Bulk chemical composition contrast from attractive forces in AFM force spectroscopy

• Dorothee Silbernagl,
• Media Ghasem Zadeh Khorasani,
• Natalia Cano Murillo,
• Anna Maria Elert and
• Heinz Sturm

Beilstein J. Nanotechnol. 2021, 12, 58–71, doi:10.3762/bjnano.12.5

• measurements are easier to implement, since no additional sample preparation is necessary [20]. There is a number of AFM-based methods, such as tip-enhanced Raman spectroscopy (TERS) [21], AFM-based infrared spectroscopy (AFM-IR) [16][22], noncontact AFM (ncAFM ) [23][24], chemical AFM (cAFM) [25][26], and

• Kelvin probe force microscopy (KPM) [27] which were developed to identify local chemical or structural specificities in the samples. All the methods mentioned above are, to different degrees, advanced techniques which require additional equipment and expertise. TERS and AFM-IR are hybrid setups which

• include additional Raman and IR instrumentation, respectively. The effort to perform TERS or AFM-IR experiments is only justified if a detailed analysis of the chemical structure is needed. In this study, however, we aim to identify the material contrast which is provided by more accessible in situ

Nanomechanics of few-layer materials: do individual layers slide upon folding?

• Ronaldo J. C. Batista,
• Rafael F. Dias,
• Ana P. M. Barboza,
• Alan B. de Oliveira,
• Taise M. Manhabosco,
• Thiago R. Gomes-Silva,
• Matheus J. S. Matos,
• Andreij C. Gadelha,
• Cassiano Rabelo,
• Luiz G. L. Cançado,
• Ado Jorio,
• Hélio Chacham and
• Bernardo R. A. Neves

Beilstein J. Nanotechnol. 2020, 11, 1801–1808, doi:10.3762/bjnano.11.162

• any 2D material and not restricted to talc. This hypothesis was investigated employing a near-field tip-enhanced Raman spectroscopy (TERS) setup [36][37] that can probe strain variations across the edge of a folded graphene flake of 5 nm thickness (see Supporting Information File 1, section “Near

• -field tip-enhanced Raman spectroscopy”). Our TERS measurements (see Supporting Information File 1) do not show significant changes in the G band of the Raman spectra in the folded region. This either indicates a negligible strain in the fold region, or a combination of small compressive and tesile

• the bending stiffness on the flake thickness. For talc flakes with a thickness equal or larger than 5.3 nm, we obtained a scaling relation (κ ∝ h3) consistent with the Euler–Bernoulli beam theory, indicating that layers in sufficiently thick flakes do not slip to relieve strain. In contrast, TERS

Optically and electrically driven nanoantennas

• Monika Fleischer,
• Dai Zhang and
• Alfred J. Meixner

Beilstein J. Nanotechnol. 2020, 11, 1542–1545, doi:10.3762/bjnano.11.136

• spectroscopy (SERS); tip-enhanced Raman spectroscopy (TERS); tunnel junction; Editorial Optical antennas + serve to confine the energy of photons transported by a light wave to a tiny volume much smaller than the wavelength; or reversely, to convert the energy of an evanescent field that oscillates at optical

• or TERS) [6][7][8][9][10][11][12][13][14][15], as well as for (bio-)sensing applications [16][17][18]. The integration of nanoantennas can lead to enhanced functionality for optoelectronic devices, nano-light sources, light amplification, or hybrid systems in combination with nanoemitters or two

• . Prominent examples are SERS and TERS, where the intrinsically small Raman scattering cross-section is enhanced by several orders of magnitude, making single-molecule spectroscopy feasible. These spectroscopic techniques have shown tremendous progress in the last two decades [29][30][31][32]. Under high

Revealing the local crystallinity of single silicon core–shell nanowires using tip-enhanced Raman spectroscopy

• Marius van den Berg,
• Ardeshir Moeinian,
• Arne Kobald,
• Yu-Ting Chen,
• Anke Horneber,
• Steffen Strehle,
• Alfred J. Meixner and
• Dai Zhang

