Mapping the local dielectric constant of a biological nanostructured system

• Wescley Walison Valeriano,
• Rodrigo Ribeiro Andrade,
• Juan Pablo Vasco,
• Angelo Malachias,
• Bernardo Ruegger Almeida Neves,
• Paulo Sergio Soares Guimarães and
• Wagner Nunes Rodrigues

Beilstein J. Nanotechnol. 2021, 12, 139–150, doi:10.3762/bjnano.12.11

• optical reflectance measurements and simulation, we were able to describe the origin of the strongly iridescent wing colors of this Amazonian rainforest damselfly. The method we demonstrate here should be useful for the study of other biological nanostructured systems. Keywords: dielectric constant

• different strategies found in nature, is astonishing [5][6]. Studies of the origin of physical colors in insects are numerous in the literature and the most commonly used tools are non-local optical reflectance, electron microscopy, and scanning probe microscopy techniques, which give support to theoretical

• [17][18][19]; nanostructures which make it a natural photonic crystal. We obtain quantitative information about the wing structure and its local relative permittivity values. We also simulate the optical reflectance using the extracted spatial profile of the relative permittivity and compare it with

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

• band gap in semiconductors. However, this approach has major problems. It is semi-empiric and indirect via the Tauc formula [12]. Therefore, it contains highly erroneous data. Here, the approach is to measure the reflectance data and accordingly plot the Tauc formula as a function of the energy

• . Typical plots of the Tauc formula from UV–vis reflectance spectra are given in Figure 1c. The intersection point at the energy axis gives the value of Eg. However, the determination of the intersection point is not very accurate. According to Figure 1c, defective nanoscale ZnO has a higher value of Eg

• ionized oxygen vacancies located either in volume or at the surface of the material. (b) PL spectra showing all possible defect centers, including non-paramagnetic ones. The defects emit visible light yielding a broad emission band [4]. (c) Tauc plot obtained from UV–vis reflectance measurements

Unravelling the interfacial interaction in mesoporous SiO₂@nickel phyllosilicate/TiO₂ core–shell nanostructures for photocatalytic activity

• Bridget K. Mutuma,
• Xiluva Mathebula,
• Isaac Nongwe,
• Bonakele P. Mtolo,
• Boitumelo J. Matsoso,
• Rudolph Erasmus,
• Zikhona Tetana and
• Neil J. Coville

Beilstein J. Nanotechnol. 2020, 11, 1834–1846, doi:10.3762/bjnano.11.165

• . Therefore, in this study we report on the growth of mesoporous SiO2@NiPS and titania-coated mSiO2@NiPS (mSiO2@NiPS/TiO2) core–shell nanostructures using a simple deposition-precipitation method. Transmission electron microscopy (TEM), N2 physisorption analysis, diffuse reflectance UV–visible spectroscopy

• functionality of nanomaterials greatly influence their photoactivity. UV–vis diffuse reflectance spectroscopy is a useful technique for probing the optoelectronic properties, band structure and molecular energy levels of semiconductors. It gives relevant information on the optical activity of nanomaterials as

• it involves the excitation of photogenerated electrons and holes. The bandgap energy values of nanomaterials can be estimated by direct extrapolation of either the F(R) spectrum or from the maximum absorption wavelength [47][50]. The solid-state UV–visible reflectance spectra of mSiO2@NiPS and mSiO2

Nanocasting synthesis of BiFeO₃ nanoparticles with enhanced visible-light photocatalytic activity

• Thomas Cadenbach,
• Maria J. Benitez,
• A. Lucia Morales,
• Cesar Costa Vera,
• Luis Lascano,
• Francisco Quiroz,
• Alexis Debut and
• Karla Vizuete

Beilstein J. Nanotechnol. 2020, 11, 1822–1833, doi:10.3762/bjnano.11.164

• -fabricated metal carboxylates as metal precursors. To the best of our knowledge, the synthesized particles are the smallest BiFeO3 particles ever prepared by any method. The samples were characterized by X-ray powder diffraction, transmission electron microscopy and UV–vis diffuse reflectance spectroscopy

• analyze the BiFeO3 nanomaterial are powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and UV–visible reflectance spectroscopy. Furthermore, we investigated the photocatalytic efficiency of this nanomaterial under visible light in the degradation of rhodamine B (RhB) as a model

• non-agglomerated nanoparticles. We would like to point out that, to the best of our knowledge, the present pure-phase 5.5 nm BiFeO3 nanoparticles are the smallest nanoparticles of that material so far. In order to investigate the optical properties of the nanocast BiFeO3 powder, diffuse reflectance UV

