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

• synthesized material were investigated using electron diffraction, Raman spectroscopy, and transmission electron microscopy. It was shown that the morphology of the reaction product strongly depends on the amount of OH− ions in the reaction mixture, varying from Fe3O4 nanorods to spherical Fe3O4 nanoparticles

• 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

• have very different vibrational bands [46][47]. The Raman spectrum of the sample synthesized at R = 2.1 is shown in Figure 6 (blue curve). The data shows that the main band (672 cm−1) coincides with the main vibrational mode of magnetite (A1g) [48][49], thus proving that Fe3O4 nanoparticles were

Gas sorption porosimetry for the evaluation of hard carbons as anodes for Li- and Na-ion batteries

• Yuko Matsukawa,
• Fabian Linsenmann,
• Maximilian A. Plass,
• George Hasegawa,
• Katsuro Hayashi and
• Tim-Patrick Fellinger

Beilstein J. Nanotechnol. 2020, 11, 1217–1229, doi:10.3762/bjnano.11.106

• (002) reflection of the HTs corresponds to large interlayer distances in the range of 0.4 nm, while the RF carbons show d-spacings of 0.43 and 0.39 nm. Raman spectra of HT2 shows the G band peak at ca. 1590 cm−1 and in addition the D band peak at ca. 1340 cm−1, which is further pointing to a disordered

• carbonized at 1000 or 1600 °C for 2 h in a stream of argon gas (1 L min−1). The carbon samples derived from RF gels (RF carbons) were labeled with the carbonization temperature, namely RF-1000 and RF-1600. Characterization Powder X-ray diffraction (XRD) measurements and Raman spectroscopy were employed to

• confirm that the samples had an amorphous carbon structure, using an X-ray diffractometer (X'Pert Pro, PANalytical, Netherlands, using Cu Kα radiation with a generator voltage of 45 kV and a tube current of 40 mA) and a Raman spectrometer (Jubin-Yvon iHR550, HORIBA, Japan, equipped with a Laser Quantum

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

• , Germany 10.3762/bjnano.11.99 Abstract Tip-enhanced Raman spectroscopy is combined with polarization angle-resolved spectroscopy to investigate the nanometer-scale structural properties of core–shell silicon nanowires (crystalline Si core and amorphous Si shell), which were synthesized by platinum

• of the Raman peaks of crystalline Si and amorphous Si by applying tip-enhanced Raman spectroscopy, at sample positions being 8 nm apart. The local crystallinity revealed using confocal Raman spectroscopy and tip-enhanced Raman spectroscopy agrees well with the high-resolution transmission electron

• 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

Photothermally active nanoparticles as a promising tool for eliminating bacteria and biofilms

• Mykola Borzenkov,
• Piersandro Pallavicini,
• Angelo Taglietti,
• Laura D’Alfonso,
• Maddalena Collini and
• Giuseppe Chirico

Beilstein J. Nanotechnol. 2020, 11, 1134–1146, doi:10.3762/bjnano.11.98

• nanoparticles) were developed to rapidly detect and inhibit pathogenic microorganisms [59]. By using the label-free surface-enhanced Raman spectroscopy technique, the authors demonstrated that the optical fingerprints can be used to sense bacterial cell molecular structures and to promote recyclable

Applications of superparamagnetic iron oxide nanoparticles in drug and therapeutic delivery, and biotechnological advancements

• Maria Suciu,
• Corina M. Ionescu,
• Alexandra Ciorita,
• Septimiu C. Tripon,
• Dragos Nica,
• Hani Al-Salami and
• Lucian Barbu-Tudoran

Beilstein J. Nanotechnol. 2020, 11, 1092–1109, doi:10.3762/bjnano.11.94

• microscopy (EM), iron oxide magnetic beads for the separation of cells and molecules, gold and silver nanoparticles as fiducials for EM, for immuno-EM labeling and surface-enhanced Raman spectroscopy, or for gene transfection, liposomes for drug delivery, and gadolinium or iron oxide nanoparticles for

A few-layer graphene/chlorin e6 hybrid nanomaterial and its application in photodynamic therapy against Candida albicans

• Selene Acosta,
• Carlos Moreno-Aguilar,
• Dania Hernández-Sánchez,
• Beatriz Morales-Cruzado,
• Erick Sarmiento-Gomez,
• Carla Bittencourt,
• Luis Octavio Sánchez-Vargas and
• Mildred Quintana

Beilstein J. Nanotechnol. 2020, 11, 1054–1061, doi:10.3762/bjnano.11.90

• nanomaterial in water. The Raman spectra of the hybrid nanomaterial, Ce6 and graphite are shown in Figure 1b for comparison. The highest peak, corresponding to the G band (≈1580 cm−1), was used to normalize the signals in each case. The 2D band (≈2715 cm−1) gives information about π–π stacking which only

