Simultaneous electrochemical determination of uric acid and hypoxanthine at a TiO₂/graphene quantum dot-modified electrode

• Vu Ngoc Hoang,
• Dang Thi Ngoc Hoa,
• Nguyen Quang Man,
• Le Vu Truong Son,
• Le Van Thanh Son,
• Vo Thang Nguyen,
• Le Thi Hong Phong,
• Ly Hoang Diem,
• Kieu Chan Ly,
• Ho Sy Thang and
• Dinh Quang Khieu

Beilstein J. Nanotechnol. 2024, 15, 719–732, doi:10.3762/bjnano.15.60

• properties. Graphene quantum dots (GQDs) are zero-dimensional graphene derivatives consisting of one to few layers of graphene sheets with a size of less than 20 nm in width [11]. The missing bandgap results in an absence of luminescence in pristine graphene. However, a bandgap can be generated in GQDs

• of graphene. The broad nature of the diffraction peak is due to the structure of GQDs containing only few layers of graphene sheets [27]. The XRD pattern of TiO2/GQDs in solid form (dried at 100 °C for 3 h) exhibits characteristic peaks of anatase at 2θ = 25.6°, 38.1°, and 48.3°, corresponding to the

Laser synthesis of nanoparticles in organic solvents – products, reactions, and perspectives

• Theo Fromme,
• Sven Reichenberger,
• Katharine M. Tibbetts and
• Stephan Barcikowski

Beilstein J. Nanotechnol. 2024, 15, 638–663, doi:10.3762/bjnano.15.54

• produce graphite structures. The carbon shell is a surface modification and, as such, affects the nanoparticles’ catalyst properties either positively [37][155] or negatively [149]. A low number of graphene layers on the surface of the nanoparticles was found to enhance the catalytic activity during

Exfoliation of titanium nitride using a non-thermal plasma process

• Priscila Jussiane Zambiazi,
• Dolores Ribeiro Ricci Lazar,
• Larissa Otubo,
• Rodrigo Fernando Brambilla de Souza,
• Almir Oliveira Neto and
• Cecilia Chaves Guedes-Silva

Beilstein J. Nanotechnol. 2024, 15, 631–637, doi:10.3762/bjnano.15.53

• -dimensional (2D) materials with exceptional physical and chemical properties. These materials are typically exfoliated from three-dimensional (3D) layered crystals characterized by atomically thin layers held together by strong in-plane covalent bonds and weak out-of-plane van der Waals (vdW) forces. Apart

• materials by exfoliating massive materials. Hot electrons are shot into the crystal structure and cause repulsion between layers, resulting in few-layered 2D materials. Souza and coworkers [17] successfully demonstrated the production of few-layer hexagonal boron nitride nanosheets, starting from bulk boron

• peak positions, approximately 0.1° less positive, was observed in the X-ray diffractograms for the exfoliated material. This shift aligns with the indications of reduced crystallite size and is consistent with the outcomes reported by de Souza et al. [17], who obtained few layers of hexagonal BN using

Comparative analysis of the ultrastructure and adhesive secretion pathways of different smooth attachment pads of the stick insect Medauroidea extradentata (Phasmatodea)

• Julian Thomas,
• Stanislav N. Gorb and
• Thies H. Büscher

Beilstein J. Nanotechnol. 2024, 15, 612–630, doi:10.3762/bjnano.15.52

• delineate a potential pathway for adhesive secretions, originating from exocrine epidermal cells and traversing various layers before reaching the surface. Within the attachment pad, the fluid may influence the viscoelastic properties of the pad and control the attachment/detachment process. Understanding

• ). These evaginations are also visible in the µCT cross sections as radio-dense layers (Figure 2A). The exocrine cells exhibited a mixed red/blue signal in CLSM (Figure 2D) and appeared densely packed in the SEM sections (Figure 2C). The exocrine cells are likely surrounded by the hemolymph (he), which

• fluorescence signal in CLSM (Figure 2D). However, they were not visible in the µCT cross sections (Figure 2A). The arolium exhibits a sclerotized cuticle (cu) on its dorsal side. The sclerotized cuticle is composed of two layers, the inner layer showing light blue staining by toluidine blue (Figure 2B) and a

