Magnetic-field-assisted synthesis of anisotropic iron oxide particles: Effect of pH

• Andrey V. Shibaev,
• Petr V. Shvets,
• Darya E. Kessel,
• Roman A. Kamyshinsky,
• Anton S. Orekhov,
• Sergey S. Abramchuk,
• Alexei R. Khokhlov and
• Olga E. Philippova

Beilstein J. Nanotechnol. 2020, 11, 1230–1241, doi:10.3762/bjnano.11.107

• reference sample (20–50 nm). It is well known that distinguishing between magnetite (Fe3O4) and maghemite (γ-Fe2O3) only using the diffraction technique is not straightforward. However, these samples can be easily distinguished by Raman scattering, since Fe3O4, γ-Fe2O3 and other iron oxides and hydroxides

• to excite the Raman scattering. The irradiation power density on the sample was continuously decreased (using neutral density filters and beam defocusing) until no further changes were observed in the obtained spectra. A power of ≈0.2 mW on the sample and a laser spot diameter of ≈30 μm were

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

• microscopy images. Additionally, the polarizations of Raman scattering and the photoluminescence signal from the tip–sample nanogap are explored by combining polarization angle-resolved emission spectroscopy with tip-enhanced optical spectroscopy. Our work demonstrates the significant potential of resolving

• polarizations of Raman scattering and the photoluminescence from the tip–sample nanogap. Results and Discussion Silicon nanowire core–shell morphology In accordance with the VLS synthesis method (see Experimental section), the utilized Pt catalyst, or finally PtxSiy, remains at the tip of the nanowire during

• ratio between the crystalline Si and amorphous Si Raman peaks at sample positions as close as eight nanometers can be revealed. Furthermore, the polarizations of Raman scattering and photoluminescence signals locally emitted from a single SiNW are explored by combining polarization angle-resolved

Highly sensitive detection of estradiol by a SERS sensor based on TiO₂ covered with gold nanoparticles

• Andrea Brognara,
• Ili F. Mohamad Ali Nasri,
• Beatrice R. Bricchi,
• Andrea Li Bassi,
• Caroline Gauchotte-Lindsay,
• Matteo Ghidelli and
• Nathalie Lidgi-Guigui

Beilstein J. Nanotechnol. 2020, 11, 1026–1035, doi:10.3762/bjnano.11.87

• -enhanced Raman scattering (SERS) sensors for the detection of 17β-estradiol. Gold deposition on top of a TiO2 surface leads to the formation of nanoparticles the plasmonic properties of which fulfil the requirements of a SERS sensor. The morphological and optical properties of the surface were investigated

• -estradiol, an emerging contaminant in environmental waters. We have found a limit of detection of 1 nM with a sensitivity allowing for a dynamic range of five orders of magnitude (up to 100 µM). Keywords: aptamer; Au nanoparticles; 17-β estradiol (E2); plasmonics; sensor; surface-enhanced Raman scattering

• (SERS); TiO2 nanostructures; Introduction Surface-enhanced Raman scattering (SERS) as a sensing tool requires the optimization of a surface and its functionalization. The surface should provide a good enhancement over a large range of wavelengths, to detect molecules with various fingerprints, while it

Band tail state related photoluminescence and photoresponse of ZnMgO solid solution nanostructured films

• Vadim Morari,
• Aida Pantazi,
• Nicolai Curmei,
• Vitalie Postolache,
• Emil V. Rusu,
• Marius Enachescu,
• Ion M. Tiginyanu and
• Veaceslav V. Ursaki

Beilstein J. Nanotechnol. 2020, 11, 899–910, doi:10.3762/bjnano.11.75

• , the results showed that films are deposited with wurtzite structure as the dominant phase even after phase segregation in the investigated Mg concentration interval. The issue of phase segregation was also investigated via selective resonant Raman scattering in a wider composition range of x = 0.00

• about 400 meV. One can see from Figure 4 and Figure 5 that narrow emission lines related to resonance Raman scattering (RRS) are present in the emission spectrum from the ZnMgO films in addition to the broad PL bands, which is indicative of the high optical properties of the films produced by sol–gel

• summarized PL band maximum in Zn1−xMgxO films. The conditions of resonance Raman scattering in ZnMgO films for various compositions and temperatures. Funding The following sources of funding are acknowledged: National Agency for Research and Development of the Republic of Moldova (Grant No

Light–matter interactions in two-dimensional layered WSe₂ for gauging evolution of phonon dynamics

