Investigating organic multilayers by spectroscopic ellipsometry: specific and non-specific interactions of polyhistidine with NTA self-assembled monolayers

• Ilaria Solano,
• Pietro Parisse,
• Ornella Cavalleri,
• Federico Gramazio,
• Loredana Casalis and
• Maurizio Canepa

Beilstein J. Nanotechnol. 2016, 7, 544–553, doi:10.3762/bjnano.7.48

• Experimental section. δΔ2,1 and δΨ2,1 difference spectra shown in Figure 4a,b are representative of the observed behavior. Despite the reduced refractive index mismatch between the film and the ambient and the use of cell windows tending to lower the signal-to-noise ratio, the emerging picture appears rather

Active multi-point microrheology of cytoskeletal networks

• Tobias Paust,
• Tobias Neckernuss,
• Lina Katinka Mertens,
• Ines Martin,
• Michael Beil,
• Paul Walther,
• Thomas Schimmel and
• Othmar Marti

Beilstein J. Nanotechnol. 2016, 7, 484–491, doi:10.3762/bjnano.7.42

• ability of the network to transmit mechanical forces. We also take a closer look at the influence of noise on lock-in measurements and state some simple rules for improving the signal-to-noise ratio. Keywords: cytoskeleton; intermediate filaments; lock-in technique; microrheology; optical tweezers

• closer look at the signal-to-noise ratio (SNR) is also necessary in order to to ensure applicability of the method over the whole range of experimentally accessible parameters. With this technique we characterized keratin networks with crosslinks of different strength. The concept of the lock-in

Length-extension resonator as a force sensor for high-resolution frequency-modulation atomic force microscopy in air

• Hannes Beyer,
• Tino Wagner and
• Andreas Stemmer

Beilstein J. Nanotechnol. 2016, 7, 432–438, doi:10.3762/bjnano.7.38

• comparable to the value measured by Giessibl et al. for signal-to-noise ratio calculations of the LER [9]. Compensation of environment-induced frequency shift The frequency shift signal Δf is a measure of the force gradient kts according to Δf = f0kts/2k, where f0 is the free resonance frequency. The high

Functional fusion of living systems with synthetic electrode interfaces

• Oskar Staufer,
• Sebastian Weber,
• C. Peter Bengtson,
• Hilmar Bading,
• Joachim P. Spatz and
• Amin Rustom

Beilstein J. Nanotechnol. 2016, 7, 296–301, doi:10.3762/bjnano.7.27

• -noise ratio is likely due to an increased electrical coupling coefficient based on the “close” contact between the sharp, monocrystalline electrode tips and the plasma membrane in combination with the PC isolation layer increasing the seal resistance. Comparable improvements of the signal-to-noise ratio

• were achieved with several nano- or microstructured electrode surfaces, such as chemically functionalized micrometer-sized mushroom-shaped gold protrusions [13][14], highlighting the general advantages of such surfaces over planar electrodes. The signal-to-noise ratio of intracellular NEI measurements

• potential changes frequently became detectable (Figure 3, green). These are well understood for Physarum p. and closely related to its oscillating cytoplasmic shuttle streaming that develops over a similar time frame [2]. When compared to PGE/PGE recordings, the significant enhancement of the signal-to

High-bandwidth multimode self-sensing in bimodal atomic force microscopy

• Michael G. Ruppert and
• S. O. Reza Moheimani

Beilstein J. Nanotechnol. 2016, 7, 284–295, doi:10.3762/bjnano.7.26

• strain sensitivity on the fifth eigenmode leading to a remarkable signal-to-noise ratio. Experimental results using bimodal AFM imaging on a two component polymer sample validate that the self-sensing scheme can therefore be used to provide both the feedback signal, for topography imaging on the

• values obtained during AFM imaging. To qualify the resolution of the overall AFM system, a noise image with the actively driven cantilever in contact with the sample surface should be acquired [35] which takes into account all contributing noise processes. Additionally, the signal-to-noise-ratio (SNR) is

Single-molecule mechanics of protein-labelled DNA handles

• Vivek S. Jadhav,
• Dorothea Brüggemann,
• Florian Wruck and
• Martin Hegner

Beilstein J. Nanotechnol. 2016, 7, 138–148, doi:10.3762/bjnano.7.16

• lengths, one can choose a certain trap separation during experiments that minimizes contributions due to crosstalk. DH lengths of 1000, 3034 and 4056 bp were chosen for the PDHs in this study. Short handles with greater stiffness could be produced quite easily and increase the signal-to-noise ratio (SNR

