Effect of different silica coatings on the toxicity of upconversion nanoparticles on RAW 264.7 macrophage cells

• Cynthia Kembuan,
• Helena Oliveira and
• Christina Graf

Beilstein J. Nanotechnol. 2021, 12, 35–48, doi:10.3762/bjnano.12.3

• thicker shells. As a reference system, pure silica nanoparticles with a size of 50 nm were also coupled with RBITC and functionalized with AHAPS (sample SiO2 @RBITC_NH2). STEM images of each sample are shown in Supporting Information File 1, Figure S3. The STEM data of all the particles is summarized in

• -average values of the samples after redispersion in DMEM were lower than in water, except for the samples UC@thin_NH2, UC@thick_RBITC_NH2, and SiO2@RBITC_NH2. The lower Z-average values of these samples may indicate an increased stabilization by a protein corona [52][53][54][55][56]. However, the high

• aggregation of silica nanoparticles that occurred after redispersion in buffered solution and in physiological medium [54]. They reported that various proteins in a medium containing FBS were adsorbed onto the surface of bare SiO2 and amine-functionalized SiO2 nanoparticles, forming a protein corona with a

Atomic layer deposited films of Al₂O₃ on fluorine-doped tin oxide electrodes: stability and barrier properties

• Hana Krýsová,
• Michael Neumann-Spallart,
• Hana Tarábková,
• Pavel Janda,
• Ladislav Kavan and
• Josef Krýsa

Beilstein J. Nanotechnol. 2021, 12, 24–34, doi:10.3762/bjnano.12.2

• [2][3][4]. Depending on the thickness of the protecting layer, the passage of electrical current was progressively hindered as the layer thickness was increased, such that tunnelling became impossible [5]. A similar protection by ALD-grown layers of Ta2O5 [6] or SiO2 [7] was used for other

• alumina coatings was ascribed to its capability of passivating semiconductor/electrolyte interfaces, thus reducing photogenerated charge-carrier recombination (e.g., on BiVO4 [16]). In this work, Al2O3 films were deposited via ALD on thermally grown SiO2 on silicon or on fluorine-doped tin oxide (FTO

• the substrates before and after ALD deposition of an Al2O3 layer. As shown in Figure S1 and Figure S2 (Supporting Information File 1), the surface morphology of both substrates, the as-received and the Al2O3-coated SiO2 layer, was almost identical. This indicates a uniform distribution of the

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

• @NiPS/TiO2) core–shell nanostructures. The TEM results showed that the mSiO2@NiPS composite has a core–shell nanostructure with a unique flake-like shell morphology. XPS analysis revealed the successful formation of 1:1 nickel phyllosilicate on the SiO2 surface. The addition of TiO2 to the mSiO2@NiPS

• yielded the mSiO2@NiPS/TiO2 composite. The bandgap energy of mSiO2@NiPS and of mSiO2@NiPS/TiO2 were estimated to be 2.05 and 2.68 eV, respectively, indicating the role of titania in tuning the optoelectronic properties of the SiO2@nickel phyllosilicate. As a proof of concept, the core–shell nanostructures

• metal oxides, such as ZrO2 [16] and SiO2 [17], influence the morphology and surface features of the resulting binary metal oxide semiconductors. Moreover, these binary metal oxide semiconductors act as charge-transfer catalysts and significantly reduce the electron–hole recombination [18][19]. Another

Imaging and milling resolution of light ion beams from helium ion microscopy and FIBs driven by liquid metal alloy ion sources

• Nico Klingner,
• Gregor Hlawacek,
• Paul Mazarov,
• Wolfgang Pilz,
• Fabian Meyer and
• Lothar Bischoff

Beilstein J. Nanotechnol. 2020, 11, 1742–1749, doi:10.3762/bjnano.11.156

• ], the fabrication of graphene nanomeshes [8], the formation of single Si nanocrystals embedded in SiO2 for single-electron transistors [9], the spatially resolved engineering of the thermal conductivity in individual Si nanowires [10], as well as the creation of nano-Josephson superconducting tunnel

