Morphology-driven gas sensing by fabricated fractals: A review

• Vishal Kamathe and
• Rupali Nagar

Beilstein J. Nanotechnol. 2021, 12, 1187–1208, doi:10.3762/bjnano.12.88

• experimental approaches. Here, lithography techniques can be implemented to write fractals of different fractal dimensions and their response under identical test conditions can be studied. Such structures can also be explored as substrates for surface-enhanced Raman spectroscopy, which finds applications in

The effect of cobalt on morphology, structure, and ORR activity of electrospun carbon fibre mats in aqueous alkaline environments

• Markus Gehring,
• Tobias Kutsch,
• Osmane Camara,
• Alexandre Merlen,
• Hermann Tempel,
• Hans Kungl and
• Rüdiger-A. Eichel

Beilstein J. Nanotechnol. 2021, 12, 1173–1186, doi:10.3762/bjnano.12.87

• fibres. In this study, cobalt-decorated fibres are prepared, and the influence of carbonisation temperature on the resulting particle decoration, as well as on fibre structure and morphology is discussed. Scanning electron microscopy, Raman spectroscopy, X-ray diffraction, X-ray photoelectron

• electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, elemental analysis, and inductively coupled plasma optical emission spectrometry (ICP-OES). In addition, the fibres were analysed in terms of their

• only in the binding energy range from 770 to 795 eV. Raman spectra were obtained using a Bruker Senterra at room temperature in ambient atmosphere. The excitation wavelength was 532 nm with a power of 2 mW. The signals of two subsequent measurements of 30 s each were added up, to improve the signal-to

Molecular assemblies on surfaces: towards physical and electronic decoupling of organic molecules

• Sabine Maier and
• Meike Stöhr

Beilstein J. Nanotechnol. 2021, 12, 950–956, doi:10.3762/bjnano.12.71

• significant enhancement of the excited-state spin lifetimes [62]. Concerning optical properties, successful decoupling made the examination of fluorescence from both single molecules and molecular assemblies feasible by tunneling electron excitation [19][63][64][65][66]. Also, sub-molecularly resolved Raman

The role of deep eutectic solvents and carrageenan in synthesizing biocompatible anisotropic metal nanoparticles

• Nabojit Das,
• Akash Kumar and
• Raja Gopal Rayavarapu

Beilstein J. Nanotechnol. 2021, 12, 924–938, doi:10.3762/bjnano.12.69

• -enhanced Raman scattering (SERS) when doped with rhodamine B (RhB). The enhancement factor produced by these gold nanoflowers was estimated to be 1.09 × 105 regarding pure RhB. The value of the enhancement factor is up to par with the intensively branched gold nanoparticles and is even greater than some of

Modification of a SERS-active Ag surface to promote adsorption of charged analytes: effect of Cu²⁺ ions

• Bahdan V. Ranishenka,
• Andrei Yu. Panarin,
• Irina A. Chelnokova,
• Sergei N. Terekhov,
• Peter Mojzes and
• Vadim V. Shmanai

Beilstein J. Nanotechnol. 2021, 12, 902–912, doi:10.3762/bjnano.12.67

• the electrostatic interaction between analyte molecules and silver nanoparticles (Ag NPs) on the intensity of surface-enhanced Raman scattering (SERS). For this, we fabricated nanostructured plasmonic films by immobilization of Ag NPs on glass plates and functionalized them by a set of differently

• ; oligonucleotides; porphyrin; silver nanoparticles; substrate modification; surface-enhanced Raman spectroscopy (SERS); Introduction Surface-enhanced Raman scattering (SERS) with its advantages of extreme sensitivity, high selectivity, and non-destructive nature has demonstrated great potential for the quick

• even technical tasks need to be solved for practical applications of the method [2][3][4]. Raman signal surface enhancement uses so-called SERS-active substrates that are mainly inorganic or hybrid nanostructured materials. Significant attention has been devoted to the development of formation methods

A review of defect engineering, ion implantation, and nanofabrication using the helium ion microscope

• Frances I. Allen

Beilstein J. Nanotechnol. 2021, 12, 633–664, doi:10.3762/bjnano.12.52

• 0.2–1.3%) and, within this dose range, measured a metal–insulator transition [19]. Raman analysis showed that even at the highest dose (i.e., for strongly insulating graphene), the crystal lattice structure of the graphene sheet was essentially preserved. A subsequent study by Moktadir et al

