Refractive index sensing and surface-enhanced Raman spectroscopy using silver–gold layered bimetallic plasmonic crystals

• Somi Kang,
• Sean E. Lehman,
• Matthew V. Schulmerich,
• An-Phong Le,
• Tae-woo Lee,
• Stephen K. Gray,
• Rohit Bhargava and
• Ralph G. Nuzzo

Beilstein J. Nanotechnol. 2017, 8, 2492–2503, doi:10.3762/bjnano.8.249

• homometallic devices, the results presented herein illustrate improvements in performance that stem from the distinctive plasmonic features and strong localized electric fields produced by the Ag and Au layers, which are optimized in terms of metal thickness and geometric features. Finite-difference time

Au nanostructure fabrication by pulsed laser deposition in open air: Influence of the deposition geometry

• Rumen G. Nikov,
• Anna Og. Dikovska,
• Nikolay N. Nedyalkov,
• Georgi V. Avdeev and
• Petar A. Atanasov

Beilstein J. Nanotechnol. 2017, 8, 2438–2445, doi:10.3762/bjnano.8.242

• pulses) in order to investigate the structure of the material ablated. The TEM and selected area electron diffraction (SAED) images were taken on a HR scanning transmission electron microscope (STEM) (JEOL JEM 2100) to reveal the morphology and crystallinity of the as-deposited samples. For STEM

Involvement of two uptake mechanisms of gold and iron oxide nanoparticles in a co-exposure scenario using mouse macrophages

• Dimitri Vanhecke,
• Dagmar A. Kuhn,
• Dorleta Jimenez de Aberasturi,
• Sandor Balog,
• Ana Milosevic,
• Dominic Urban,
• Diana Peckys,
• Niels de Jonge,
• Wolfgang J. Parak,
• Alke Petri-Fink and
• Barbara Rothen-Rutishauser

Beilstein J. Nanotechnol. 2017, 8, 2396–2409, doi:10.3762/bjnano.8.239

• a scanning transmission electron microscopy (STEM) detector (described in detail below). The water layer covering the cells was carefully thinned until it was sufficiently thin to allow for the detection of single NPs in a cell with the STEM detector located under the sample. In order to easier

• min, rinsing three times with PBS supplemented with 1% BSA, and storage in this buffer at 4 °C until electron microscopic investigation. Wet ESEM-STEM An electron beam with an energy of 30 kV, a spot size of 1 nm, a probe current of 600 pA, and working distances between 6.0 and 6.4 mm were used. The

• sample, an overview ESEM-STEM image was recorded showing the whole membrane window area with all cells. Consequently, overview images were recorded from individual cells or cell groups at a higher magnification. To discern NPs on the plasma membrane, the magnification was set to 25,000× or 50,000×, and

Magnetic properties of optimized cobalt nanospheres grown by focused electron beam induced deposition (FEBID) on cantilever tips

• Soraya Sangiao,
• César Magén,
• Darius Mofakhami,
• Grégoire de Loubens and
• José María De Teresa

Beilstein J. Nanotechnol. 2017, 8, 2106–2115, doi:10.3762/bjnano.8.210

• analyze the chemical composition of the cobalt nanospheres by electron energy loss spectroscopy (EELS) in scanning transmission electron microscopy (STEM) mode and their local magnetic properties by electron holography in a transmission electron microscope (TEM), the specimens were prepared for TEM

• grown at the apex of the cantilever, following the same procedure as described above. Figure 3b,c displays the SEM micrographs of the two cobalt nanospheres studied by STEM-EELS and electron holography, once grown at the apex of cantilevers already attached to the TEM grid. The morphological and

• compositional properties of the cobalt nanospheres grown by FEBID have been confirmed by local chemical mapping of selected nanospheres of diameters 110 nm (see Figure 4b) and 90 nm (see Supporting Information File 1) performed by STEM-EELS. These quantitative maps reveal, first of all, that the deposits are