Seebeck coefficient of silicon nanowire forests doped by thermal diffusion

• Shaimaa Elyamny,
• Elisabetta Dimaggio and
• Giovanni Pennelli

Beilstein J. Nanotechnol. 2020, 11, 1707–1713, doi:10.3762/bjnano.11.153

• layer of oxide as a result of the HNO3 etching. The doping of the silicon nanowires has been carried out by thermal diffusion from a solid source. At first, the chips with the SiNW forests, with a surface of roughly 1 × 1 cm2 have been cleaned in buffered HF (BHF) for 1 min, to remove the SiO2 grown

• penetration of the doping species (phosphorous, in our case) into the silicon. It requires an oxidizing environment, at least in a first preliminary phase, to grow a thin SiO2 layer at the surface as a barrier for the doping species, forcing the diffusion into silicon. In the specific case of thermoelectric

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

• best of our knowledge, there have been no studies on the FL of monolayers of molecules on metal-supported hBN layers, yet. Kerfoot et al. [22] studied the FL of PTCDA and perylene-3,4,9,10-tetracarboxylic-3,4,9,10-diimide (PTCDI) on an exfoliated hBN monolayer that was transferred onto SiO2. Forker et

• , causing an enhancement by a factor of not more than 102–103 [46]. Recently, hBN has gained interest as a SERS substrate [49]. In a comparative study on 2DMs on SiO2 it was shown that hBN had an enhancement effect on the Raman modes of adsorbed copper phthalocyanine molecules [50]. The effect was explained

• observed for hBN on SiO2/Si [61], on Cu foils [62], and on other metal foils [63][64] for our samples of hBN/Cu(111). This is an obvious discrepancy, which we cannot explain based on our current data. It may, however, be related to the specific interface between hBN and the single crystalline Cu substrate

Amorphized length and variability in phase-change memory line cells

• Nafisa Noor,
• Sadid Muneer,
• Raihan Sayeed Khan,
• Anna Gorbenko and
• Helena Silva

Beilstein J. Nanotechnol. 2020, 11, 1644–1654, doi:10.3762/bjnano.11.147

• -switching process and not to the permanent and detrimental electrical breakdown failure that occurs in any dielectric material. Experimental The patterned GST-225 line cells used for this study were deposited on silicon dioxide (SiO2), had bottom metal contact pads (tungsten with Ti/TiN liner), and were

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

• , a SiO2 thin film was grown on the silicon substrate before Ag2S deposition through rapid thermal oxidation (RTO) at a temperature of 950 °C for 25 s, and then HF etchant was used to open a Si window on SiO2. The experimental details regarding the RTO process are presented elsewhere [20]. To

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

• will be oxidised to the intermediate state SiO2, which is etched by HF. In this case no H2 is formed. Due to the high number of involved holes, this etching mechanism is strongly correlated to the interface of silicon and the noble metal. This regime will lead to a straight silicon etching profile

Impact of fluorination on interface energetics and growth of pentacene on Ag(111)

• Qi Wang,
• Meng-Ting Chen,
• Antoni Franco-Cañellas,
• Bin Shen,
• Thomas Geiger,
• Holger F. Bettinger,
• Frank Schreiber,
• Ingo Salzmann,
• Alexander Gerlach and
• Steffen Duhm

Beilstein J. Nanotechnol. 2020, 11, 1361–1370, doi:10.3762/bjnano.11.120

• [40][41][42][43][44]. However, in thin films comprised of molecules in a standing orientation on SiO2 (long molecular axis perpendicular to the substrate), the IE of PEN decreases to 4.90 eV and the IE of PFP increases to 6.65 eV [45]. The opposite trend of the orientation dependency of the IEs has

Effect of localized helium ion irradiation on the performance of synthetic monolayer MoS₂ field-effect transistors

• Jakub Jadwiszczak,
• Pierce Maguire,
• Conor P. Cullen,
• Georg S. Duesberg and
• Hongzhou Zhang

Beilstein J. Nanotechnol. 2020, 11, 1329–1335, doi:10.3762/bjnano.11.117

• synthesized using a CVD microreactor method, described in detail in [33], directly on 285 nm SiO2/Si substrates, which also served as the back-gate in the FET configuration. MoS2 flakes were contacted with electrodes using standard electron beam lithography on polymethyl methacrylate (PMMA) resist, followed