Beilstein J. Nanotechnol. 2020, 11, 1147–1156, doi:10.3762/bjnano.11.99

• (TERS) has distinguished itself as a powerful characterization technique, which allows to obtain both the morphology and the so-called chemical “finger print” information simultaneously with a resolution of a few nanometers. The key element of this technique is a sharp tip resembling a nanometer-scale

• ], TERS has made real chemical nanospectroscopy possible [26][27][28]. In this work, the structural properties of VLS-grown core–shell SiNWs are investigated using both confocal Raman spectroscopy and TERS. Notably, the silicon core is single crystalline while the shell should be amorphous to

• nanocrystalline, depending on the synthesis parameters. Hence, these nanowires resemble ideal objects to study local crystallinity variations at the sub-10 nanometer scale using TERS. Furthermore, polarization angle-resolved spectroscopy is for the first time combined with TERS, in order to reveal the different

Low cost tips for tip-enhanced Raman spectroscopy fabricated by two-step electrochemical etching of 125 µm diameter gold wires

• Antonino Foti,
• Francesco Barreca,
• Enza Fazio,
• Cristiano D’Andrea,
• Paolo Matteini,
• Onofrio Maria Maragò and
• Pietro Giuseppe Gucciardi

Beilstein J. Nanotechnol. 2018, 9, 2718–2729, doi:10.3762/bjnano.9.254

• spectroscopy (TERS) has become a well-applied technique for nanospectroscopy, allowing for single molecule sensitivity with sub-nanometer spatial resolution. The demand for efficient, reproducible and cost-effective probes for TERS is increasing. Here we report on a new electrochemical etching protocol to

• fabricate TERS tips starting from 125 µm diameter gold wires in a reproducible way. The process is reliable (50% of the tips have radius of curvature <35 nm, 66% <80 nm), fast (less than 2 min) and 2.5 times cheaper than the etching of standard 250 µm diameter wires. The TERS performance of the tips is

• tested on dyes, pigments and biomolecules and enhancement factors higher than 105 are observed. TERS mapping with a spatial resolution of 5 nm is demonstrated. Keywords: amyloid; enhanced spectroscopy; gold tips; plasmonics; TERS; Introduction Tip-enhanced Raman spectroscopy (TERS) combines the

Dumbbell gold nanoparticle dimer antennas with advanced optical properties

• Janning F. Herrmann and
• Christiane Höppener

Beilstein J. Nanotechnol. 2018, 9, 2188–2197, doi:10.3762/bjnano.9.205

• ). Usually, this end point of the antenna is not considered in common SERS applications due to the one to two orders of magnitude lower electromagnetic field strength. As a consequence, the signal majorly stems from the interparticle locations. However, for applications of such dimers in TENOM or TERS, the

• nanoparticles on a mirror substrate using defined spacer layers [47][48], in general, this approach is non-transferrable to tip-supported antennas used, e.g., in TENOM and TERS. Another frequently considered approach utilizes DNA as scaffold for the alignment of the nanoparticles [41][49][50]. In particular

Optical near-field mapping of plasmonic nanostructures prepared by nanosphere lithography

• Gitanjali Kolhatkar,
• Alexandre Merlen,
• Jiawei Zhang,
• Chahinez Dab,
• Gregory Q. Wallace,
• François Lagugné-Labarthet and
• Andreas Ruediger

Beilstein J. Nanotechnol. 2018, 9, 1536–1543, doi:10.3762/bjnano.9.144

• analysis with the high spatial resolution of scanning probe microscopy [3][4][5]. This method has been applied to various fields of research such as plasmonic analysis [6][7], Raman spectroscopy (tip-enhanced Raman spectroscopy, TERS) [8][9], or infrared analysis [10]. In this microscopy technique, a laser