• Klein et al., the effects of ion dose on the optical and valleytronic properties of the material were investigated [36]. In this study, Raman spectroscopy was used to systematically probe the effect of increasing disorder for increasing irradiation dose, and the corresponding distance between the ion

• demonstrated, using localized helium ion irradiation followed by encapsulation in hBN in order to enhance the optical quality of the defect states [34]. Results from this study are shown in Figure 2g. A recent study of the effect of helium ion-induced disorder on the Raman modes and photoluminscence behavior

Properties of graphene deposited on GaN nanowires: influence of nanowire roughness, self-induced nanogating and defects

• Jakub Kierdaszuk,
• Piotr Kaźmierczak,
• Justyna Grzonka,
• Aleksandra Krajewska,
• Aleksandra Przewłoka,
• Wawrzyniec Kaszub,
• Zbigniew R. Zytkiewicz,
• Marta Sobanska,
• Maria Kamińska,
• Andrzej Wysmołek and
• Aneta Drabińska

Beilstein J. Nanotechnol. 2021, 12, 566–577, doi:10.3762/bjnano.12.47

• Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668, Warsaw, Poland 10.3762/bjnano.12.47 Abstract We present detailed Raman studies of graphene deposited on gallium nitride nanowires with different variations in height. Our results indicate that different density and height of

• nanowires impact graphene properties such as roughness, strain, and carrier concentration as well as density and type of induced defects. Tracing the manifestation of those interactions is important for the application of novel heterostructures. A detailed analysis of Raman spectra of graphene deposited on

• engineering. Keywords: carrier concentration; gallium nitride; graphene; nanowires; Raman spectroscopy; scattering on defects; strain; Introduction The combination of excellent electrical and mechanical properties with interesting physical phenomena occurring in two-dimensional structures makes graphene an

On the stability of microwave-fabricated SERS substrates – chemical and morphological considerations

• Limin Wang,
• Aisha Adebola Womiloju,
• Christiane Höppener,
• Ulrich S. Schubert and
• Stephanie Hoeppener

Beilstein J. Nanotechnol. 2021, 12, 541–551, doi:10.3762/bjnano.12.44

• , Philosophenweg 7, 07743 Jena, Germany Leibniz-Institut of Photonic Technology e.V. (IPHT), Albert-Einstein-Straße 9, 07745 Jena, Germany Institute of Physical Chemistry, Friedrich Schiller University Jena, Lessingstr. 10, 07743 Jena, Germany 10.3762/bjnano.12.44 Abstract The stability of surface-enhanced Raman

• substrates treated with methanol, ethanol, or N,N-dimethylformamide (DMF) were comparable and showed overall good stability and did not show severe morphological changes or a strong decrease in their Raman activity. Toluene treatment resulted in a strong decrease in the Raman activity whereas dimethyl

• sulfoxide (DMSO) treatment completely preserved or even slightly improved the Raman enhancement capabilities. SERS substrates immersed into phosphate-buffered saline (PBS) solutions were observed to be rather instable in low and neutral pH buffer solutions. Other buffer systems showed less severe influences

Surface-enhanced Raman scattering of water in aqueous dispersions of silver nanoparticles

• Paulina Filipczak,
• Krzysztof Hałagan,
• Jacek Ulański and
• Marcin Kozanecki

Beilstein J. Nanotechnol. 2021, 12, 497–506, doi:10.3762/bjnano.12.40

• Paulina Filipczak Krzysztof Halagan Jacek Ulanski Marcin Kozanecki Department of Molecular Physics, Faculty of Chemistry, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland 10.3762/bjnano.12.40 Abstract The resonance Raman effect (RRE) is a phenomenon which results in a strong

• selective enhancement of Raman signals from the samples. Previous studies showed that the RRE in liquid water directly corresponds to its supramolecular structure. It was also reported that the electric-field-induced orientation of water molecules on the electrode surface results in the surface-enhanced

• Raman scattering (SERS) effect. In this work, we show the SERS effect for water molecules in the dispersion of silver nanoparticles (AgNPs) without any external electrical field. An enhancement factor was estimated to be (4.8 ± 0.8) × 106 for an excitation wavelength of 514.5 nm and for AgNPs with an

A review on nanostructured silver as a basic ingredient in medicine: physicochemical parameters and characterization