• Avra S. Bandyopadhyay,
• Chandan Biswas and
• Anupama B. Kaul

Beilstein J. Nanotechnol. 2020, 11, 782–797, doi:10.3762/bjnano.11.63

• -dimensionality nanocrystallites, the wave function of the optical phonons no longer remains a continuous plane wave and thus the localization of the wave function leads to a relaxation in the conservation of the wave vector selection rules. The phonons with a nonzero wave vector also take part in the Raman

• scattering process along with the phonons with zero wave vector, which results in broadening of the phonon linewidths. Another important parameter in this analysis is the actual position of the allowable Raman modes, which are typically the higher energy optical phonons, and how these modes interact with

Soybean-derived blue photoluminescent carbon dots

• Shanshan Wang,
• Wei Sun,
• Dong-sheng Yang and
• Fuqian Yang

Beilstein J. Nanotechnol. 2020, 11, 606–619, doi:10.3762/bjnano.11.48

• due to the Raman scattering of the water [35]. The annealed-CDs show no PL under irradiation with UV–vis light. Note that the sharp peaks in Figure 3b represent the Raman scattering of water (solvent) only, indicating that there is no photoluminescence emission from the annealed-CDs under excitation

• at various wavelengths. The Raman scattering of the annealed CDs has a relatively low yield. The Raman peaks can be only observed when the gain or slit bandwidth of the instrument is increased to compensate for the low fluorescence signal. In contrast to the annealed-CDs, the LA-CDs-10%, which are

• peaks in the photoluminescence spectrum are from the water Raman scattering. The broad peaks of the emissions at 418, 422 and 436 nm have much weaker intensities than the water Raman scattering, suggesting that the PL intensity from laser-ablated Teflon is negligible. Thus, both the HTC-CDs and the LA

Evolution of Ag nanostructures created from thin films: UV–vis absorption and its theoretical predictions

• Robert Kozioł,
• Marcin Łapiński,
• Paweł Syty,
• Damian Koszelow,
• Wojciech Sadowski,
• Józef E. Sienkiewicz and
• Barbara Kościelska

Beilstein J. Nanotechnol. 2020, 11, 494–507, doi:10.3762/bjnano.11.40

• field is extremely important is surface-enhanced Raman scattering (SERS), where Raman spectra can be enhanced by several orders of magnitude. However, there are many other areas where it is possible to increase the efficiency of equipment by increasing the electromagnetic field around metal

Label-free highly sensitive probe detection with novel hierarchical SERS substrates fabricated by nanoindentation and chemical reaction methods

• Jingran Zhang,
• Tianqi Jia,
• Yongda Yan,
• Li Wang,
• Peng Miao,
• Yimin Han,
• Xinming Zhang,
• Guangfeng Shi,
• Yanquan Geng,
• Zhankun Weng,
• Daniel Laipple and
• Zuobin Wang

Beilstein J. Nanotechnol. 2019, 10, 2483–2496, doi:10.3762/bjnano.10.239

• surface-enhanced Raman scattering (SERS) substrates. Recently, in order to obtain a higher enhancement factor at a lower detection limit, hierarchical structures, including nanostructures and nanoparticles, appear to be viable SERS substrate candidates. Here we describe a novel method integrating the

• sensitive, hierarchical SERS substrate. Keywords: Ag nanoparticles; hierarchical substrates; malachite green molecules; nanoindentation; nanostructures; R6G; SERS; Introduction Surface-enhanced Raman scattering (SERS) has triggered significant research interest due to its suitability as an analytical tool

• for the ultrasensitive detection of molecules [1][2][3][4]. Compared with traditional Raman scattering technology, SERS is a surface phenomenon associated with the amplification of Raman intensity by several orders of magnitude for analyte molecules. The high resolution results from the combination of

The role of Ag⁺, Ca²⁺, Pb²⁺ and Al³⁺ adions in the SERS turn-on effect of anionic analytes

• Stefania D. Iancu,
• Andrei Stefancu,
• Vlad Moisoiu,
• Loredana F. Leopold and
• Nicolae Leopold

Beilstein J. Nanotechnol. 2019, 10, 2338–2345, doi:10.3762/bjnano.10.224

• -Napoca, Romania 10.3762/bjnano.10.224 Abstract In our recent studies we highlighted the role of adsorbed ions (adions) in turning on the surface-enhanced Raman scattering (SERS) effect in a specific mode for anionic and cationic analytes. In this work, we emphasize the role of Ag+, Ca2+, Pb2+ and Al3