• helium ion microscope chamber (after initial electrical testing to confirm functionality) and were irradiated with the stage tilt angle set to 0°. At this angle of incidence, the helium ion beam ought to produce sulfur vacancies chiefly in the bottom sulfuric layer of the SiO2-supported MoS2 flake [34

• atomic vacancy yield per each delivered ion as a function of target penetration depth on the 35 nm-Au/5 nm-Ti/0.7 nm-MoS2/285 nm-SiO2 stack [41]. As evident from Figure 3d, the sulfur sputtering yield at the Ti–MoS2 interface is very close to that of unencapsulated MoS2 [15], indicating notable damage to

Ultrasensitive detection of cadmium ions using a microcantilever-based piezoresistive sensor for groundwater

• Dinesh Rotake,
• Anand Darji and
• Nitin Kale

Beilstein J. Nanotechnol. 2020, 11, 1242–1253, doi:10.3762/bjnano.11.108

• . [28], but it is not suitable for other high-temperature sputtering processes. Microcantilevers based on SiO2 have been manufactured by Tang et al. [29] to enhance the sensitivity of cantilever sensors. Many authors use optical setups for microcantilevers. However, an optical output has several

• . It was calibrated using atomic force microscopy (AFM) [40]. The process begins with thermal oxidation of Si at 1000 °C using an oxidation furnace to obtain a thermally grown SiO2 layer followed by masking and etching to get the desired pattern. The polysilicon is deposited in a low-pressure chemical

• vapor deposition (LPCVD) furnace at 630 °C and boron doping (1018 per cm3) is carried out using ion implantation at 35 keV. The upper SiO2 layer is formed by re-oxidizing the polysilicon in an oxidation furnace [40]. The stiffness (k) of the fabricated piezoresistive sensor measured using AFM is 131–146

3D superconducting hollow nanowires with tailored diameters grown by focused He⁺ beam direct writing

• Rosa Córdoba,
• Alfonso Ibarra,
• Dominique Mailly,
• Isabel Guillamón,
• Hermann Suderow and
• José María De Teresa

Beilstein J. Nanotechnol. 2020, 11, 1198–1206, doi:10.3762/bjnano.11.104

• transport study using the typical four-point-probe configuration has been performed. Following the procedure described in [17], first 3D NWs were placed flat on the SiO2 layer of a Si/SiO2 substrate by means of a nano-manipulator. Then, four Pt FIBID contacts were grown to connect the NWs to pre-patterned

• -patterned Ti pads (150 nm in thickness) to prevent charge effects on the insulator layer (250 nm thick of SiO2) thermally grown on a silicon wafer [23]. These chips were fabricated following a routine recipe for UV optical lithography using a lift-off method. For the electron tomography and (HR)STEM

Nonadiabatic superconductivity in a Li-intercalated hexagonal boron nitride bilayer

• Kamila A. Szewczyk,
• Izabela A. Domagalska,
• Artur P. Durajski and
• Radosław Szczęśniak

Beilstein J. Nanotechnol. 2020, 11, 1178–1189, doi:10.3762/bjnano.11.102

• ][17][18][19], Ru [20][21], Pt [22][23], SiC [24][25][26], and SiO2 [27][28][29]. Unfortunately, the obtained experimental data showed that the incompatible crystalline structure of the above materials leads to significant suppression of the carrier mobility of graphene [13][30]. It is now assumed that

• result is radically different from the data obtained for graphene/SiO2 [33]. In addition, hBN monolayers exhibit a high temperature stability, a low dielectric constant (ε = 3–4), and a high thermal conductivity [34]. The band gap of hBN is about 5.9 eV [35]. Furthermore, which is also important, hBN is

Scanning tunneling microscopy and spectroscopy of rubrene on clean and graphene-covered metal surfaces