• occurs in graphite. The intensity of the 2D band is reduced in the FLG-Ce6 hybrid nanomaterial due to the interaction between FLG and Ce6 π-electrons. Finally, the D band (≈1350 cm−1) is not present in the Raman spectrum of pristine graphite as it gives information about the in-plane defects of the

• graphene lattice. In the Raman spectrum of the FLG-Ce6 hybrid nanomaterial, the D band is overshadowed by the Raman signals of Ce6. Figure 1c shows the X-ray photoelectron spectroscopy (XPS) spectra of the hybrid nanomaterial and Ce6. The O 1s core level spectrum of the hybrid nanomaterial FLG-Ce6 is

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

Integrated photonics multi-waveguide devices for optical trapping and Raman spectroscopy: design, fabrication and performance demonstration

• Gyllion B. Loozen,
• Arnica Karuna,
• Mohammad M. R. Fanood,
• Erik Schreuder and
• Jacob Caro

Beilstein J. Nanotechnol. 2020, 11, 829–842, doi:10.3762/bjnano.11.68

• International B.V., P.O. Box 456, 7500 AL, Enschede, Netherlands 10.3762/bjnano.11.68 Abstract We realized integrated photonics multi-waveguide devices for optical trapping and Raman spectroscopy of particles in a fluid. In these devices, multiple beams directed towards the device center lead to a local field

• the influence of surfaces. We report the design (including simulations), fabrication and performance demonstration for multi-waveguide devices, using our Si3N4 waveguiding platform as the basis. The designed ridge waveguides, optimized for trapping and Raman spectroscopy, emit narrow beams. Multiple

• focused Gaussian beam traps and are confirmed by our own simulations. The Raman spectra of the beads (in this work measured via an objective) show clear peaks that are characteristic of polystyrene. In the low-wavenumber range, the spectra have a background that most likely originates from the Si3N4

Templating effect of single-layer graphene supported by an insulating substrate on the molecular orientation of lead phthalocyanine

• K. Priya Madhuri,
• Abhay A. Sagade,
• Pralay K. Santra and
• Neena S. John

Beilstein J. Nanotechnol. 2020, 11, 814–820, doi:10.3762/bjnano.11.66

• K. Priya Madhuri Abhay A. Sagade Pralay K. Santra Neena S. John Centre for Nano and Soft Matter Sciences, Jalahalli, Bengaluru 560 013, India Laboratory for Advanced Nanoelectronic Devices, Sir C. V. Raman Research Park, Department of Physics & Nanotechnology, SRM Institute of Science and

• of PbPc on graphene revealing interconnected highly conducting domains. Results and Discussion The Raman spectrum of CVD-grown single-layer graphene transferred onto a SiO2/Si substrate (referred to as SLG/SiO2/Si hereafter) is presented in Figure 2. A sharp and strong peak at 2680 cm−1 corresponds

• (111), Si and SiO2. Detailed studies using Raman spectroscopy and 2D-GIXRD show ordered monoclinic and triclinic moieties on HOPG and Si substrates, respectively, while the Au(111) surface gives rise to disordered fractions due to the absence of long-range ordering [9][26]. In the present study, the

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

• of Electrical and Computer Engineering, University of Texas, El Paso, TX 79968, United States 10.3762/bjnano.11.63 Abstract Phonon dynamics is explored in mechanically exfoliated two-dimensional WSe2 using temperature-dependent and laser-power-dependent Raman and photoluminescence (PL) spectroscopy

• . From this analysis, phonon lifetime in the Raman active modes and phonon concentration, as correlated to the energy parameter E0, were calculated as a function of the laser power, P, and substrate temperature, T. For monolayer WSe2, from the power dependence it was determined that the phonon lifetime

• electronic, optoelectronic and thermoelectric devices in the future. Keywords: phonon concentration; phonon lifetime; Raman spectroscopy; thermal coefficients; Tungsten diselenide; two-dimensional material; Introduction Since the discovery of graphene, atomically thin two-dimensional layered materials have

Hexagonal boron nitride: a review of the emerging material platform for single-photon sources and the spin–photon interface

• Stefania Castelletto,
• Faraz A. Inam,
• Shin-ichiro Sato and
• Alberto Boretti

Beilstein J. Nanotechnol. 2020, 11, 740–769, doi:10.3762/bjnano.11.61

Exfoliation in a low boiling point solvent and electrochemical applications of MoO₃