• Gabriel M. Misirli,
• Kishore Sridharan and
• Shirley M. P. Abrantes

Beilstein J. Nanotechnol. 2021, 12, 440–461, doi:10.3762/bjnano.12.36

• ], Copyright 2005 American Chemical Society B; part C was reprinted from [39], Chemical Physics Letters, vol. 427, by J. M. McLellan, A. Siekkinen, J. Chen, Y. Xia, Comparison of the surface-enhanced Raman scattering on sharp and truncated silver nanocubes, 122–126, Copyright (2006), with permission from

Solution combustion synthesis of a nanometer-scale Co₃O₄ anode material for Li-ion batteries

• Monika Michalska,
• Huajun Xu,
• Qingmin Shan,
• Shiqiang Zhang,
• Yohan Dall'Agnese,
• Yu Gao,
• Amrita Jain and
• Marcin Krajewski

Beilstein J. Nanotechnol. 2021, 12, 424–431, doi:10.3762/bjnano.12.34

• Raman spectroscopy (RS) measurements. The experimental results from both techniques are shown in Figure 1 and they are complementary. The XRD pattern presented in Figure 1a reveals seven peaks located at 19°, 31.3°, 36.8°, 38.7°, 44.8°, 55.8°, and 59.4°, which correspond to the (111), (220), (311), (222

• broadening yielded an estimated average crystallite size of about 40 nm, according to the Scherrer formula. The Raman spectrum shown in Figure 1b exhibits five bands located at 184, 464, 506, 601, and 670 cm−1, corresponding to the F2g3, Eg, F2g2, F2g1, and A1g active vibrational modes, respectively [5][10

• Raman spectroscopy (RS). XRD data was acquired using a SIEMENS D500 diffractometer equipped with a Cu Kα (λXRD = 1.542 Å) radiation source. The room-temperature XRD pattern in the range of 15° ≤ 2θ ≤ 60° was collected with a step size of 0.002° and an acquisition time of 3 s per step. The RS experiments

Nickel nanoparticle-decorated reduced graphene oxide/WO₃ nanocomposite – a promising candidate for gas sensing

• Ilka Simon,
• Alexandr Savitsky,
• Rolf Mülhaupt,
• Vladimir Pankov and
• Christoph Janiak

Beilstein J. Nanotechnol. 2021, 12, 343–353, doi:10.3762/bjnano.12.28

• using XPS and Raman spectroscopy. Such bonds can play an important role also in our case with regard to charge transfer. It has been established that adsorption of NO2 molecules will cause upward band bending by capturing free electrons from the conduction band and shift the Fermi level of WO3 away from

Scanning transmission helium ion microscopy on carbon nanomembranes

• Daniel Emmrich,
• Annalena Wolff,
• Nikolaus Meyerbröker,
• Jörg K. N. Lindner,
• André Beyer and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2021, 12, 222–231, doi:10.3762/bjnano.12.18

• , HIM and Raman spectroscopy were performed on the samples after the EFTEM experiments. The SE image in Figure 7b shows that membrane turned brighter in the areas previously imaged with EFTEM, which is indicative of a higher electric conductivity, as demonstrated in the following. In Figure 7c, a Raman

• ). After the area was exposed to the beam for 3 min, the area turned conductive as the bright signal in SE imaging indicates. (c) Raman measurement on the indicated area in (b) and a reference spectrum of a freestanding, non-irradiated area on the same sample. After irradiation the photoluminescence

Paper-based triboelectric nanogenerators and their applications: a review

• Jing Han,
• Nuo Xu,
• Yuchen Liang,
• Mei Ding,
• Junyi Zhai,
• Qijun Sun and
• Zhong Lin Wang

Beilstein J. Nanotechnol. 2021, 12, 151–171, doi:10.3762/bjnano.12.12

• layer and PDMS as the negative friction layer. The modified CNTs embedded into a thin layer of PANI by the TENG electrochemical system showed a larger diameter compared with the pristine CNTs, as shown in Figure 10b. The electropolymerization of PANI on a CNT electrode is also identified by the Raman

A review on the green and sustainable synthesis of silver nanoparticles and one-dimensional silver nanostructures

• Sina Kaabipour and
• Shohreh Hemmati

Beilstein J. Nanotechnol. 2021, 12, 102–136, doi:10.3762/bjnano.12.9

• resonance (SPR) and generally have a broad absorption spectrum [83]. This enables applications in optoelectronics and surface-enhanced Raman scattering [84][85]. AgNPs were also applied effectively in solar cell matrices [32][86][87]. AgNPs can enhance the current density in solar cells due to their far

