational approach

• Alicja Mikolajczyk,
• Natalia Sizochenko,
• Ewa Mulkiewicz,
• Anna Malankowska,
• Michal Nischk,
• Przemyslaw Jurczak,
• Seishiro Hirano,
• Grzegorz Nowaczyk,
• Adriana Zaleska-Medynska,
• Jerzy Leszczynski,
• Agnieszka Gajewicz and
• Tomasz Puzyn

Beilstein J. Nanotechnol. 2017, 8, 2171–2180, doi:10.3762/bjnano.8.216

• release of ions from the TiO2 surface, the generation of reactive oxygen species (ROS) and the subsequently induced oxidative stress [4][46]. For example, according to Li et al. [4] and Qiu et al. [47], the cytotoxicity of Au NPs occurs via the generation of ROS and the peroxidation of lipids. Katsumiti

• et al. [48] found that citrate-stabilized Au NPs exhibited a relatively low cytotoxicity, being less toxic than ionic Au, but more toxic than bulk Au. Similar results have been obtained by Contreras et al. [49]. Authors indicated that Ag+ is the most toxic among various metal cations (i.e., Ag+, Cu

• the nano-QSAR model. These findings clearly demonstrate that the cytotoxicity depends on particle size and surface area, which is in line with the recent experimental results. For instance, Coradeghini et al. [50] investigated the particle size dependent cytotoxicity of Au NPs (0.8–15 nm) to four

Methionine-mediated synthesis of magnetic nanoparticles and functionalization with gold quantum dots for theranostic applications

• Arūnas Jagminas,
• Agnė Mikalauskaitė,
• Vitalijus Karabanovas and
• Jūrate Vaičiūnienė

Beilstein J. Nanotechnol. 2017, 8, 1734–1741, doi:10.3762/bjnano.8.174

• , although some of them seemed to be spherical with a diameter of ca. 2.0 nm. More precise results were obtained by the determination of the size of gold species that were removed from the NP surface by the ultrasonic agitation of 10 mg CoFe2O4@Met/Au NPs probe in 10 mmol·L−1 methionine solution. As a result

• a reddish-pink solution was obtained after 20 min processing (see inset in Figure 3). This process is most likely due to the stronger capping of Au NPs with methionine molecules than with CoFe2O4@Met/Au NPs. Note that no fluorescence was seen under UV and blue-light excitation of this solution

• cobalt ferrite NPs was also investigated using X-ray photoelectron spectroscopy (XPS). The surface chemical composition of the CoFe2O4@Met–Au NPs is presented in Table 1, whereas the typical core-level spectrum of the deposited gold is presented in Figure 5. As shown, the main Au 4f7/2 photoelectron peak

Two-dimensional carbon-based nanocomposites for photocatalytic energy generation and environmental remediation applications

• Suneel Kumar,
• Ashish Kumar,
• Ashish Bahuguna,
• Vipul Sharma and
• Venkata Krishnan

Beilstein J. Nanotechnol. 2017, 8, 1571–1600, doi:10.3762/bjnano.8.159

Gas sensing properties of MWCNT layers electrochemically decorated with Au and Pd nanoparticles

• Elena Dilonardo,
• Michele Penza,
• Marco Alvisi,
• Riccardo Rossi,
• Gennaro Cassano,
• Cinzia Di Franco,
• Francesco Palmisano,
• Luisa Torsi and
• Nicola Cioffi

Beilstein J. Nanotechnol. 2017, 8, 592–603, doi:10.3762/bjnano.8.64

• total surface amount of deposited Au NPs, and therefore, on the surface chemical composition. In this contribution, we compare the sensing performance of Pd-modified MWCNT-based chemiresistors to that of Au-modified MWCNT-based chemiresistors (already investigated in previous study [19]) towards the

• ammonium salt was used both as a supporting electrolyte and as a nanoparticle capping agent. Tetrabutylammonium bromide (TBAB) was used for Pd NP synthesis and tetraoctylammonium chloride (TOAC) for the Au NPs [35]. The electrochemically synthesized Au and Pd NPs had a uniform dispersion with a diameter of