• configuration provides a confined and strongly enhanced electromagnetic field at the tip apex. It has been shown in TERS measurements that depolarization mechanisms can be induced by the tip [27] while the exact physical origin remains unclear. We suggest that this feature accounts for the lack of polarization

• , thickness ≈33 nm) with a P6mm symmetry was obtained [19]. The optical absorption of the sample was measured: the nanotriangles array exhibit a broad resonance between 500 and 800 nm. Experimental setup The near-field studies were performed using an AIST-NT OmegaScope 1000 TERS system equipped with a

Growth model and structure evolution of Ag layers deposited on Ge films

• Arkadiusz Ciesielski,
• Lukasz Skowronski,
• Ewa Górecka,
• Jakub Kierdaszuk and
• Tomasz Szoplik

Beilstein J. Nanotechnol. 2018, 9, 66–76, doi:10.3762/bjnano.9.9

• stated earlier, the segregation-induced band in the permittivity spectrum is a plasmonic one [4], so the signal from Ge clusters in the voids between silver grains is most likely enhanced by localized plasmons excited on the silver grains, in a similar way as SERS or TERS, hence only the slight drop in

Near-field surface plasmon field enhancement induced by rippled surfaces

• Mario D’Acunto,
• Francesco Fuso,
• Ruggero Micheletto,
• Makoto Naruse,
• Francesco Tantussi and
• Maria Allegrini

Beilstein J. Nanotechnol. 2017, 8, 956–967, doi:10.3762/bjnano.8.97

• spectroscopy (TERS) [5], plasmonic photovoltaics [6][7][8], plasmonic nanosensors [9][10], and near-field optical theory [2][11][12]. It is commonly accepted that enormous field enhancements at the resonance of the optical response applied to randomly patterned metal nanostructures are highly dependent upon

• close proximity to a sample surface and illuminated by an external source [60][61]. Following the operating principles as in s-SNOM functionality, tip-enhanced Raman spectroscopy (TERS) involves keeping a metal nanostructure (tip) at a small distance above a sample, providing a highly localized field

• enhancement. Essentially, in this technique, a single-plasmon-resonant metallic nanostructure is provided in the form of a scanning probe tip of suitable material and geometry. Although TERS has been successfully applied in many applications, resulting in a powerful combination of SERS with Raman–AFM

Grazing-incidence optical magnetic recording with super-resolution

• Gunther Scheunert,
• Sidney. R. Cohen,
• René Kullock,
• Ryan McCarron,
• Katya Rechev,
• Ifat Kaplan-Ashiri,
• Ora Bitton,
• Paul Dawson,
• Bert Hecht and
• Dan Oron

Beilstein J. Nanotechnol. 2017, 8, 28–37, doi:10.3762/bjnano.8.4

• on a rough sample) and by following the AIST TERS tip alignment routine (performing an objective scan around the tip and recording the phase signal). This is in agreement with theoretical predictions for the optical setup in use (focal length of focusing objective = 20.3 mm, aperture diameter = 6 mm

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

• functionalized for the selective and sensitive detection of, for example, tumor cells [4]. Combining the SERS effect with scanning probe microscopy techniques (tip-enhanced Raman spectroscopy, TERS), molecular information can be obtained with high spatial resolution to show differences in the local chemical

Superluminescence from an optically pumped molecular tunneling junction by injection of plasmon induced hot electrons

• Kai Braun,
• Xiao Wang,
• Andreas M. Kern,
• Hilmar Adler,
• Heiko Peisert,
• Thomas Chassé,
• Dai Zhang and
• Alfred J. Meixner

Beilstein J. Nanotechnol. 2015, 6, 1100–1106, doi:10.3762/bjnano.6.111

• scattering (TERS) [11][12] or gap mode near-field optical microscopy [13]. This technique has attracted great interest as a means for local Raman [14][15] or luminescence spectroscopy [16] with nanometer spatial resolution. Since efficient Raman scattering from molecules in the gap requires gap widths as