Synthesis and functionalization of NaGdF₄:Yb,Er@NaGdF₄ core–shell nanoparticles for possible application as multimodal contrast agents

• Dovile Baziulyte-Paulaviciene,
• Vitalijus Karabanovas,
• Marius Stasys,
• Greta Jarockyte,
• Vilius Poderys,
• Simas Sakirzanovas and
• Ricardas Rotomskis

Beilstein J. Nanotechnol. 2017, 8, 1815–1824, doi:10.3762/bjnano.8.183

• behavior in biological systems and biocompatibility/nanotoxicity is still limited. The study of Cascales et al. showed that ultrasmall Yb:Er:NaGd(WO4)2 UCNPs could be successfully covered with Tween 80 and are internalized by human mesenchymal stem cells without triggering their metabolic activity, but

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

• conjugated with targeting and chemotherapy agents, such as cancer stem cell-related antibodies and the anticancer drug doxorubicin, for early detection and improved treatment. In order to verify our findings, high-resolution transmission electron microscopy (HRTEM), atomic force microscopy (AFM), FTIR

Charge transfer from and to manganese phthalocyanine: bulk materials and interfaces

• Florian Rückerl,
• Daniel Waas,
• Bernd Büchner,
• Martin Knupfer,
• Dietrich R. T. Zahn,
• Francisc Haidu,
• Torsten Hahn and
• Jens Kortus

Beilstein J. Nanotechnol. 2017, 8, 1601–1615, doi:10.3762/bjnano.8.160

• -transfer compounds with a comparison of the electronic excitation spectra of MnPc, oxidized MnPc+ and reduced MnPc− as measured for the MnPc/F4TCNQ and K1MnPc compounds. We argue that for both compounds the low-energy excitations predominantly stem from MnPc-derived orbitals. In the case of K1MnPc this is

• electron escape depth (a few angstroms only [39]) the Mn 2p3/2 core-level data increasingly stem from regions very close to the interface with increasing F6TCNNQ top layer thickness. The data in Figure 10 demonstrate a clear change in line shape and energy position of the the Mn 2p3/2 core-level feature

• electronic 3d states of the central Co atom. The lowest lying absorption feature, which is maximal for a light polarization perpendicular to the F16CoPc molecules, can be assigned to transitions from the Co 2p into unoccupied states. The higher lying features stem from a multiplet structure related to the

Micro- and nano-surface structures based on vapor-deposited polymers

• Hsien-Yeh Chen

Beilstein J. Nanotechnol. 2017, 8, 1366–1374, doi:10.3762/bjnano.8.138

• cell pluripotency against mouse embryonic stem cells [72]. A plasma-polymerized surface with gradient amino functionality was demonstrated to generate density gradients of individual gold (Au) and silver (Ag) nanoparticles on the surfaces [73]. Poly(p-xylylene) surfaces with continuously and counter

• proliferation (FGF-2) and osteogenic differentiation (BMP-2) for adipose-derived stem cells [76]. Selective deposition The aforementioned methods rely on physical means to obtain spatially controlled surface modifications and patterned structures. A simpler approach is the selective inhibition of the vapor

Nano-engineered skin mesenchymal stem cells: potential vehicles for tumour-targeted quantum-dot delivery

• Liga Saulite,
• Dominyka Dapkute,
• Karlis Pleiko,
• Ineta Popena,
• Simona Steponkiene,
• Ricardas Rotomskis and
• Una Riekstina

Beilstein J. Nanotechnol. 2017, 8, 1218–1230, doi:10.3762/bjnano.8.123

• nanoparticles in imaging and targeted therapy of tumours. Due to their tumour-homing ability, nano-engineered mesenchymal stem cells (MSCs) could be utilized as vectors to deliver diagnostic and therapeutic nanoparticles into a tumour. In the present study, uptake and functional effects of carboxyl-coated