• was used as the working electrode and the Ag/AgNO3 (0.1 M in acetonitrile) system was the reference electrode [19]. The colloidal solution, consisting of 10 mM Au NPs or Pd NPs, and 5 mM tetraalkylammonium salt in tetrahydrofurane and acetonitrile mixture in 3:1 ratio, was the electrolytic solution

Sandwich-like layer-by-layer assembly of gold nanoparticles with tunable SERS properties

• Zhicheng Liu,
• Lu Bai,
• Guizhe Zhao and
• Yaqing Liu

Beilstein J. Nanotechnol. 2016, 7, 1028–1032, doi:10.3762/bjnano.7.95

• multilayer thin films could be obtained using LbL assembly techniques via electrostatic interactions [15]. By controlling the number of deposition layers, the plasmonic properties as well as the SERS properties could be tuned easily. Moreover, Kim and co-workers showed that gold nanoparticles (Au NPs) could

• alternating the adsorption of polyethyleneimine–silver ions and Au NPs onto substrates and the subsequent in situ reduction of the silver ions [17]. Compared with the parallel samples, the bimetallic LbL film showed improved SERS properties. Although a few examples of SERS substrates based on LbL strategy

• polyelectrolyte and Au NPs [18]. The tuning of SERS intensities was realized by varying the number of deposited Au NP layer. Here, we present that SERS properties of LbL thin film could be controlled by assembling Au NPs of different sizes or changing the interlayer distance between Au NP layers. Sandwich-like

Tight junction between endothelial cells: the interaction between nanoparticles and blood vessels

• Yue Zhang and
• Wan-Xi Yang

Beilstein J. Nanotechnol. 2016, 7, 675–684, doi:10.3762/bjnano.7.60

• [40]. The same goes also for Au NPs. They can bind to red blood cells to provide great X-ray imaging of the blood flow [41], but there side effects to this such as oxidative stress and toxicity [42]. Additionally, recent studies found a close interaction of NPs with several important barriers (e.g

• the changing status of signalling pathways based on kinases. In a study using primary osteoblasts as material to evaluate the biocompatibility of 20 nm and 40 nm Au NPs, the Au NPs increased the level of ERK phosphorylation/total ERK [76]. Also, a study of potential mechanisms of Ag-NP toxicity using

• [81]. Silver and gold NPs showed their ability to interact with arginine kinase in Trypanosoma brucei by binding to the arginine substrate, which is essential in the transformation between ADP and ATP [82]. In summary, Au NPs, Ag NPs/QDs and SiO2 NPs showed the capability to interact with several

Hemolysin coregulated protein 1 as a molecular gluing unit for the assembly of nanoparticle hybrid structures

• Tuan Anh Pham,
• Andreas Schreiber,
• Elena V. Sturm (née Rosseeva),
• Stefan Schiller and
• Helmut Cölfen

Beilstein J. Nanotechnol. 2016, 7, 351–363, doi:10.3762/bjnano.7.32

• gluing unit for the assembly of often linear, hybrid structures of plasmonic gold (Au NP), magnetite (Fe3O4 NP), and cobalt ferrite nanoparticles (CoFe2O4 NP). Furthermore, the assembly of Au NPs into linear structures using Hcp1_cys3 is investigated by UV–vis spectroscopy, TEM and cryo-TEM. One key

• parameter for the formation of Au NP assembly is the specific ionic strength in the mixture. The resulting network-like structure of Au NPs is characterized by Raman spectroscopy, showing surface-enhanced Raman scattering (SERS) by a factor of 8·104 and a stable secondary structure of the Hcp1_cys3 unit. In

• order to prove the catalytic performance of the gold hybrid structures, they are used as a catalyst in the reduction reaction of 4-nitrophenol showing similar catalytic activity as the pure Au NPs. To further extend the functionality of the Hcp1_cys3 gluing unit, Fe3O4 and CoFe2O4 NPs are aligned in a