• Matangi Sricharan,
• Bikesh Gupta,
• Sreejesh Moolayadukkam and
• H. S. S. Ramakrishna Matte

Beilstein J. Nanotechnol. 2020, 11, 662–670, doi:10.3762/bjnano.11.52

• (AFM; Agilent 5500). Samples for FESEM and AFM were prepared by dripping 10 µL of MoO3 dispersion (diluted 100 times) onto a Si/SiO2 (300 nm) substrate while samples for TEM were prepared by dripping 10 µL of the diluted dispersion on a 300 mesh lacey carbon grid. Raman spectra (Horiba LABRam HR) of

• + in the presence of UV light. This was further confirmed using Raman spectroscopy and UV–vis spectroscopy (Supporting Information File 1, Figure S5). The Raman spectra of bulk and exfoliated MoO3 in 2-butanone, IPA and an IPA/H2O mixture are shown in Figure 2e. Bulk and exfoliated MoO3 in 2-butanone

• has strong Raman peaks at 278, 334, 662, 816 and 992 cm−1, which are in good agreement with orthorhombic α-MoO3, suggesting that the exfoliated MoO3 retained its chemical structure [13]. Additionally, the increase in full width at half maximum (FWHM) from 4 cm−1 (bulk) to 8 cm−1 (exfoliated in 2

Silver-decorated gel-shell nanobeads: physicochemical characterization and evaluation of antibacterial properties

• Marta Bartel,
• Katarzyna Markowska,
• Marcin Strawski,
• Krystyna Wolska and
• Maciej Mazur

Beilstein J. Nanotechnol. 2020, 11, 620–630, doi:10.3762/bjnano.11.49

• [10][11][12][13][14][15][16][17]. The resulting composites exhibit a double function, they support the metal nanoparticles and prevent their aggregation. For example, polystyrene microspheres have been decorated with silver nanoparticles and were used as catalysts, Raman-enhancing materials

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

Adsorptive removal of bulky dye molecules from water with mesoporous polyaniline-derived carbon

• Hyung Jun An,
• Jong Min Park,
• Nazmul Abedin Khan and
• Sung Hwa Jhung

Beilstein J. Nanotechnol. 2020, 11, 597–605, doi:10.3762/bjnano.11.47

• on the enrichment of carbon (or successive removal of heteroatoms such as nitrogen and oxygen) with increasing pyrolysis temperature [42][43]. The best adsorbent (vide infra) KOH-900 was analyzed further with Raman spectroscopy. As shown in Supporting Information File 1, Figure S1, KOH-900 is

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

Nanoarchitectonics: bottom-up creation of functional materials and systems

• Katsuhiko Ariga

Beilstein J. Nanotechnol. 2020, 11, 450–452, doi:10.3762/bjnano.11.36

• TiO2 and ZnO nanoparticles exhibit distinct and useful properties [35]. Other examples include a self-assembled MoS2-based composite that was developed for energy conversion and storage purposes [36], a silver-nanoparticle/cellulose-nanofiber composite that was applied for surface-enhanced Raman

Electrochemically derived functionalized graphene for bulk production of hydrogen peroxide

• Munaiah Yeddala,
• Pallavi Thakur,
• Anugraha A and
• Tharangattu N. Narayanan

Beilstein J. Nanotechnol. 2020, 11, 432–442, doi:10.3762/bjnano.11.34

• (see Figure 2a). In order to test the durability of the materials in acidic medium, chronoamperometry studies were carried out in 0.5 M H2SO4 at 0.45 V vs RHE for 3 h. The EEG samples were studied (before and after chronoamperometry) using Raman and FTIR spectroscopy along with the electrochemical

• performance in 0.1 M KOH solution, and the data is given in Figure 5. In Figure 5a, the Raman spectra of EEG before and after 3 h of chronoamperometry are shown, which show no appreciable change in either the peak position or peak intensity. This indicates that no additional defects are created during the

• experiment. The important Raman peaks are marked in the figure and the shoulder peak in “G” is due to the additional single phonon intra-valley scattering process (named as D’) which is due to the presence of defects. However, the FTIR spectrum (see Figure S4b) shows evidence for the formation of OH

Formation of nanoripples on ZnO flat substrates and nanorods by gas cluster ion bombardment

• Xiaomei Zeng,
• Vasiliy Pelenovich,
• Bin Xing,
• Rakhim Rakhimov,
• Wenbin Zuo,
• Alexander Tolstogouzov,
• Chuansheng Liu,
• Dejun Fu and
• Xiangheng Xiao