Wafer-level integration of self-aligned high aspect ratio silicon 3D structures using the MACE method with Au, Pd, Pt, Cu, and Ir

• Mathias Franz,
• Romy Junghans,
• Paul Schmitt,
• Adriana Szeghalmi and
• Stefan E. Schulz

Beilstein J. Nanotechnol. 2020, 11, 1439–1449, doi:10.3762/bjnano.11.128

• metals (Au, Pt, Pd, Cu, and Ir) were investigated to derive a set of technologies as platform for specific applications. Especially, the shape of the 3D structures and the resulting reflectance have been investigated. The Si nanostructures fabricated using Au nanoparticles show a perfect light absorption

• with a reflectance below 0.3%. The demonstrated technology can be integrated into common fabrication processes for microelectromechanical systems. Keywords: black silicon; bottom-up; metal-assisted chemical etching (MACE); nanowires; wafer-level integration; Introduction Silicon nanostructures

• random structures are typically vertically aligned nanowires, also called nanorods. Silicon nanowire arrays can be designed to have a low reflectance of about 1% in a broad spectral range, depending on their geometry. These silicon structures exhibit efficient light trapping because photons are scattered

Structural and electronic properties of SnO₂ doped with non-metal elements

• Jianyuan Yu,
• Yingeng Wang,
• Yan Huang,
• Xiuwen Wang,
• Jing Guo,
• Jingkai Yang and
• Hongli Zhao

Beilstein J. Nanotechnol. 2020, 11, 1321–1328, doi:10.3762/bjnano.11.116

• reflectivity in the infrared region, and the reflectance of the crystals doped with N, C, S, and B decreased sequentially. Based on this theoretical calculations, F-doped SnO2 is found to be the best photoelectric material for preparing low-emissivity coatings. Keywords: density functional theory (DFT); doped

• -emissivity glass. The most important property of low-emissivity is the reflectivity in the infrared region. According to the reflectance spectrum of the material, a good adiabatic behavior of the material requires the plasma frequency to be close to the visible region. Plasma is a system in which the

• transparent. Otherwise, it is impossible for the light to pass through, showing metallic reflectivity. The reflectance spectra of SnO2 crystals doped with non-metal elements are shown in Figure 4. It shows that SnO2 doped with F had the highest reflectance, followed by doping with N, C, S, and B in this order

Role of redox-active axial ligands of metal porphyrins adsorbed at solid–liquid interfaces in a liquid-STM setup

• Thomas Habets,
• Sylvia Speller and
• Johannes A. A. W. Elemans

Beilstein J. Nanotechnol. 2020, 11, 1264–1271, doi:10.3762/bjnano.11.110

• ) substrate and an n-tetradecane solution of the compound [7]. From real-time topographic signature changes in the STM images (Figure 1c), combined with optical reflectance spectroscopy, it was concluded that Mn=O complexes were readily formed in the presence of O2 gas. This was a surprising result, since a

Hybridization vs decoupling: influence of an h-BN interlayer on the physical properties of a lander-type molecule on Ni(111)

• Maximilian Schaal,
• Takumi Aihara,
• Marco Gruenewald,
• Felix Otto,
• Jari Domke,
• Roman Forker,
• Hiroyuki Yoshida and
• Torsten Fritz

Beilstein J. Nanotechnol. 2020, 11, 1168–1177, doi:10.3762/bjnano.11.101

• atomically thin h-BN interlayer to investigate its possible decoupling effect. To this end, we use in situ differential reflectance spectroscopy as an established method to distinguish between hybridized and decoupled molecules. By inserting an h-BN interlayer we fabricate a buried interface and show that

• comprehensive study we utilized differential reflectance spectroscopy (DRS), low-energy electron diffraction (LEED), low-temperature scanning tunneling microscopy (LT-STM), as well as photoelectron spectroscopy (PES). Our results reveal that DBP on h-BN/Ni(111) is well decoupled from the metal substrate Ni(111

• ). Furthermore, it was possible to obtain large domains of highly ordered molecules by depositing at an elevated substrate temperature of 170 °C. Results and Discussion Optical spectroscopy Figure 1 shows the comparison of the differential reflectance (DR) spectra (definition see Experimental section) of DBP on

Excitonic and electronic transitions in Me–Sb₂Se₃ structures

• Nicolae N. Syrbu,
• Victor V. Zalamai,
• Ivan G. Stamov and
• Stepan I. Beril

Beilstein J. Nanotechnol. 2020, 11, 1045–1053, doi:10.3762/bjnano.11.89

• crystal layers were characterized by a high reflectance, which is characteristic of metallic aluminum mirrors. Some measurements were also carried out on the spectrometer DFS-32 coupled with a Specord M-40 and a Jasco V-670. The photoconductivity spectra were obtained on a single spectrometer (MDR-2) with