Evaluation of gas-sensing properties of ZnO nanostructures electrochemically doped with Au nanophases

• Elena Dilonardo,
• Michele Penza,
• Marco Alvisi,
• Cinzia Di Franco,
• Francesco Palmisano,
• Luisa Torsi and
• Nicola Cioffi

Beilstein J. Nanotechnol. 2016, 7, 22–31, doi:10.3762/bjnano.7.3

• stabilized gold nanoparticles (Au NPs) directly on the surface of nanostructured ZnO powders, previously synthesized through a sol–gel process. The effect of thermal annealing temperatures (300 and 550 °C) on chemical, morphological, and structural properties of pristine and Au-doped ZnO nancomposites (Au

• and time-consuming; furthermore, metal nanoparticles prepared in these way can undergo undesired clustering, thus lowering their catalytic activity [41]. In this contribution, sol–gel pre-synthesized and dried ZnO powder was directly functionalized with Au NPs of controlled size and loading by means

• nanostructures were lower than those of pristine and Au-doped ZnO nanorods, revealing that for NO2 gas-sensing the rod-like structure and the intimate contact between stabilized Au NPs and ZnO nanorods have a significant positive effect on the resistance of sensors and, consequently, their response. Experimental

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

•  3a. The electrically connected IDE with assembled Au NPs is immersed in a methanol (MeOH) bath, by taking care to leave the two electrode tracks outside of the liquid. Since the Au NPs are dispersable in water, the exposure to alcohol does not damage markedly the assembled film. Upon immersion of the

• representation of the concept of a dual electric/optical sensor made of a nanoparticle assembly connected by metal electrodes on a substrate. (a) Optical image of the IDE (Dropsens) electrically connected by conductor wires; (b) Optical image of a region containing Au NPs assembled as a strip between a pair of

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

• nanomaterials, since it offers rapid and uniform heating of the constituents [112]. Green reagents Saccharides Potara et al. found that chitosan (CTS) is not only capable of reducing and stabilizing, but it can aksi act as a scaffold for the formation of Au NPs. Their results indicated that the formation, size

• , shape and crystalline structure of Au NPs in a polymeric matrix are strongly influenced by the reaction temperature. At T = 100 °C and T = 20–50 °C, Au NPs had sizes of 18 and 27 nm, respectively, while at lower temperatures (4–10 °C), they observed anisotropic nanosheets of different shapes within the

• exhibited higher thermal stability of Ag–CTS in comparison to CTS. Their microbial experiments showed that the antibacterial performance of Ag–CTS is more than either Ag NPs or CTS [72]. Sun et al. prepared Au NPs using HAuCl4 as a precursor and CTS as the reducing agent and stabilizer in a 30 h reaction at

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

• order to remove any physisorbed APTES molecules. Prior to the deposition of AuNPs, all the glass substrates were dried in an oven at 90 °C for 1 h. As-prepared glass substrates were immersed in an aqueous solution of AuNPs for 8 h at room temperature to form monolayer of Au NPs on glass substrates. Then

• -functionalized glass substrate (b) the valance band maximum of samples (bare glass, APTES deposited glass and Au NPs deposited glass surface) obtained by linear extrapolations. UPS spectra of (a) AuNPs deposited on APTES-functionalized glass substrates with 24 h APTES deposition and 8 h AuNPs deposition and (b

• ) the valence band maximum of same samples obtained by linear extrapolations. AFM images of Au NPs deposited on silanized glass substrates, (a) without annealing (as deposited) (b) annealed in vacuum (c) annealed in air at 600 °C for 1 h. UV–visible absorption spectra of AuNPs deposited on APTES

Au nanoparticle-based sensor for apomorphine detection in plasma

• Chiara Zanchi,
• Andrea Lucotti,
• Matteo Tommasini,
• Sebastiano Trusso,
• Ugo de Grazia,
• Emilio Ciusani and
• Paolo M. Ossi