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

• 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

ZnO and MXenes as electrode materials for supercapacitor devices

• Ameen Uddin Ammar,
• Ipek Deniz Yildirim,
• Feray Bakan and
• Emre Erdem

Beilstein J. Nanotechnol. 2021, 12, 49–57, doi:10.3762/bjnano.12.4

• environment of the lattice atoms and defects. With the aid of advanced characterization techniques one may get valuable information on site symmetry, atomic bonding, and, in particular, on the bandgap energy of semiconductors. Raman, photoluminescence (PL), UV–vis, and electron paramagnetic resonance (EPR

• the existence of the defects. Owing to the extreme sensitivity of EPR spectroscopy (1011 spins/g) to paramagnetically active defect centers, one may correlate the information on the local electronic configuration from EPR spectra with Raman and PL spectra. Thus, when such semiconductor materials are

• , which is expected due to the quantum confinement effect [13]. Another crucially important optical characterization technique for the investigation of defects is Raman spectroscopy. The phonon vibration modes are highly sensitive to the existence of point defects, which are reflected in distinct spectral

Towards 3D self-assembled rolled multiwall carbon nanotube structures by spontaneous peel off

• Jonathan Quinson

Beilstein J. Nanotechnol. 2020, 11, 1865–1872, doi:10.3762/bjnano.11.168

• [16][24][25]. It is also in agreement with the Raman characterization detailed below. The SEM analysis reveals that the peeled-off layers are C1/N2 sections detached from another supporting C3/N4 MWCNT layer. This implies that only a few layers of MWCNTs are disconnected from the forest. Such peeling

• , there is a wavy, a straight, and another wavy section. This sequential changes in the morphology is in agreement with the synthesis sequence used. The interface between the expected N2 and C3 sections is marked by a brighter line. Raman spectra of undoped MWCNTs and nitrogen-doped MWCNTs are

• (relative to the D peak intensity) and the presence of a 2D peak indicate a more graphitized MWCNT. Conveniently, the structures obtained here have sections that are long enough (>10 μm) to be unambiguously focused by a Raman laser, using the optical lens of a Raman microscope [16]. Typical Raman spectra

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

• thickness range. In contrast, tip-enhanced Raman spectroscopy measurements on edges in folded graphene flakes, 14 layers thick, show no significant strain. This indicates that layers in graphene flakes, up to 5 nm thick, can still slip to relieve stress, showing the richness of the effect in 2D systems. The

• methods; atomic force microscopy (AFM); molecular dynamics (MD); Raman spectroscopy; nanostructured materials; Introduction Layered materials such as graphite, talc, and transition metal dichalcogenides (TMDs), held together by strong covalent bonds within layers and relatively weak van der Waals

• 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

The influence of an interfacial hBN layer on the fluorescence of an organic molecule

• Christine Brülke,
• Oliver Bauer and
• Moritz M. Sokolowski

Beilstein J. Nanotechnol. 2020, 11, 1663–1684, doi:10.3762/bjnano.11.149

• organic molecule 3,4,9,10-perylene tetracarboxylic dianhydride (PTCDA) from the supporting Cu(111) surface by Raman and fluorescence (FL) spectroscopy. The Raman fingerprint-type spectrum of PTCDA served as a monitor for the presence of molecules on the surface. Several broad and weak FL lines between

• -perylene tetracarboxylic dianhydride (PTCDA); Raman spectroscopy; Introduction In recent years, two-dimensional materials (2DMs) have been established as a highly interesting field of studies, both in regard to their fundamental physical properties as well as their potential for technical applications [1

• the Cu(111) substrate. In this contribution, we will discuss Raman modes and several different FL lines of PTCDA that were observed on both hBN/Cu(111) and Cu(111). For an effective comparison, the structures and the growth modes of the PTCDA layers are relevant. Details of the structural

High-responsivity hybrid α-Ag₂S/Si photodetector prepared by pulsed laser ablation in liquid

• Raid A. Ismail,
• Hanan A. Rawdhan and
• Duha S. Ahmed

Beilstein J. Nanotechnol. 2020, 11, 1596–1607, doi:10.3762/bjnano.11.142

• with a monoclinic structure and that crystallinity of the nanoparticles was improved after adding CTAB. Raman studies revealed the presence of peaks related to Ag–S bonds (Ag modes) and the longitudinal optical phonon 2LO mode. Scanning electron microscopy investigations confirmed the production of