• increasing the distance between the two optically trapped beads. For nanomechanical experiments short molecular handles are preferred due to their increased mechanical stiffness, resulting in a favourable signal-to-noise ratio [14]. In order to achieve optimal positional and force resolution a balance had to

• the signal-to-noise ratio. The upper PDHs length limit is defined by the range of the steerable piezo-mirror (ca. 8 µm in the device used here). For tweezers systems utilizing a pipette and an optical trap (see Figure 1a–d) PDH molecules as short as 30 nm up to 30 µm can be investigated. Using these

Chemical bath deposition of textured and compact zinc oxide thin films on vinyl-terminated polystyrene brushes

• Nina J. Blumenstein,
• Caroline G. Hofmeister,
• Peter Lindemann,
• Cheng Huang,
• Johannes Baier,
• Andreas Leineweber,
• Stefan Walheim,
• Christof Wöll,
• Thomas Schimmel and
• Joachim Bill

Beilstein J. Nanotechnol. 2016, 7, 102–110, doi:10.3762/bjnano.7.12

• signal-to-noise ratio, PS brushes grafted to a Si-wafer coated with 10 nm SiO2, 100 nm Au and 5 nm Ti as adhesive layer between Au and Si were prepared [46]. For the sample measurement between 900 and 1300 scans have been cumulated, the spectra were recorded until no water bands could be observed in the

Probing the local environment of a single OPE3 molecule using inelastic tunneling electron spectroscopy

• Riccardo Frisenda,
• Mickael L. Perrin and
• Herre S. J. van der Zant

Beilstein J. Nanotechnol. 2015, 6, 2477–2484, doi:10.3762/bjnano.6.257

• extract a reliable IETS signal. In our approach, we record a large number of IVs, from which we calculate the first and the second derivative. We then divide point by point the second derivative by the first derivative to obtain the IETS signal. To increase the signal-to-noise ratio and reduce the effect

Blue and white light emission from zinc oxide nanoforests

• Nafisa Noor,
• Luca Lucera,
• Thomas Capuano,
• Venkata Manthina,
• Alexander G. Agrios,
• Helena Silva and
• Ali Gokirmak

Beilstein J. Nanotechnol. 2015, 6, 2463–2469, doi:10.3762/bjnano.6.255

• PIN diode to the sample was adjusted to achieve adequate signal-to-noise ratio without saturating the diode during the experiments. The voltage output of the built-in amplifier was significantly larger than any noise or perturbations coupled into the signal lines caused by the fast pulses. Hence, this

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

• experiences in the biological matrix as compared to the aqueous solution. To reach a comparable SERS intensity with respect to 100 µg/mL APO in water, an acquisition time of 10 s was applied, while 60 s was the acquisition time required for a reasonable signal-to-noise ratio of the SERS spectrum of 20 µg/mL

• by the selection of two SERS peaks. Minimal sample preparation and the capability to operate in an aqueous environment make the detection of APO by means of this technique rapid, with good signal-to-noise ratio, and characterized by adequate spatial reproducibility. The method is promising for

• dynamic range of the sensor To be considered a useful SERS-based method for drug detection, the procedure, based on the use of gold substrates pulsed laser deposition, should be rapid and quantitative. An acquisition time of 5 s, which corresponds to a fast measurement with an adequate signal-to-noise

Kelvin probe force microscopy for local characterisation of active nanoelectronic devices

• Tino Wagner,
• Hannes Beyer,
• Patrick Reissner,
• Philipp Mensch,
• Heike Riel,
• Bernd Gotsmann and
• Andreas Stemmer

Beilstein J. Nanotechnol. 2015, 6, 2193–2206, doi:10.3762/bjnano.6.225

• transitions and observations, respectively. As the noise at the output, , increases for a fixed , the bandwidth is reduced (Figure 7a). The ratio resembles a signal-to-noise ratio (SNR), which increases for large K and small filter bandwidths BW. The closed-loop bandwidth is a function of this SNR. Therefore

Electrochemical coating of dental implants with anodic porous titania for enhanced osteointegration

• Amirreza Shayganpour,
• Alberto Rebaudi,
• Pierpaolo Cortella,
• Alberto Diaspro and
• Marco Salerno

Beilstein J. Nanotechnol. 2015, 6, 2183–2192, doi:10.3762/bjnano.6.224

• measurements, given the limited thickness of APT, we had to use collecting conditions of low magnification (objective of 10×), high laser power (≈100 mW) and long accumulation time (1 min) to obtain spectra with reasonable signal to noise ratio. A representative Raman spectrum is presented in Figure 5