• Karl Rothe,
• Alexander Mehler,
• Nicolas Néel and
• Jörg Kröger

Beilstein J. Nanotechnol. 2020, 11, 1157–1167, doi:10.3762/bjnano.11.100

• ] and hexagonal boron nitride (h-BN) [3] have been studied in detail. In contrast, vibrational spectroscopy at the single-molecule level is scarce. Scanning tunneling spectroscopy (STS) of vibronic levels of 1,3,5-tris(2,2-dicyanovinyl)benzene on graphene-covered h-BN on SiO2 [4], of cobalt

• phthalocyanine molecules on graphene-covered SiO2/Si samples [5] as well as on h-BN-covered Ir(111) [6], of conjugated oligohenylenes on h-BN-covered Cu(111) [7], of manganese phthalocyanine on h-BN-covered Rh(111) [8], and of 5,10,15,20-tetraphenylbisbenz[5,6]indendo[1,2,3-cd:1′,2′,3′-lm]perylene on graphene

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

• of a NaYF4:Mn/Yb/Er@photosensitizer doped with SiO2 This allowed for the integration of photodynamic and photothermic therapy to improve the treatment against multidrug-resistant bacteria [82]. It was demonstrated that such nanodevices exhibited superior antibacterial activity towards drug-resistant

Measurement of electrostatic tip–sample interactions by time-domain Kelvin probe force microscopy

• Christian Ritz,
• Tino Wagner and
• Andreas Stemmer

Beilstein J. Nanotechnol. 2020, 11, 911–921, doi:10.3762/bjnano.11.76

• exfoliation from bulk graphite [32][33] and deposited on a piece of Si/SiO2. Measurements were carried out using an Asylum Research Cypher AFM connected to a Zurich Instruments HF2 lock-in amplifier. Figure 3 shows the results of the open-loop controller. During the FM-AFM measurement the tip voltage was

• the electrostatic potential above the graphene flake and the SiO2 substrate. The patterns observable on the graphene flake are most likely caused by water droplets, which have formed due to the ambient conditions [34][35]. Small changes in the patterns were observed between two different scans

• surface potential above the graphene flake is smaller than that above the SiO2 substrate. The residual of the state observer is shown in Figure 3i. This signal contains the amount of the frequency shift that could not be attributed to any surface property, for example the estimated measurement noise. In

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

• central region of the microbath. This implies that the beams should be narrow and have a low divergence. To realize this, we chose the single-stripe waveguide of our TripleX waveguiding platform [9]. This is a rectangular Si3N4 ridge waveguide embedded in SiO2 cladding. The TripleX platform offers high

• have control structures. The first fabrication step is the wet thermal oxidation of Si at 1150 °C to obtain an 8 µm thick layer of SiO2 (Figure 5a). This layer serves as the bottom cladding for the excitation waveguides. Its thickness is chosen such that the 785 nm light within the excitation

• away from the edge. In the next step, a 3 µm thick layer of SiO2 is deposited using LPCVD (Figure 5e). This layer acts as an upper cladding of the excitation waveguides and separates these from the waveguiding layer that follows. For simplicity, we do not show the surface topography resulting after

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

• Technology, Kattankulathur 603 203, Tamil Nadu, India 10.3762/bjnano.11.66 Abstract The influence of single-layer graphene on top of a SiO2/Si surface on the orientation of nonplanar lead phthalocyanine (PbPc) molecules is studied using two-dimensional grazing incidence X-ray diffraction. The studies

• oriented pyrolytic graphite (HOPG) or SiO2, it has been reported that CuPc attains different orientations resulting in substantial differences in donor–acceptor energy level alignment at the interface. Thus, ordering and orientation of these molecules significantly affect charge carrier injection and

• ) substrate [24]. It will be interesting to explore the molecular orientation of nonplanar PbPc on single-layer graphene supported on a substrate. In this study, we have investigated the molecular orientation of a PbPc film deposited on chemical vapor deposition (CVD)-grown graphene transferred onto a SiO2/Si

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

• , ML and bulk samples, were mechanically exfoliated on top of SiO2/Si substrates (SiO2 thickness = 270 nm) using the scotch tape method [1][30][31]. The mechanical exfoliation process used in this study is similar to the one reported in our earlier work [30]. Prior to the exfoliation procedure, the