• of higher affinities to the silver surface as indicated by the SERS spectra of corresponding mixed solutions. Keywords: adion-specific adsorption model; cation bridging; Raman; surface enhanced Raman scattering (SERS); Introduction Surface-enhanced Raman scattering (SERS) is an ultrasensitive

• +–halide–organic molecule is formed that allows a charge transfer between the metal surface and the molecule leading to a resonant Raman scattering effect [6][7][8]. Evidence for surface complexes were provided by several SERS experiments on silver electrodes [3][8], but also on colloidal silver

Review of advanced sensor devices employing nanoarchitectonics concepts

• Katsuhiko Ariga,
• Tatsuyuki Makita,
• Masato Ito,
• Taizo Mori,
• Shun Watanabe and
• Jun Takeya

Beilstein J. Nanotechnol. 2019, 10, 2014–2030, doi:10.3762/bjnano.10.198

• devices. Of course, all important sensor activities cannot be described in this review. For example, sensors based on various advanced physical mechanisms such as plasmonic [194], dielectric sensing [195], surface-enhanced Raman scattering [196], Fabry–Pérot-based intraocular pressure [197], and/or novel

Materials nanoarchitectonics at two-dimensional liquid interfaces

• Katsuhiko Ariga,
• Michio Matsumoto,
• Taizo Mori and
• Lok Kumar Shrestha

Beilstein J. Nanotechnol. 2019, 10, 1559–1587, doi:10.3762/bjnano.10.153

• transfer within the assembled structures. Acharya, Shrestha, and co-workers decorated one-dimensional C60 nanorods with zero-dimensional Ag nanoparticles that were used as substrates for surface-enhanced Raman scattering (SERS) to detect model targets such as rhodamine 6G with high sensitivity [246]. This

A silver-nanoparticle/cellulose-nanofiber composite as a highly effective substrate for surface-enhanced Raman spectroscopy

• Yongxin Lu,
• Yan Luo,
• Zehao Lin and
• Jianguo Huang

Beilstein J. Nanotechnol. 2019, 10, 1270–1279, doi:10.3762/bjnano.10.126

• Raman scattering (SERS) substrate was developed by facile deposition of silver nanoparticles onto cellulose fibers of ordinary laboratory filter paper. This was achieved by means of the silver mirror reaction in a manner to control both the size of the silver nanoparticles and the silver density of the

• characteristic Raman scattering bands of R6G at relatively high concentrations (Figure 4; Supporting Information, Figure S6). As marked in Figure 4b, the bands located at 611, 771, and 1125 cm−1 are assigned to the C–C–C ring in-plane, out-of-plane bending, and C–H in-plane bending vibrations, respectively; and

Correlation of surface-enhanced Raman scattering (SERS) with the surface density of gold nanoparticles: evaluation of the critical number of SERS tags for a detectable signal

• Vincenzo Amendola

Beilstein J. Nanotechnol. 2019, 10, 1016–1023, doi:10.3762/bjnano.10.102

• Vincenzo Amendola Department of Chemical Sciences, University of Padova, Padova, Italy 10.3762/bjnano.10.102 Abstract The use of plasmonic nanotags based on the surface-enhanced Raman scattering (SERS) effect is highly promising for several applications in analytical chemistry, biotechnological

• suitability of plasmonic SERS labels for ultrasensitive analytical and biomedical applications is evident. Keywords: discrete dipole approximation (DDA); gold nanoparticles (AuNPs); nanotags; surface-enhanced Raman scattering (SERS); surface plasmon resonance (SPR); Introduction In surface-enhanced Raman

• scattering (SERS), the Raman scattering cross-section of molecules adsorbed on the surface of plasmonic nanostructures is enormously increased compared to the same isolated molecules [1][2][3][4][5]. In particular, the SERS enhancement factor can reach values as high as 1012, which can be attributed to two

Fabrication of silver nanoisland films by pulsed laser deposition for surface-enhanced Raman spectroscopy

• Bogusław Budner,
• Mariusz Kuźma,
• Barbara Nasiłowska,
• Bartosz Bartosewicz,
• Malwina Liszewska and
• Bartłomiej J. Jankiewicz

Beilstein J. Nanotechnol. 2019, 10, 882–893, doi:10.3762/bjnano.10.89

• and characterization of silver nanoisland films (SNIFs) using pulsed laser deposition (PLD) and the evaluation of these films as potential surface-enhanced Raman scattering (SERS) substrates are reported. The SNIFs with thicknesses in a range of 4.7 ± 0.2 nm to 143.2 ± 0.2 nm were deposited under