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

• TiO2 porosity. Optical properties Figure 4 reports the optical transmittance of the TiO2/Au samples. Our previous studies involving TiO2/Au systems have shown that the reflectance has low values of about 5% and can thus be considered negligible [28]. A general decrease of the optical transmittance was

A 3D-polyphenylalanine network inside porous alumina: Synthesis and characterization of an inorganic–organic composite membrane

• Jonathan Stott and
• Jörg J. Schneider

Beilstein J. Nanotechnol. 2020, 11, 938–951, doi:10.3762/bjnano.11.78

• ALOX surface and the crystal of the ATR module could not be achieved, therefore we employed diffuse reflectance infrared Fourier transform spectroscopy (DRIFT) to analyze surface-grafted polymers. Figure 7 shows the NIR spectra of the outer surface of the pPA-functionalized ALOX-membranes. All observed

A set of empirical equations describing the observed colours of metal–anodic aluminium oxide–Al nanostructures

• Cristina V. Manzano,
• Jakob J. Schwiedrzik,
• Gerhard Bürki,
• Laszlo Pethö,
• Johann Michler and
• Laetitia Philippe

Beilstein J. Nanotechnol. 2020, 11, 798–806, doi:10.3762/bjnano.11.64

• aluminium oxide films and a metal layer (8 nm Cr and 25, 17.5 and 10 nm of Au), respectively. AAO films of different thickness were anodized and the Yxy values (Y is the luminance value, and x and y are the chromaticity values) were obtained via reflectance measurements. An empirical model based on the

• (AAO) films; anodization; structural colours; reflectance; polar coordinates; plasmonic effects; Introduction Recently, the reproduction of the vivid colours found in nature has received increasing interest [1]. These colours appear when light interacts with periodic structures. With regard to this

• design of colours by choosing a specific thickness [14]. Also, there is a model based on optical measurements (ellipsometry integrating indirectly thickness, porosity) in combination with total reflectance measurements to access the colours, in terms of L*a*b* values, of AAO–Al nanostructures filled with

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

• means, such as optical reflectance and absorption, electron energy loss spectroscopy, X-ray absorption, emission, and inelastic scattering. Regarding luminescence studies, PL is the light emission, i.e., the electromagnetic radiation from matter after the absorption of photons. It is originated by

Effect of Ag loading position on the photocatalytic performance of TiO₂ nanocolumn arrays

• Jinghan Xu,
• Yanqi Liu and
• Yan Zhao

Beilstein J. Nanotechnol. 2020, 11, 717–728, doi:10.3762/bjnano.11.59

• the array was measured using a laser of 325 nm excitation wavelength and a grating spectrometer (Horiba, JY iHR550). The diffuse reflectance absorption spectrum of the array was measured using an ultraviolet–visible spectrophotometer (UV–vis, Shimadzu, UV-3600). Photocatalytic experiments. The

Nanoparticles based on the zwitterionic pillar[5]arene and Ag⁺: synthesis, self-assembly and cytotoxicity in the human lung cancer cell line A549

• Dmitriy N. Shurpik,
• Denis A. Sevastyanov,
• Pavel V. Zelenikhin,
• Pavel L. Padnya,
• Vladimir G. Evtugyn,
• Yuriy N. Osin and
• Ivan I. Stoikov

Beilstein J. Nanotechnol. 2020, 11, 421–431, doi:10.3762/bjnano.11.33

• solutions was 3–5%. The attenuated total internal reflectance IR spectra were recorded with a Spectrum 400 (Perkin Elmer) Fourier spectrometer. Elemental analysis was performed with a Perkin Elmer 2400 Series II instrument. Mass spectra (MALDI-TOF) were recorded on an Ultraflex III mass spectrometer in a 4

Synthesis and enhanced photocatalytic performance of 0D/2D CuO/tourmaline composite photocatalysts

• Changqiang Yu,
• Min Wen,
• Zhen Tong,
• Shuhua Li,
• Yanhong Yin,
• Xianbin Liu,
• Yesheng Li,
• Tongxiang Liang,
• Ziping Wu and
• Dionysios D. Dionysiou

Beilstein J. Nanotechnol. 2020, 11, 407–416, doi:10.3762/bjnano.11.31

• ) spectra. UV–visible diffuse reflectance spectra were measured using a Lambda 750S UV–vis spectrophotometer (Perkin-Elmer, USA) calibrated using barium sulfate. Photoluminescence (PL) spectra were measured with a F-4600 fluorescence spectrophotometer (Hitachi, Japan) with an excitation wavelength of 400 nm