Imaging of carbon nanomembranes with helium ion microscopy

• André Beyer,
• Henning Vieker,
• Robin Klett,
• Hanno Meyer zu Theenhausen,
• Polina Angelova and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2015, 6, 1712–1720, doi:10.3762/bjnano.6.175

• particle microscopy techniques such as scanning electron microscopy (SEM) or helium ion microscopy (HIM). As illustrated in Supporting Information File 1, Figure S1, SEM shows a low signal-to-noise-ratio for freestanding CNMs, especially at higher magnifications, due to charging issues [4][16]. This tends

• to be destructive for freestanding membranes. For example, an attempt at imaging perforated CNMs with SEM failed due to charging-induced rupture during the imaging process [9]. On the other hand, HIM is very well-suited to image CNMs with high signal-to-noise-ratio at high magnification. In this

• , the high surface sensitivity of the HIM is well suited to obtain CNM images with high signal-to-noise-ratio. It is also important to note that the helium beam easily penetrates the CNM and also strikes objects below the freestanding membrane, for example, the sample holder. Figure 1 shows an example

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

• . Fortunately this has changed over the last decade. The introduction of spherical-aberration-corrected lenses [6] has paved the way out of this dilemma by improving the spatial resolution and increasing the signal to noise ratio at the same time. This has a dramatic impact when imaging at low accelerating

• generally accepted as reasonable. Additionally, the increase of the scattering cross section at low voltage improves the signal to noise ratio for light elements as carbon and results in an enhancement in contrast [38][49]. Following the discussion on lowering the voltage, the dose of incident electrons

• thus provide a HRTEM image with an acceptable signal to noise ratio with only limited damage to the sample. The introduction of a high-speed detector may also have an impact on increasing the time resolution. In a molecular dynamics simulations on the reconstruction of vacancies, the time scale is

Atomic force microscopy as analytical tool to study physico-mechanical properties of intestinal cells

• Christa Schimpel,
• Oliver Werzer,
• Eleonore Fröhlich,
• Gerd Leitinger,
• Markus Absenger-Novak,
• Birgit Teubl,
• Andreas Zimmer and
• Eva Roblegg

Beilstein J. Nanotechnol. 2015, 6, 1457–1466, doi:10.3762/bjnano.6.151

• . Although ESEM presents some additional beneficial features, considerable disadvantages including a high signal-to-noise ratio and/or limited resolution may arise [35]. In contrast, AFM allows high resolution (topographical) imaging of cells under (semi)hydrated, unfixed physiological conditions. Hence

Influence of the shape and surface oxidation in the magnetization reversal of thin iron nanowires grown by focused electron beam induced deposition

• Luis A. Rodríguez,
• Lorenz Deen,
• Rosa Córdoba,
• César Magén,
• Etienne Snoeck,
• Bert Koopmans and
• José M. De Teresa

Beilstein J. Nanotechnol. 2015, 6, 1319–1331, doi:10.3762/bjnano.6.136

• , we show in Figure 2a and Figure 2b the results for two nanowires from the second batch with tNom of 10 and 35 nm. The signal-to-noise ratio is ten, certainly enough to determine the coercive field, which is given by the measured MOKE field at the mid-point between the two saturation values at high

Scanning reflection ion microscopy in a helium ion microscope

• Yuri V. Petrov and
• Oleg F. Vyvenko

Beilstein J. Nanotechnol. 2015, 6, 1125–1137, doi:10.3762/bjnano.6.114

• the RIM measurements are obviously defined by the signal-to-noise ratio that increases with the image acquisition duration. There are two factors that limit measurement time in RIM: the ion beam induced deposition (IBID) of hydrocarbons and the sputtering of the surface material. The first problem

Entropy effects in the collective dynamic behavior of alkyl monolayers tethered to Si(111)

• Christian Godet

Beilstein J. Nanotechnol. 2015, 6, 583–594, doi:10.3762/bjnano.6.60

• of the OML. In contrast with alternative dynamic probes, such as nuclear magnetic resonance, which are limited by a poor signal-to-noise ratio and require functionalization of 3D nanoparticles or porous solids [3], admittance spectroscopy is sensitive to 0.3 picomoles of carboxylic acid dipoles [40

A scanning probe microscope for magnetoresistive cantilevers utilizing a nested scanner design for large-area scans

• Tobias Meier,
• Alexander Förste,
• Ali Tavassolizadeh,
• Karsten Rott,
• Dirk Meyners,
• Roland Gröger,
• Günter Reiss,
• Eckhard Quandt,
• Thomas Schimmel and
• Hendrik Hölscher