• occurs. This effect is visible during excitation with 633 nm, but the enhancement becomes even more pronounced when the excitation wavelength shifts to 532 nm. As it is known, the total enhancement of the Raman scattering signal in the SERS phenomenon depends on the EM (electromagnetic) and CT (charge

• transfer) effect. In the CT mechanism the charge transfer between the molecules of the analyte and metallic nanostructures is excited, which leads to a resonant increase in the total EF. When the laser energy matches the energy gap between the HOMO and LUMO of molecules, a direct resonant Raman scattering

Features and advantages of flexible silicon nanowires for SERS applications

• Hrvoje Gebavi,
• Vlatko Gašparić,
• Dubravko Risović,
• Nikola Baran,
• Paweł Henryk Albrycht and
• Mile Ivanda

Beilstein J. Nanotechnol. 2019, 10, 725–734, doi:10.3762/bjnano.10.72

• -sensitive and has a relatively large Raman cross section (ca. 10−29 cm2/sr [28]). The boronic acid group binds to certain analytes, for example, peptidoglycans in bacterial cell walls [29]. Recently, the difficult detection of saccharides (glucose, fructose) due to a low Raman scattering cross-section and a

Self-assembly and wetting properties of gold nanorod–CTAB molecules on HOPG

• Imtiaz Ahmad,
• Floor Derkink,
• Tim Boulogne,
• Pantelis Bampoulis,
• Harold J. W. Zandvliet,
• Hidayat Ullah Khan,
• Rahim Jan and
• E. Stefan Kooij

Beilstein J. Nanotechnol. 2019, 10, 696–705, doi:10.3762/bjnano.10.69

• ][25], catalytic [26][27][28][29], photonic [30][31][32][33][34], plasmonic [35][36][37][38][39], and surface-enhanced Raman scattering (SERS) [40][41][42] applications. In relation to our system consisting of cetyltrimethylammonium bromide (CTAB)-coated gold nanoparticles, it has also been observed

Biomimetic synthesis of Ag-coated glasswing butterfly arrays as ultra-sensitive SERS substrates for efficient trace detection of pesticides

• Guochao Shi,
• Mingli Wang,
• Yanying Zhu,
• Yuhong Wang,
• Xiaoya Yan,
• Xin Sun,
• Haijun Xu and
• Wanli Ma

Beilstein J. Nanotechnol. 2019, 10, 578–588, doi:10.3762/bjnano.10.59

• hybrids (Ag-G.b.) by magnetron sputtering technology. The 3D surface-enhanced Raman scattering (SERS) substrate is fabricated from an original chitin-based nanostructure, which serves as a bio-scaffold for Ag nanofilms to be coated on. The novel crisscrossing plate-like nanostructures of 3D Ag-G.b

• , showing its great potential application in biochemical sensing and food security. Keywords: Ag nanofilm; glasswing butterfly; pesticide; surface-enhanced Raman scattering (SERS); Introduction Surface-enhanced Raman scattering (SERS), an extension of conventional Raman spectroscopy, is a powerful

Quantification and coupling of the electromagnetic and chemical contributions in surface-enhanced Raman scattering

• Yarong Su,
• Yuanzhen Shi,
• Ping Wang,
• Jinglei Du,
• Markus B. Raschke and
• Lin Pang

Beilstein J. Nanotechnol. 2019, 10, 549–556, doi:10.3762/bjnano.10.56

• Chemistry and JILA, University of Colorado at Boulder, Boulder, Colorado 80309, USA 10.3762/bjnano.10.56 Abstract In surface-enhanced Raman scattering (SERS), both chemical (CE) and electromagnetic (EM) field effects contribute to its overall enhancement. However, neither the quantification of their

• intensity dependence of the chemical enhancement and allows for a more systematic design of SERS substrates with desired properties. Keywords: benzenethiol; chemical enhancement; physical enhancement; quantification; surface-enhanced Raman scattering (SERS); Introduction Surface-enhanced Raman scattering

• modulate the substrate polarizability, and thus enhance the Raman scattering [20][21][22]. This possible coupling effect was investigated theoretically, but not yet explored experimentally. Therefore, establishing a routine experimental procedure to separate and quantify CE and EM effects, as well as