• suggest that QD-labelled MSCs could be used for targeted drug delivery studies. Keywords: endocytosis; mesenchymal stem cells; quantum dots; stem cell differentiation; Introduction Despite remarkable advances in targeted therapies of various human malignancies, cancer is one of the leading causes of

• drug carriers [3]. Recent studies have shown that nano-engineered mesenchymal stem cells (MSCs) could be used as tumour-targeted therapeutic carriers, reflecting their tumour-homing capabilities [4][5][6]. MSCs are present in many tissues of the human body, including bone marrow, adipose tissues, skin

Atomic structure of Mg-based metallic glass investigated with neutron diffraction, reverse Monte Carlo modeling and electron microscopy

• Rafał Babilas,
• Dariusz Łukowiec and
• Laszlo Temleitner

Beilstein J. Nanotechnol. 2017, 8, 1174–1182, doi:10.3762/bjnano.8.119

• , dark contrasts to be observed (Figure 9a). The area of the dark contrast regions calculated from the HAADF image is 4 × 6 nm. In addition, the EDS spectrum (Figure 9b) obtained in the HAADF-STEM mode confirmed the qualitative composition of the tested sample as the nanocrystalline material. Hirotsu et

• observations conducted in high-resolution mode. Further analysis of the ordered areas formed in the specimen annealed at 473 K for 1 h was provided by using STEM mode. The STEM bright field image presents some areas with a crystalline structure that indicate the formation of a primarly crystallization phase

• electron diffraction (SAED) pattern and details of the selected areas 1, 2, 3 (c,d,e) of a Mg65Cu20Y10Ni5 metallic glass after annealing at 473 K for 1 h. TEM images in (a) bright field and (b) dark field mode of a Mg65Cu20Y10Ni5 metallic glass sample after annealing at 473 K for 1 h. (a) HAADF-STEM image

AgCl-doped CdSe quantum dots with near-IR photoluminescence

• Pavel A. Kotin,
• Sergey S. Bubenov,
• Natalia E. Mordvinova and
• Sergey G. Dorofeev

Beilstein J. Nanotechnol. 2017, 8, 1156–1166, doi:10.3762/bjnano.8.117

• microscopy (STEM). Figure 5–e display the position of Cd, Se, Ag and Cl atoms. The investigation was made on the day of the synthesis of NPs. The colour brightness of one selected pixel is determined by the intensity of L (Cd, Se and Ag) or K (Cl) line in EDX spectrum. The element distribution maps show that

• and 300 kV, respectively. The latter has 0.17 nm point resolution and is equipped with an EDAX EDX detector. High-angle annular dark field (HAADF) STEM studies and EDX mapping were performed using an JEM ARM200F cold FEG double aberration-corrected electron microscope operated at 80 kV and equipped

• analysis of Ag content during aging of NPs. (a,b) Results obtained by using Equation 1 for samples AgCl_1 and AgCl_4, respectively. (c,d) Evolution of XRF spectra of samples AgCl_24 and AgCl_40 over time. Element distribution maps of sample AgCl_32 on the day of the synthesis of NPs. (a) HAADF-STEM image

ZnO nanoparticles sensitized by CuInZn_xS_2+x quantum dots as highly efficient solar light driven photocatalysts

• Florian Donat,
• Serge Corbel,
• Halima Alem,
• Steve Pontvianne,
• Lavinia Balan,
• Ghouti Medjahdi and
• Raphaël Schneider

Beilstein J. Nanotechnol. 2017, 8, 1080–1093, doi:10.3762/bjnano.8.110

• production of 1O2 was evaluated by measuring the photoluminescence of SOSG–endoperoxide (SOSG-EP) (λex = 480 nm and λem = 525 nm) [42]. Instruments and characterization Transmission electron microscopy (TEM) investigations were performed with a JEOL ARM 200F – Cold FEG TEM/STEM (point resolution 0.19 nm in