Beilstein J. Nanotechnol. 2015, 6, 451–461, doi:10.3762/bjnano.6.46

• a squared geometry used in this work shows the highest strain sensitivity of 2 × 10−7 Å, at a bias field angle α of 115° towards the magnetization of the reference layer. For this measurement, we can extract a signal-to-noise ratio of 900 at a bandwidth of 100 kHz which allows one to measure the

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

• and subcellular constituents in detail [110]. Spectral imaging and unmixing offers substantial improvement in signal-to-noise ratio and image contrast compared to the use of monochrome band-pass emission filters as employed in conventional fluorescence microscopes [111]. This approach also facilitates

Materials and characterization techniques for high-temperature polymer electrolyte membrane fuel cells

• Roswitha Zeis

Beilstein J. Nanotechnol. 2015, 6, 68–83, doi:10.3762/bjnano.6.8

• dissociate into H2PO4− ions, resulting in a rather small concentration of anions. In 1992, Nart and Iwasita [60] conducted similar experiments and reached very different conclusions. Their FTIR instrument had much improved signal-to-noise ratio and spectral resolution. Furthermore, they measured the FTIR

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

• angles for the pump, Stokes, and probe beams, while they further delayed the pump and the probe by 1ps to reduce the non-resonant contribution, and therefore enhance the signal-to-noise ratio. The authors attributed this poor enhancement factor to the increased scattering of light due to the NPs, to the

• ]. To circumvent that, various experimental means have been envisioned. In 2005, Koo et al. used a polarization-sensitive CARS setup to preferentially enhance the signal coming from the analytes with respect to the background. This procedure enabled them to achieve an extremely high signal to noise

• ratio and single molecule sensitivity [81]. The authors used a colloidal silver mixture in which the molecular concentration was chosen so that only a single molecule was found within the probed volume, in average. They reported the SE-CARS detection of single DNA nucleotide (dAMP and dGMP, 90 pM

Advances in NO₂ sensing with individual single-walled carbon nanotube transistors

• Kiran Chikkadi,
• Matthias Muoth,
• Cosmin Roman,
• Miroslav Haluska and
• Christofer Hierold

Beilstein J. Nanotechnol. 2014, 5, 2179–2191, doi:10.3762/bjnano.5.227

• ). Building on this concept, the authors have recently shown in [36] that combined with the use of ultraclean fabrication processes for gas sensors, suspended gas sensors showed a 9-fold improvement in the signal-to-noise ratio compared to on-substrate sensors as well as improved stability of the threshold

• voltage (Figure 9b). This increase in signal-to-noise ratio directly implies improved sensor resolution. Recovery For a sensor to be functional, it must be fully recoverable after each cycle of exposure to gas. For NO2 sensing using carbon nanotubes, this is a unique challenge. As discussed earlier, the

• noise performance, gas sensor products operating at extremely low powers can be envisioned. Compared to nanotube networks employing the same number of nanotubes, a better signal-to-noise ratio, lower power and smaller sizes could then be achieved. In this direction, suspended gas sensors appear to be

Data-adaptive image-denoising for detecting and quantifying nanoparticle entry in mucosal tissues through intravital 2-photon microscopy

• Torsten Bölke,
• Lisa Krapf,
• Regina Orzekowsky-Schroeder,
• Tobias Vossmeyer,
• Jelena Dimitrijevic,
• Horst Weller,
• Anna Schüth,
• Antje Klinger,
• Gereon Hüttmann and
• Andreas Gebert

Beilstein J. Nanotechnol. 2014, 5, 2016–2025, doi:10.3762/bjnano.5.210

• microscopy (2PM); denoising; in vivo imaging; nanoparticles; signal to noise ratio (SNR); quantum dots; Introduction Imaging methods applied to detect fluorescent nanoparticles in mucosal tissues should provide high optical resolution and allow large volumes to be scanned. An important and versatile tool

• under such conditions typically contain large amounts of noise, i.e., statistical variations of the pixel intensities that do not correspond to tissue structures. The signal to noise ratio (SNR) cannot readily be increased by slower scanning or binning, because this would critically affect the temporal

Dynamic calibration of higher eigenmode parameters of a cantilever in atomic force microscopy by using tip–surface interactions

• Stanislav S. Borysov,
• Daniel Forchheimer and
• David B. Haviland

Beilstein J. Nanotechnol. 2014, 5, 1899–1904, doi:10.3762/bjnano.5.200

• high-Q cantilevers, the measured response near each resonance may be separately detected with the high signal-to-noise ratio (SNR). Neglecting possible surface memory effects, F depends on the tip position z and its velocity only. With this assumption, the force model to be reconstructed has some