Raman study of flash-lamp annealed aqueous Cu₂ZnSnS₄ nanocrystals

• Yevhenii Havryliuk,
• Oleksandr Selyshchev,
• Mykhailo Valakh,
• Alexandra Raevskaya,
• Oleksandr Stroyuk,
• Constance Schmidt,
• Volodymyr Dzhagan and
• Dietrich R. T. Zahn

Beilstein J. Nanotechnol. 2019, 10, 222–227, doi:10.3762/bjnano.10.20

• , up to 60 J/cm2, on NC films deposited on a glass substrate by drop-casting. The influence of film thickness and crystallinity of the initial NCs (before FLA) was also studied. Raman scattering was chosen as a main characterization method in this work, because it has already proved to be very

Controlling surface morphology and sensitivity of granular and porous silver films for surface-enhanced Raman scattering, SERS

• Sherif Okeil and
• Jörg J. Schneider

Beilstein J. Nanotechnol. 2018, 9, 2813–2831, doi:10.3762/bjnano.9.263

• the last decades [1]. This phenomenon, called surface-enhanced Raman scattering [2][3], depends on the fact that incident light leads to the excitation of surface plasmon resonances, which in turn lead to a concentration of the incident electromagnetic field thus enhancing the Raman scattering effect

Variation of the photoluminescence spectrum of InAs/GaAs heterostructures grown by ion-beam deposition

• Alexander S. Pashchenko,
• Leonid S. Lunin,
• Eleonora M. Danilina and
• Sergei N. Chebotarev

Beilstein J. Nanotechnol. 2018, 9, 2794–2801, doi:10.3762/bjnano.9.261

• phonons of bulk-like GaAs (268 cm−1) and GaBi (182 cm−1) are also observed. This indicates a change in the selection rule under Raman scattering in the InAs/GaAs system caused by lattice strain during the incorporation of Bi into the GaAs matrix. In the spectra we can clearly see the longitudinal modes of

Oriented zinc oxide nanorods: A novel saturable absorber for lasers in the near-infrared

• Pavel Loiko,
• Tanujjal Bora,
• Josep Maria Serres,
• Haohai Yu,
• Magdalena Aguiló,
• Francesc Díaz,
• Uwe Griebner,
• Valentin Petrov,
• Xavier Mateos and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2018, 9, 2730–2740, doi:10.3762/bjnano.9.255

• orientation of the nanorods along the [001] crystallographic axis. No notable variation in the XRD patterns of the NRs was observed with respect to growth time. The Raman spectra of the ZnO NRs are shown in Figure 2b, where a strong Raman scattering at 435 cm−1 representing the E2high phonon mode of ZnO is

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

• if excited at energies below the sp/d interband transition. Enhanced inelastic electron tunneling through the gap seems to be the origin of photon emission [52][55], leading to electronic Raman scattering (ERS) of the laser photons [53] which is at the origin of the background observed in TERS and

• Line 1.1- Action 1.1.2) and the European Community within the EuroNanoMed3 ERANET cofund (H2020) project “Surface-enhanced Raman scattering with nanophotonic and biomedical amplifying systems for an early diagnosis of Alzheimer’s disease pathology SPEEDY” (ID 221).

Disorder in H⁺-irradiated HOPG: effect of impinging energy and dose on Raman D-band splitting and surface topography

• Lisandro Venosta,
• Noelia Bajales,
• Sergio Suárez and
• Paula G. Bercoff

Beilstein J. Nanotechnol. 2018, 9, 2708–2717, doi:10.3762/bjnano.9.253

• -resonance Raman scattering processes that originate in electronic π–π* transitions [5][8][9][31][32][33]. Thus, the generation of structural defects induced by H+ at different doses and energies becomes evident in our experiments. It is accepted that the D band involves a double-resonance process that

SERS active Ag–SiO₂ nanoparticles obtained by laser ablation of silver in colloidal silica

• Cristina Gellini,
• Francesco Muniz-Miranda,
• Alfonso Pedone and
• Maurizio Muniz-Miranda

Beilstein J. Nanotechnol. 2018, 9, 2396–2404, doi:10.3762/bjnano.9.224

• examined by UV–vis absorption spectroscopy, transmission electron microscopy and Raman spectroscopy. The surface enhanced Raman scattering (SERS) activity of these nanocomposites was tested using 2,2’-bipyridine as a molecular reporter and excitation in the visible and near-IR spectral regions. The

• of the present work is to apply laser ablation to the fabrication of new materials for surface enhanced Raman scattering (SERS) [15][16], focusing on silver and silica nanoparticles in aqueous suspension. This research was undertaken for three main reasons. The first is that silver nanoparticles that