Beilstein J. Nanotechnol. 2020, 11, 383–390, doi:10.3762/bjnano.11.29

• -enhanced Raman spectroscopy [4]. Ion beam formation of nanoscale ripples has emerged as a versatile method to imprint uniaxial magnetic anisotropy [5] and to control the magnetic texture of thin films [6]. Formation of self-assembled surface nanoripple structures by monoatomic off-normal ion irradiation

An advanced structural characterization of templated meso-macroporous carbon monoliths by small- and wide-angle scattering techniques

• Felix M. Badaczewski,
• Marc O. Loeh,
• Torben Pfaff,
• Dirk Wallacher,
• Daniel Clemens and
• Bernd M. Smarsly

Beilstein J. Nanotechnol. 2020, 11, 310–322, doi:10.3762/bjnano.11.23

• obtained from only the SANS analysis of the empty and DPX-filled samples. Here the non-accessibility (black) is much more pronounced. The available surface area for DPX adsorption is less than 50% for all carbon samples. Microstructural characterization Figure 6 depicts the Raman raw data of the monolithic

• with regard to the relationship between meso- and macroporosity and the sp2-hybridized atomic structure, the latter being determined by the carbon source. Based on porosity analysis (Hg porosimetry and physisorption), small-angle neutron scattering, wide-angle X-ray scattering and Raman spectroscopy we

• (empty samples) (SPhys.,Ar/SSANS,empty). (B) Ratios based only on SANS analysis of the empty and DPX-filled carbon samples (SSANS,filled/SSANS,empty). Raman data, WAXS data and fits (lines) of the WAXS data (open circles). Microstructural parameters describing the size and disorder of graphene-like

Rational design of block copolymer self-assemblies in photodynamic therapy

• Maxime Demazeau,
• Laure Gibot,
• Anne-Françoise Mingotaud,
• Patricia Vicendo,
• Clément Roux and
• Barbara Lonetti

Beilstein J. Nanotechnol. 2020, 11, 180–212, doi:10.3762/bjnano.11.15

Simple synthesis of nanosheets of rGO and nitrogenated rGO

• Pallellappa Chithaiah,
• Madhan Mohan Raju,
• Giridhar U. Kulkarni and
• C. N. R. Rao

Beilstein J. Nanotechnol. 2020, 11, 68–75, doi:10.3762/bjnano.11.7

• ° does not appear indicating that the precursors were directly converted into rGO and N-rGO nanosheets. Figure 2 shows the Raman spectra of the rGO and N-rGO nanosheets. The Raman spectrum of the rGO sample (Figure 2a) shows D, G and 2D band at, respectively, 1362, 1594 and 2880 cm−1. The spectrum of the

• -hybridized carbon atoms in the rGO domains. The 2D-band is the second order of the D-band. The Raman results are consistent with previous reports [5]. Thermogravimetric analysis (TGA) was carried out to investigate the thermal stability of the rGO and N-rGO nanosheets. The study was performed in an oxygen

• and 600 °C as well. The corresponding XRD patterns, Raman spectra and SEM images are given in Figure S1 and Figure S2, respectively, in Supporting Information File 1. In order to understand the supercapacitor behavior of rGO and H-rGO (hydrogen-treated rGO) samples, we have carried out cyclic

Synthesis of amorphous and graphitized porous nitrogen-doped carbon spheres as oxygen reduction reaction catalysts

• Maximilian Wassner,
• Markus Eckardt,
• Andreas Reyer,
• Thomas Diemant,
• Michael S. Elsaesser,
• R. Jürgen Behm and
• Nicola Hüsing

Beilstein J. Nanotechnol. 2020, 11, 1–15, doi:10.3762/bjnano.11.1

• ) and (101) crystal planes of the graphite lattice. All Raman spectra (Figure 6 and Table 3) of the N-doped carbon spheres show two bands at ca. 1350 cm−1 (D band) and ca. 1600 cm−1 (G band). The G band is due to the E2g in-plane vibration mode of the graphite lattice and hence assigned to the sp2

• nitriding temperature, the microporosity increases strongly (Figure 9) and additionally we found a slight increase of the amount of graphenic structures in the catalysts, as indicated by the peak narrowing in the XRD patterns and the decreasing AD/AG ratio in the Raman signals. These structural changes may

• method of Brunauer, Emmett, and Teller in a relative pressure range of p/p0 0.01 to 0.3. The ratio of micropore surface area to external surface area was calculated by the t-plot method (thickness curve: carbon black STSA, fitted thickness range: 0.4–0.6 nm). Raman spectroscopy measurements were

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

• solution on the Raman intensities of the SERS substrate with hierarchical structures are experimentally studied. The intensity and distribution of the electric field of single and multiple Ag nanoparticles on the surface of a plane and with multiple micro/nanostructures are studied with COMSOL software

• 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