Beilstein J. Nanotechnol. 2015, 6, 2224–2232, doi:10.3762/bjnano.6.228

• unfiltered human blood plasma is presented and discussed. Keywords: apomorphine; Au NPs; nano-roughened films; pulsed laser deposition; self-assembled films; SERS; Introduction In recent years, the analytical applications of Raman spectroscopy and its enhanced variant employing plasmonic media, the surface

• such patients. Adjusting the APO concentration as it fluctuates with time is critical and is monitored via standardized clinical observations and tests of motor condition [21]. Standard chemical analysis (HPLC) on blood samples from the patient is an alternative to obtain the APO concentration. Au NPs

• substrates used as sensors for APO detection. The films consist of nearly spherical, mutually aggregated, Au NPs that give rise to islands with irregular shape, often interconnected with each other at specific sites. The channels with irregular shape and length separate adjacent islands. The insets of Figure

Fabrication of hybrid nanocomposite scaffolds by incorporating ligand-free hydroxyapatite nanoparticles into biodegradable polymer scaffolds and release studies

• Balazs Farkas,
• Marina Rodio,
• Ilaria Romano,
• Alberto Diaspro,
• Romuald Intartaglia and
• Szabolcs Beke

Beilstein J. Nanotechnol. 2015, 6, 2217–2223, doi:10.3762/bjnano.6.227

• conditions, and the versatility that allows for in situ manipulations [16]. Earlier, we had reported on the incorporation of Au NPs [19] and titanate nanotubes (TNTs) in and on the scaffolds [20] to develop poly(propylene fumarate)/diethyl fumarate (PPF:DEF) scaffolds for specific biomedical applications. We

• , and FTIR measurements similar to a previous work performed on Au NPs embedded in the same polymer matrix [19]. Shortly, 2D samples were made to measure the changes of penetration depth (and thus, the layer thickness), while five layer, non-porous circular scaffolds with 2 mm diameter were prepared for

• achieved for the most crucial first two weeks of the healing process. Experimental Poly(propylene fumarate) Poly(propylene fumarate) (PPF) has been chosen as the carrier for the HA nanoparticles following our previous success with gold nanoparticles (Au NPs) [19]. PPF itself is a versatile synthetic

Heterometal nanoparticles from Ru-based molecular clusters covalently anchored onto functionalized carbon nanotubes and nanofibers

• Deborah Vidick,
• Xiaoxing Ke,
• Michel Devillers,
• Claude Poleunis,
• Arnaud Delcorte,
• Pietro Moggi,
• Gustaaf Van Tendeloo and
• Sophie Hermans

Beilstein J. Nanotechnol. 2015, 6, 1287–1297, doi:10.3762/bjnano.6.133

• ammonium groups (–NMe3+) [38]. The bimetal Ru–Pt association is justified by possible applications in fuel cells as described above, while Au is also considered in this study since Au NPs supported on nanocarbons can be used as sensors for the detection of gases or various life-related molecules such as

Influence of size, shape and core–shell interface on surface plasmon resonance in Ag and Ag@MgO nanoparticle films deposited on Si/SiO_x

• Sergio D’Addato,
• Daniele Pinotti,
• Maria Chiara Spadaro,
• Guido Paolicelli,
• Vincenzo Grillo,
• Sergio Valeri,
• Luca Pasquali,
• Luca Bergamini and
• Stefano Corni

Beilstein J. Nanotechnol. 2015, 6, 404–413, doi:10.3762/bjnano.6.40

• , it was found that Au NPs [5] and Ag NPs [6] deposited on thin film- and wafer-based Si solar cells can enhance their photon absorption due to the occurrence of surface plasmon resonance (SPR), which serves to scatter the incident radiation in the UV–vis region and to increase the light trapping

• = /, was found to be AR = 2.0 ± 0.6. The high value of the estimated AR originates from deformation of a single NP, caused by interaction with the substrate and by the presence of small agglomerates during NP aggregation. With increasing values of tAg (i.e., when the number of deposited Au NPs is

Functionalized polystyrene nanoparticles as a platform for studying bio–nano interactions