• intensity increase of the laser-induced spectrum (i.e., the TERS-spectrum and its luminescence background) is about three orders of magnitude larger than the electroluminescence signal at Ub = 1800 mV under identical tunneling current, which is equivalent to a QE of almost 10−2 photons per tunneling

• a red-shifted maximum at 775 nm and a three times larger half-width. Both effects cannot be explained simply adding the TERS signal and its background at low bias voltage and the electroluminescence. Thus, an additional mechanism must be involved in the bias-voltage-dependent increase of the laser

Nano-FTIR chemical mapping of minerals in biological materials

• Sergiu Amarie,
• Paul Zaslansky,
• Yusuke Kajihara,
• Erika Griesshaber,
• Wolfgang W. Schmahl and
• Fritz Keilmann

Beilstein J. Nanotechnol. 2012, 3, 312–323, doi:10.3762/bjnano.3.35

• the acquisition time by 160,000× for a constant S/N ratio. Note that this positive perspective is in sharp contrast to tip-enhanced Raman scattering (TERS) for which up to 10 mW is readily available, but intrinsically weak cross sections leave little room for future signal improvement [57]. A

Distinction of nucleobases – a tip-enhanced Raman approach

• Regina Treffer,
• Xiumei Lin,
• Elena Bailo,
• Tanja Deckert-Gaudig and
• Volker Deckert

Beilstein J. Nanotechnol. 2011, 2, 628–637, doi:10.3762/bjnano.2.66

• of labeling or amplification steps. Here we investigate the intrinsic properties of tip-enhanced Raman scattering (TERS) towards the development of a novel, label-free, direct sequencing method. It is known that TERS allows the acquisition of spectral information with high lateral resolution and

• single-molecule sensitivity. In the presented experiments, single stranded adenine and uracil homopolymers were immobilized on different kinds of substrates (mica and gold nanoplates) and TERS experiments were conducted, which demonstrated the reproducibility of the technique. To elucidate the signal

• contributions from the specific nucleobases, TERS spectra were collected on single stranded calf thymus DNA with arbitrary sequence. The results show that, while the Raman signals with respect to the four nucleobases differ remarkably, specific markers can be determined for each respective base. The combination

Tip-enhanced Raman spectroscopic imaging of patterned thiol monolayers

• Johannes Stadler,
• Thomas Schmid,
• Lothar Opilik,
• Phillip Kuhn,
• Petra S. Dittrich and
• Renato Zenobi

Beilstein J. Nanotechnol. 2011, 2, 509–515, doi:10.3762/bjnano.2.55

• Raman spectroscopy (TERS) was used to measure the distribution of two isomeric thiols (2-mercaptopyridine (2-PySH) and 4-mercaptopyridine (4-PySH)) in a self-assembled monolayer (SAM) on a gold surface. From a patterned sample created by microcontact printing, an image with full spectral information in

• semi-quantitative information was deduced from the band intensities. Even though nanometer size resolution information was not required, the large signal enhancement of TERS was employed here to detect a monolayer coverage of weakly scattering analytes that were not detectable with normal Raman

• spectroscopy, emphasizing the usefulness of TERS. Keywords: mercaptopyridine; microcontact printing; monolayer; spectroscopic imaging; tip-enhanced Raman spectroscopy; Introduction The chemical characterization of surface adsorbates is of great interest in several areas of research. The composition of

Towards multiple readout application of plasmonic arrays

• Dana Cialla,
• Karina Weber,
• René Böhme,
• Uwe Hübner,
• Henrik Schneidewind,
• Matthias Zeisberger,
• Roland Mattheis,
• Robert Möller and
• Jürgen Popp

Beilstein J. Nanotechnol. 2011, 2, 501–508, doi:10.3762/bjnano.2.54

• with an optical readout were performed by several research groups: Roth et al. applied distance dependent tip-enhanced Raman spectroscopic (TERS) measurements, where SERS is combined with the SPM technique AFM (atomic force microscopy). These distance dependent TERS studies revealed that the highest