• , Shimadzu) was employed to estimate the chemical composition of the Ag2S NPs. The morphology and size of the nanocrystals were examined via transmission electron microscopy (TEM; EM208, Philips). Raman spectroscopy was performed on colloidal Ag2S and thiourea solution using a Raman spectrometer (Bruker

• reported data [24]. Figure 4 shows the Raman spectra of Ag2S NPs synthesized in Tu solution with and without CTAB. Four vibration modes were assigned to Ag2S. The peaks at 45 and 65 cm−1 are related to Ag–S bonds (Ag modes) [25]. The third peak at 480 cm−1 was indexed to the longitudinal optical phonon 2LO

Fabrication of nano/microstructures for SERS substrates using an electrochemical method

• Jingran Zhang,
• Tianqi Jia,
• Xiaoping Li,
• Junjie Yang,
• Zhengkai Li,
• Guangfeng Shi,
• Xinming Zhang and
• Zuobin Wang

Beilstein J. Nanotechnol. 2020, 11, 1568–1576, doi:10.3762/bjnano.11.139

• electrochemical method, three-dimensional arrayed nanopore structures are machined onto a Mg surface. The structured Mg surface is coated with a thin gold (Au) film, which is used as a surface-enhanced Raman scattering (SERS) substrate. A rhodamine 6G (R6G) probe molecule is used as the detection agent for the

• SERS measurement. Different sizes of arrayed micro/nanostructures are fabricated by different treatment time using the electrochemical process. The topographies of these micro/nanostructures and the thickness of the Au film have an influence on the Raman intensity of the Mg substrate. Furthermore, when

• the thickness of Au film coating is held constant, the Raman intensity on the structured Mg substrates is about five times higher after a treatment time of 1 min when compared with other treatment times. The SERS enhancement factor ranges from 106 to 1.75 × 107 under these experimental conditions

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

• , Germany 10.3762/bjnano.11.136 Keywords: active plasmonics; electrically driven nanoantenna; gap antenna; nanoantenna; nanofabrication; nanospectroscopy; nano-photonics; optical antenna; second harmonic generation; sensing; scanning tip; surface-enhanced infrared absorption (SEIRA); surface-enhanced Raman

• 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

• configurations with increasing control over their optical performance [1][2][3][4]. The strong local near-field enhancement by plasmonic nanoantennas is being harnessed for high sensitivity, high-resolution optical nanospectroscopy techniques [5], such as surface-enhanced or tip-enhanced Raman spectroscopy (SERS

One-step synthesis of carbon-supported electrocatalysts

• Sebastian Tigges,
• Nicolas Wöhrl,
• Ivan Radev,
• Ulrich Hagemann,
• Markus Heidelmann,
• Thai Binh Nguyen,
• Stanislav Gorelkov,
• Stephan Schulz and
• Axel Lorke

Beilstein J. Nanotechnol. 2020, 11, 1419–1431, doi:10.3762/bjnano.11.126

• amorphous layer (Ar/H2 ≈59, Figure 4d, right panel). Raman spectroscopy was performed to determine the quality (defect density, defect type, and hybridization) of the deposited Pt/CNW layers. All samples produced at sufficiently high pressures and low carrier gas flow rates exhibit the typical spectrum

• indicates 100% sp²-hybridization [31]. No peaks are found for the Pt-NPs in the investigated wavenumber region, which is supported by a study of Kimata et al. [32]. A more detailed evaluation of the Raman data can be found in Supporting Information File 1. Controlling the physical properties of the active

• Information File 1). Characterization The morphology of the resulting samples was investigated using a scanning electron microscope (SEM; Inspect F and Helios 600 NanoLab DualBeam, FEI Deutschland GmbH). Raman spectroscopy was performed with green laser excitation (532 nm) in a Renishaw confocal inVia Raman

Transient coating of γ-Fe₂O₃ nanoparticles with glutamate for its delivery to and removal from brain nerve terminals

• Konstantin Paliienko,
• Artem Pastukhov,
• Michal Babič,
• Daniel Horák,
• Olga Vasylchenko and
• Tatiana Borisova

Beilstein J. Nanotechnol. 2020, 11, 1381–1393, doi:10.3762/bjnano.11.122

• the ligands. Raman and FTIR spectroscopy measurements showed that glutamate and aspartate salts were adsorbed at the surface of γ-Fe2O3 nanoparticles [20]. It should be noted that the methodological protocol of above experiments on glutamate and aspartate chemisorption suggested the use of bio