• TEM mode and 0.078 nm in STEM mode) fitted with a GIF Quatum ER. High-resolution TEM (HR-TEM) imaging was performed with a JEOL ARM 200F – Cold FEG (point resolution 0.19 nm) fitted with a GIF Quatum ER. For each sample, one drop of a dispersed solution was deposited on holey carbon grids and imaged

Stable Au–C bonds to the substrate for fullerene-based nanostructures

• Taras Chutora,
• Jesús Redondo,
• Bruno de la Torre,
• Martin Švec,
• Pavel Jelínek and
• Héctor Vázquez

Beilstein J. Nanotechnol. 2017, 8, 1073–1079, doi:10.3762/bjnano.8.109

• assume that the varying apparent heights of these molecules inside the island stem from different adsorption geometries and possibly the local influence of neighboring molecules. Finally, we observe dark spots in the islands (black arrows in Figure 2b), which we can attribute to holes formed due to the

Structural properties and thermal stability of cobalt- and chromium-doped α-MnO₂ nanorods

• Romana Cerc Korošec,
• Polona Umek,
• Alexandre Gloter,
• Jana Padežnik Gomilšek and
• Peter Bukovec

Beilstein J. Nanotechnol. 2017, 8, 1032–1042, doi:10.3762/bjnano.8.104

• synthesized at 170 °C is significantly lower than in the undoped samples. Analysis of an individual cobalt-doped α-MnO2 nanorod with HAADF-STEM reveals that the distribution of cobalt through the cross-section of the nanorod is uniform. The course of thermal decomposition of the doped nanorods is similar to

• transmission electron microscopy (HAADF-STEM), both shown in Figure 7. The chemical profiles of manganese and oxygen show a correlation with the nanorod shape while the cobalt profile shows more fluctuations due to the rather lower cobalt content (1.3 atom %). Nevertheless, it is clear that cobalt is present

• the material under X-ray irradiation. The IFEFFIT program package [33] was used for the XANES (X-ray absorption near edge structure) and EXAFS (extended X-ray absorption fine structure) analysis. High-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) images were acquired

Energy-level alignment at interfaces between manganese phthalocyanine and C₆₀

• Daniel Waas,
• Florian Rückerl,
• Martin Knupfer and
• Bernd Büchner

Beilstein J. Nanotechnol. 2017, 8, 927–932, doi:10.3762/bjnano.8.94

• features or energy shifts would be expected. We now turn to the discussion of the N1s core level data as obtained from the two deposition series, which are depicted in Figure 1c and Figure 1d. These data stem from MnPc only and, thus, allow insight into the behavior of one side of the interface under

3D Nanoprinting via laser-assisted electron beam induced deposition: growth kinetics, enhanced purity, and electrical resistivity

• Brett B. Lewis,
• Robert Winkler,
• Xiahan Sang,
• Pushpa R. Pudasaini,
• Michael G. Stanford,
• Harald Plank,
• Raymond R. Unocic,
• Jason D. Fowlkes and
• Philip D. Rack

Beilstein J. Nanotechnol. 2017, 8, 801–812, doi:10.3762/bjnano.8.83

• roughly 45° relative to the FEI GIS. Figure 1 is a schematic illustrating the geometry of the gas and laser delivery systems relative to the substrate and electron beam impact point. STEM imaging and EELS analysis Scanning transmission electron microscope (STEM) imaging and electron energy loss

• (BF) STEM imaging was used to analyze the structure of the nanoscale deposits before and after laser annealing. EELS was performed in order to determine the structure of carbon through analysis of the carbon K-edge. Electrical device fabrication and measurements A two-contact electrical test structure

• ) has a higher growth rate and higher segment angle for comparable dwell times. STEM imaging and EELS STEM was used to investigate the morphology of the as-deposited and laser treated structures. In addition, the chemical nature of the carbon was characterized for different EBID configurations using

First examples of organosilica-based ionogels: synthesis and electrochemical behavior