• Cornelia Loos,
• Tatiana Syrovets,
• Anna Musyanovych,
• Volker Mailänder,
• Katharina Landfester,
• G. Ulrich Nienhaus and
• Thomas Simmet

Beilstein J. Nanotechnol. 2014, 5, 2403–2412, doi:10.3762/bjnano.5.250

• over positively charged ones may be unique. Thus, non-phagocytic cells, such as fibroblasts and endothelial cells, took up significantly more positively charged Au NPs than negatively charged Au NPs [47]. This emphasizes that the uptake of nanoparticles is highly cell type-dependent and the expression

Low-cost plasmonic solar cells prepared by chemical spray pyrolysis

• Erki Kärber,
• Atanas Katerski,
• Ilona Oja Acik,
• Valdek Mikli,
• Arvo Mere,
• Ilmo Sildos and
• Malle Krunks

Beilstein J. Nanotechnol. 2014, 5, 2398–2402, doi:10.3762/bjnano.5.249

• planar ZnO were prepared entirely by chemical spray pyrolysis. Au nanoparticles (Au-NPs) were formed via thermal decomposition of a gold(III) chloride trihydrate (HAuCl4·3H2O) precursor by spraying 2 mmol/L of the aqueous precursor solution onto a substrate held at 260 °C. Current–voltage scans and

• ], the thermal decomposition of a HAuCl4·3H2O precursor solution for Au-NP formation [8], and CIS/Au-NP and Au-NP/CIS composite layers prepared by spraying on glass [9]. In the composite layers, the Au-NPs assist photon absorption in the CIS absorber in the wavelength region of 500–800 nm [9]. Increased

• the solar cell, including the plasmonic NPs within the cell, has not yet been published. In the present study, Au-NP layers are deposited by CSP at various stages of the solar cell preparation. This work investigates which locations within the solar cell are optimal for the deposition of Au-NPs in

Liquid-phase exfoliated graphene: functionalization, characterization, and applications

• Mildred Quintana,
• Jesús Iván Tapia and
• Maurizio Prato

Beilstein J. Nanotechnol. 2014, 5, 2328–2338, doi:10.3762/bjnano.5.242

• nanoparticles (Au NPs) were introduced as contrast markers. Tiopronin and its fragments are well-known stabilizers for Au NPs. The analysis by transmission electron microscopy (TEM) showed Au NPs mostly resided on the nanofibers, thus supporting the proposed mechanism as shown in Figure 2. This methodology

• 1,3-dipolar cycloaddition. This product was compared with fresh exfoliated graphene by the derivatization of both products with PAMAN dendrons using an amide-bond condensation reaction [42]. Using Au NPs as markers, it was possible to visualize the reactive sites against each reaction. As expected

• , for the 1,3-dipolar cycloaddition reaction, the TEM micrographs showed Au NPs completely dispersed on graphene faces and edges. In contrast, for the amide-bond condensation reaction, Au NPs were mainly found on the graphene edges. These results were corroborated by HR-XPS analysis of the products. A

Localized surface plasmon resonances in nanostructures to enhance nonlinear vibrational spectroscopies: towards an astonishing molecular sensitivity

• Dan Lis and
• Francesca Cecchet

Beilstein J. Nanotechnol. 2014, 5, 2275–2292, doi:10.3762/bjnano.5.237

• of the Au NPs. According to the authors, the overall SFG signal from a dodecanethiol SAM was increased by one order of magnitude. If considering an ideal 100% surface coverage in Au NPs (which was not the case), the minimum amplification factor that can be deduced is 100. Also an important

• of a LSPR in the Au NPs. Since Tourillon et al. obtained a rather low SFG intensity when working with the same Au NPs layer functionalized with DDT, but probed in the external reflection geometry, one could believe that the contribution of the LSPR excitation was rather limited in the reported

• the suppression of the non-resonant background [90]. To provide quantitative signal intensity comparisons, the SE-CARS spectroscopy was applied to a 12 µm thick pyridine–Au NPs layer (red trace in Figure 11a), while conventional CARS was done on a 2 mm thick pyridine film (blue trace in Figure 11a