• WSe2 Mechanically exfoliated high-quality WSe2 nanomembranes were observed under an optical microscope through optical contrast differences on the SiO2/Si substrates. The optical image of monolayer (1L), ML, and bulk WSe2 is shown in Figure 1a. Monolayer TMDCs such as WSe2 have a ground state structure

• sapphire substrate is used compared to SiO2/Si substrates [24]. As the SiO2/Si susbstrate and the preparation method (mechanical exfoliation) remained the same for 1L and bulk WSe2 used in our study, this may be the reason why the intensity of the Raman mode remained unchanged even in bulk WSe2. Moreover

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

• plasma etching and subsequent annealing in Ar, yielding a considerable increase in the concentration of emitters in h-BN [122]; laser irradiation [123] even if the formation origin, in this case, is unclear; substrate strain-induced where a 20 nm-thick h-BN film grown via CVD is transferred into SiO2

A novel dry-blending method to reduce the coefficient of thermal expansion of polymer templates for OTFT electrodes

• Xiangdong Ye,
• Bo Tian,
• Yuxuan Guo,
• Fan Fan and
• Anjiang Cai

Beilstein J. Nanotechnol. 2020, 11, 671–677, doi:10.3762/bjnano.11.53

• thermal expansion (CTE) of the polymer template is much higher than the CTE of the dielectric layer. Here, a novel dry-blending method is described in which SiO2 nanoparticles are filled into a grooved silicon template, followed by permeation of polydimethylsiloxane (PDMS) into the SiO2 nanoparticle gaps

• . The SiO2 nanoparticles in the groove are extracted by curing and peeling off PDMS to prepare a PDMS/SiO2 composite template with a nanoparticle content of 83.8 wt %. The composite template has a CTE of 96 ppm/°C, which is a reduction by 69.23% compared with the original PDMS template. Finally, we

• achieved the alignment of OTFT electrodes using the composite template. Keywords: coefficient of thermal expansion; dry blending; organic thin-film transistors (OTFTs); OTFT electrodes; PDMS/SiO2 composite template; Introduction Organic thin-film transistors (OTFTs) provide a platform to construct next

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

Multilayer capsules made of weak polyelectrolytes: a review on the preparation, functionalization and applications in drug delivery

• Varsha Sharma and
• Anandhakumar Sundaramurthy

Beilstein J. Nanotechnol. 2020, 11, 508–532, doi:10.3762/bjnano.11.41

• template removal, which also affected the shell structure limiting their biological applications [25]. The use of silicon oxide (SiO2) templates is quite common, however, dissolution using hazardous hydrofluoric acid (HF) limits its application. It is mostly used with strong PE systems but has also been

• extended to weak PE assemblies [26]. The dissolution of a SiO2 core in a poly(allylamine hydrochloride) (PAH)/poly(methacrylic acid) (PMA) assembly with ammonium fluoride (NH4F) at a suitable pH contributed to both multilayer stability and colloidal stability as shown in the AFM images in Figure 2a–d [24

• phenol formaldehyde resin (MPR) multilayered hollow nanocapsules were obtained using SiO2 as a sacrificial template [47]. Notably, the excess charges induced into the multilayer films by the deprotonation of carboxylic acid groups at pH > 5 played a key role in destabilizing the hydrogen bonded films [48

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

• keep this error reasonably small. Also, the thin SiO2 layer has been neglected, because it is thinner that the computational grid and cannot be correctly modelled. We have performed complementary short simulations with a very limited sample size and with a 2 nm grid, which showed that errors coming

• from the SiO2 layer do not exceed 2%. A light source of 460 nm wavelength has been used, propagating along the y axis direction. Two independent simulations were performed, one with a transverse-electric (TE) polarized beam and the second one with a transverse-magnetic (TM) polarized beam. These

• ), they consist of Ag. Detailed EDS analysis of a cross section of a nanoisland is presented in Figure 8c. As can be seen, a thin layer of natural SiO2, about 2 nm thick, is present on the silicon surface. Interestingly, there is no oxide layer around the Ag nanostructures. The quality of the