• Andreas Taubert,
• Ruben Löbbicke,
• Barbara Kirchner and
• Fabrice Leroux

Beilstein J. Nanotechnol. 2017, 8, 736–751, doi:10.3762/bjnano.8.77

• with zoom-ins to the central areas of the plot vs temperature. Variation of log(σ·T) versus 1000/T for all IGs. The change in the energy of activation likely does not stem from a weight loss process such as a weak dehydration because there is no apparent thermal event below 100 °C. However, data

Ion beam profiling from the interaction with a freestanding 2D layer

• Ivan Shorubalko,
• Kyoungjun Choi,
• Michael Stiefel and
• Hyung Gyu Park

Beilstein J. Nanotechnol. 2017, 8, 682–687, doi:10.3762/bjnano.8.73

• beam source. For imaging the milled pores we use scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM) and helium ion microscopy (HIM). All methods give similar results regarding the measured focused ion beam profiles. Finally, we discuss technical limitations and

• , freestanding graphene membranes were exposed to a Ga+ focused ion beam. The smallest beam aperture gives a beam current value of 1.5 pA. A suspended graphene layer is then exposed in a single-pixel exposure mode. Figure 1a shows a STEM bright field (BF) image of seven pores milled into graphene with different

• : squares for 1.5 pA and circles for 18 pA beam current. STEM dark field (DF) images of a pore array created with 18 pA beam current are shown in the inset of Figure 1d. The pore diameter vs ion exposure dose curves have very distinct shape Figure 1d. Pore diameters steeply increase for the low exposure

Self-assembly of silicon nanowires studied by advanced transmission electron microscopy

• Marta Agati,
• Guillaume Amiard,
• Vincent Le Borgne,
• Paola Castrucci,
• Richard Dolbec,
• Maurizio De Crescenzi,
• My Alì El Khakani and
• Simona Boninelli

Beilstein J. Nanotechnol. 2017, 8, 440–445, doi:10.3762/bjnano.8.47

• Dipartimento di Fisica, Università di Roma “Tor Vergata”, Via della Ricerca Scientifica 1, Roma 00133, Italy, Tekna Plasma Systems Inc., 2935 Industrial Blvd., Sherbrooke QC-J1L 2T9, Canada 10.3762/bjnano.8.47 Abstract Scanning transmission electron microscopy (STEM) was successfully applied to the analysis

• possess a nanoparticle at their tip. STEM energy dispersive X-ray (EDX) spectroscopy combined with electron tomography performed on these nanostructures revealed that they contain iron, clearly demonstrating that the short ICP-synthesized SiNWs grew via an iron-catalyzed vapor–liquid–solid (VLS) mechanism

• within the plasma reactor. Both the STEM tomography and STEM-EDX analysis contributed to gain further insight into the self-assembly process. In the long-term, this approach might be used to optimize the synthesis of VLS-grown SiNWs via ICP as a competitive technique to the well-established bottom-up

Role of oxygen in wetting of copper nanoparticles on silicon surfaces at elevated temperature

• Tapas Ghosh and
• Biswarup Satpati

Beilstein J. Nanotechnol. 2017, 8, 425–433, doi:10.3762/bjnano.8.45

• the high-angle annular dark-field scanning transmission electron microscopy (STEM-HAADF). After the TEM analysis, the same samples were transferred to a rapid thermal annealing unit (model: JETFIRST100 jipelec) and annealing was performed in air, oxygen and nitrogen atmospheres, one by one. The rapid

• field TEM image in Figure 1a and the STEM-HAADF image in Figure 1b show the deposited copper nanoparticles on a silicon substrate. The elemental composition is presented by the EDX mapping. Figure 1e and Figure 1f show the silicon (yellow) and copper (blue) elemental mapping, respectively, collected

• from a region marked by an orange rectangle in the STEM-HAADF image in Figure 1b. The thermal oxidation was performed in a rapid thermal annealing system at 500 °C for 1 min. We have analyzed the phase of the as-deposited material and the samples annealed under oxygen atmosphere by selected area