• (15.219 nm, 0.049 cm3 g−1) were analyzed according to the Barrett–Joyner–Halenda (BJH) method (Figure 4b). The larger pore volume and BET specific surface area confirmed that the CuO/tourmaline composite with 0D/2D CuO structure possessed an increased number of active sites. UV–vis diffuse reflectance

• ) BJH pore size distribution of the CuO, tourmaline, and CuO/tourmaline composite. (a) UV–vis diffuse reflectance spectra, (b) plots of (Ahν)2 vs hν, (c) transient photocurrent, and (d) time-resolved PL spectra of the CuO and CuO/tourmaline composite. (a) MB degradation, (b) the apparent pseudo-first

Facile biogenic fabrication of hydroxyapatite nanorods using cuttlefish bone and their bactericidal and biocompatibility study

• Satheeshkumar Balu,
• Manisha Vidyavathy Sundaradoss,
• Swetha Andra and
• Jaison Jeevanandam

Beilstein J. Nanotechnol. 2020, 11, 285–295, doi:10.3762/bjnano.11.21

• attenuated total reflectance (ATR) mode. Transmission electron microscopy and energy dispersive X-ray analysis (EDX) TEM micrographs of CB Hap NRs were obtained using TEM (model JEOL, Japan) at an operation voltage of 200 kV. A sufficient quantity of CB-Hap NR powder was placed on the carbon-coated copper

Gold and silver dichroic nanocomposite in the quest for 3D printing the Lycurgus cup

• Lars Kool,
• Floris Dekker,
• Anton Bunschoten,
• Glen J. Smales,
• Brian R. Pauw,
• Aldrik H. Velders and
• Vittorio Saggiomo

Beilstein J. Nanotechnol. 2020, 11, 16–23, doi:10.3762/bjnano.11.2

• study the reflected and transmitted colours we measured the 3D printed material using a reflectance spectrophotometer with the two different light sources (Figure 2). From the spectra of the two light sources, it is clear that the CRI 95 LED covers a larger part of the visible spectrum compared to the

• flashlight LED. The reflectance spectra of the 3D printed AgNP@PVA reflect this discrepancy in the illumination system, showing a greener colour when illuminated by the flashlight LED and a red-shifted spectrum when illuminated by the CRI 95 LED. The transmission spectra are more similar for the two

• Lycurgus cup might be possible by studying the reflectance and transmittance spectra from the Lycurgus cup and matching them with freshly synthesised Au and Ag nanoparticles in PVA. However, such spectra are missing in literature and the only few present are hand-drawn [13], making it impossible to

Multiple Fano resonances with flexible tunablity based on symmetry-breaking resonators

• Xiao bin Ren,
• Kun Ren,
• Ying Zhang,
• Cheng guo Ming and
• Qun Han

Beilstein J. Nanotechnol. 2019, 10, 2459–2467, doi:10.3762/bjnano.10.236

• reflectance). In addition to PhC waveguides, metal–dielectric–metal (MDM) waveguides are very attractive for researchers because they can support surface plasmon polaritons (SPPs) and allow for the control of light at the subwavelength scale. MDM waveguides provide an effective approach to chip-scale photonic

Targeted therapeutic effect against the breast cancer cell line MCF-7 with a CuFe₂O₄/silica/cisplatin nanocomposite formulation

• B. Rabindran Jermy,
• Vijaya Ravinayagam,
• Widyan A. Alamoudi,
• Dana Almohazey,
• Hatim Dafalla,
• Lina Hussain Allehaibi,
• Abdulhadi Baykal,
• Muhammet S. Toprak and
• Thirunavukkarasu Somanathan

Beilstein J. Nanotechnol. 2019, 10, 2217–2228, doi:10.3762/bjnano.10.214

• saline solution. The presence of cubic spinel CuFe2O4 on HYPS was confirmed through powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR) and diffuse reflectance UV–vis spectroscopy (DR UV–vis) analysis. The HYPS particles showed a surface area of 170 m2/g, pore size of 8.3 nm

• multifunctional biomedical applications. The crystalline phase, morphology, magnetization, and coordination environment of various spinel species were characterized using X-ray diffraction (XRD), BET surface area measurements, vibrating sample magnetometry (VSM), diffuse reflectance UV–vis spectroscopy (DR UV–vis

• /HYPS, the sample was analyzed using diffuse reflectance spectroscopy. Ferrite is a cubic spinel consisting of tetrahedral and octahedral crystalline sites [19]. Before cisplatin functionalization, a wide and strong absorption was observed between 200 and 700 nm that is characteristic of the spinel