Biological and biomimetic materials and surfaces

• Stanislav Gorb and
• Thomas Speck

Beilstein J. Nanotechnol. 2017, 8, 403–407, doi:10.3762/bjnano.8.42

• shrubby monocotyledons plants with an emphasis on the structure–function relationships in Dracaena marginata stems [11]. Based on the results of microscopy and mechanical testing, a model of mechanical interactions between tissues and vascular bundles in the D. marginata stem was generated, and the

Uptake of the proteins HTRA1 and HTRA2 by cells mediated by calcium phosphate nanoparticles

• Olga Rotan,
• Katharina N. Severin,
• Simon Pöpsel,
• Alexander Peetsch,
• Melisa Merdanovic,
• Michael Ehrmann and
• Matthias Epple

Beilstein J. Nanotechnol. 2017, 8, 381–393, doi:10.3762/bjnano.8.40

• humidified atmosphere and cultivated according to standard cell culture protocols. A primary cell culture of human mesenchymal stem cells (hMSCs) was cultivated using mesenchymal stem cell (MSC) growth medium, supplemented according to the standard cultivation protocol. Approximately 12 h prior to the

Optical and photocatalytic properties of TiO₂ nanoplumes

• Viviana Scuderi,
• Massimo Zimbone,
• Maria Miritello,
• Giuseppe Nicotra,
• Giuliana Impellizzeri and
• Vittorio Privitera

Beilstein J. Nanotechnol. 2017, 8, 190–195, doi:10.3762/bjnano.8.20

• statistical analysis showed that he roughness of the surface and the porosity of the structure increase with the etching time. In Figure 2a, a cross-sectional view STEM image of Ti (430-190) is reported. The sample shows the presence of a nanostructured material. The etching clearly expands from the surface

• analyses in plan view were performed by a field emission Zeiss Supra 25 microscope. TEM analyses were performed in cross-sectional view with a JEOL JEM ARM200CF in scanning mode (STEM) at 60 kV of beam acceleration voltage using the microscope installed at the Beyond-Nano laboratory in Catania (Italy). The

Influence of hydrofluoric acid treatment on electroless deposition of Au clusters

• Rachela G. Milazzo,
• Antonio M. Mio,
• Giuseppe D’Arrigo,
• Emanuele Smecca,
• Alessandra Alberti,
• Gabriele Fisichella,
• Filippo Giannazzo,
• Corrado Spinella and
• Emanuele Rimini

Beilstein J. Nanotechnol. 2017, 8, 183–189, doi:10.3762/bjnano.8.19

• plating solution. The morphology of gold was examined with plan view TEM and scanning transmission electron microscopy (STEM) in high-angle annular dark-field imaging (HAADF) Z-contrast (atomic number) imaging mode, while the crystalline structure was analyzed in detail with X-ray diffraction. Figure 4a

• and Figure 4b are the plan view TEM of the samples before and after the HF postdeposition treatment for 70 s. The more discernible effect is a pronounced change in the fractional covered area that varies by about 15%. By using a STEM detector with a large inner radius (a HAADF detector) electrons are

• collected which are not Bragg scattered. As such HAADF images show little or no diffraction effects, and their intensity is approximately proportional to Z2. The HF postdeposition treatment levels off the intensity distribution of the corresponding STEM micrograph, indicating a more uniform thickness for

A novel electrochemical nanobiosensor for the ultrasensitive and specific detection of femtomolar-level gastric cancer biomarker miRNA-106a

• Maryam Daneshpour,
• Kobra Omidfar and
• Hossein Ghanbarian

Beilstein J. Nanotechnol. 2016, 7, 2023–2036, doi:10.3762/bjnano.7.193

• concentrations in eight independent assays. Quantification of miR-106a by stem-loop RT-PCR After preparing a serial dilution of miR-106a, cDNA was synthesized using s stem-loop primer and M-MuLV reverse transcriptase, and then quantified on an Applied Biosystems 7900HT sequence detection system by using a SYBR