Improved adsorption and degradation performance by S-doping of (001)-TiO₂

• Xiao-Yu Sun,
• Xian Zhang,
• Xiao Sun,
• Ni-Xian Qian,
• Min Wang and
• Yong-Qing Ma

Beilstein J. Nanotechnol. 2019, 10, 2116–2127, doi:10.3762/bjnano.10.206

• -ray diffractometer (XRD, Rigaku Industrial Corporation, Osaka, Japan) with Cu Kα radiation (λ = 1.5406 Å, operated at 40 kV and 100 mA). Transmission electron microscopy (TEM; JEM-2100, JEOL, Tokyo, Japan) was used to characterize the morphology of the samples. Ultraviolet–visible diffuse reflectance

Synthesis of highly active ETS-10-based titanosilicate for heterogeneously catalyzed transesterification of triglycerides

• Muhammad A. Zaheer,
• David Poppitz,
• Khavar Feyzullayeva,
• Marianne Wenzel,
• Jörg Matysik,
• Radomir Ljupkovic,
• Aleksandra Zarubica,
• Alexander A. Karavaev,
• Andreas Pöppl,
• Roger Gläser and
• Muslim Dvoyashkin

Beilstein J. Nanotechnol. 2019, 10, 2039–2061, doi:10.3762/bjnano.10.200

• this temperature range for P-ETS-10/60 might be due to the partial removal of the cations (decrease of the Na wt % from 9 to 7 after treatment with H2O2, see Table 2 (last column)) and of the H-bridged surface hydroxyl groups, as is also evident from the diffuse reflectance infrared Fourier transform

Toxicity and safety study of silver and gold nanoparticles functionalized with cysteine and glutathione

• Barbara Pem,
• Igor M. Pongrac,
• Lea Ulm,
• Ivan Pavičić,
• Valerije Vrček,
• Darija Domazet Jurašin,
• Marija Ljubojević,
• Adela Krivohlavek and
• Ivana Vinković Vrček

Beilstein J. Nanotechnol. 2019, 10, 1802–1817, doi:10.3762/bjnano.10.175

• with phalloidin to stain actin and visualize cell cytoskeleton (green), nucleic acid staining using Hoechst 33258 fluorescent dye (blue) and CLSM reflectance signals (red). The overlay of fluorescence stains and segmented reflectance signals are given in (g,h). The control cells show no high intensity

• reflective spots (g), while NP reflectance signals are visible as bright red signals and indicated by white arrows (c,d). The effect of silver (AgNPs) and gold nanoparticles (AuNPs) stabilized with cysteine (CYS) or glutathione (GSH), Ag+ and Au3+ ions on (a) total DNA damage and (b) DNA double-stranded

Growth dynamics and light scattering of gold nanoparticles in situ synthesized at high concentration in thin polymer films

• Corentin Guyot,
• Philippe Vandestrick,
• Ingrid Marenne,
• Olivier Deparis and
• Michel Voué

Beilstein J. Nanotechnol. 2019, 10, 1768–1777, doi:10.3762/bjnano.10.172

• plot. The incidence and scattered angles correspond to the values reported on the horizontal segment along the radius of the circle. The scattered azimuth angles correspond to the values reported along the outer circle. BRDF measurements show that the sample reflectance is neither isotropic nor

Remarkable electronic and optical anisotropy of layered 1T’-WTe₂ 2D materials

• Qiankun Zhang,
• Rongjie Zhang,
• Jiancui Chen,
• Wanfu Shen,
• Chunhua An,
• Xiaodong Hu,
• Mingli Dong,
• Jing Liu and
• Lianqing Zhu

Beilstein J. Nanotechnol. 2019, 10, 1745–1753, doi:10.3762/bjnano.10.170

• to understanding its structural and optical properties has been undertaken. Here we report quantitative, comprehensive work on the highly anisotropic, optical, electrical and optoelectronic properties of few-layer 1T’-WTe2 by azimuth-dependent reflectance difference microscopy, DC conductance

• and azimuth-dependent reflectance difference microscopy (ADRDM), we firstly identified the 1T’-phase WTe2 to have an optical anisotropic crystal structure. Secondly, a 12-electrode-structure was designed for the evaluation the electrical anisotropy of 1T’-WTe2, and the results demonstrated up to 103

• those reported from exfoliated thin nanosheet samples previously reported [29][30]. Additionally, a similar negative-direction shift of the peak positions is witnessed as the sample thickness increases [29]. Anisotropic crystal structure identification by azimuth-dependent reflectance difference