AFM-IR investigation of thin PECVD SiO_x films on a polypropylene substrate in the surface-sensitive mode

• Hendrik Müller,
• Hartmut Stadler,
• Teresa de los Arcos,
• Adrian Keller and
• Guido Grundmeier

Beilstein J. Nanotechnol. 2024, 15, 603–611, doi:10.3762/bjnano.15.51

• signal of the substrate material could be significantly reduced. Even layers that are so thin that they could hardly be measured in the contact mode can be analyzed with the surface-sensitive mode. Keywords: AFM-IR; polypropylene; surface-sensitive mode; silicon oxide; thin films; XPS; Introduction

• peaks of the two samples (shown in Table 1) additionally supports the result that the chemistry of both SiOx layers is the same. AFM-IR analysis The prepared samples were analyzed by photothermal AFM-IR. First, AFM images were collected in contact mode to visualize the sample surface (Figure 4). In the

Directed growth of quinacridone chains on the vicinal Ag(35 1 1) surface

• Niklas Humberg,
• Lukas Grönwoldt and
• Moritz Sokolowski

Beilstein J. Nanotechnol. 2024, 15, 556–568, doi:10.3762/bjnano.15.48

• set of distinct orientations, which are determined by the underlying substrates on all these surfaces. Furthermore, chains of QA have also been observed on insulating layers of KCl grown on Ag(100) or Cu(111) [19][26]. In this work, we report the growth of QA on the vicinal Ag(35 1 1) surface. The

On the additive artificial intelligence-based discovery of nanoparticle neurodegenerative disease drug delivery systems

• Shan He,
• Julen Segura Abarrategi,
• Harbil Bediaga,
• Sonia Arrasate and
• Humberto González-Díaz

Beilstein J. Nanotechnol. 2024, 15, 535–555, doi:10.3762/bjnano.15.47

• hidden layer with eleven neurons, and an output layer. The most notable difference is that the DLN involves two hidden layers, each one with ten neurons. Both MLP and DLN showed high Sp and Sn values of 85%–86% in the training and validation series. If we compare the linear IFPTML-ANN model with non

• , which involves two hidden layers, yielded similar result as IFPTML-MLP 7:7-11-1:1. Taking into account all the aforementioned results, we can consider both IFPTML-MLP and IFPTML-DLN as the best models with remarkably higher values of Sp and Sn of 85%–86% and AUROC values of 0.93–0.94. However, the DLN

Electron-induced deposition using Fe(CO)₄MA and Fe(CO)₅ – effect of MA ligand and process conditions

• Hannah Boeckers,
• Atul Chaudhary,
• Petra Martinović,
• Amy V. Walker,
• Lisa McElwee-White and
• Petra Swiderek

Beilstein J. Nanotechnol. 2024, 15, 500–516, doi:10.3762/bjnano.15.45

• surface held at 140 K with the precursor coverage amounting to a few molecular layers and irradiation performed at an electron energy of 500 eV [43]. The results revealed, in line with an earlier study [40], that the electron-driven decomposition of the precursor proceeds in two steps. First, electron

• ]. In the case of the thin layers deposited in the present experiment, the actual composition is, thus, also likely to vary from the first to the second deposition step. We recall, however, that in a situation near scenario A, AES probes the entire deposit. Therefore, again, trends between different

• volatile products during irradiation. We note that removal of the MA ligand may be particularly favorable in the present cryo-EBID experiments as compared to an actual cryo-FEBID process where the thickness of the condensed precursor layers is typically in the hundreds of nanometers regime [28][29]. MA

Photocatalytic degradation of methylene blue under visible light by cobalt ferrite nanoparticles/graphene quantum dots

• Vo Chau Ngoc Anh,
• Le Thi Thanh Nhi,
• Le Thi Kim Dung,
• Dang Thi Ngoc Hoa,
• Nguyen Truong Son,
• Nguyen Thi Thao Uyen,
• Nguyen Ngoc Uyen Thu,
• Le Van Thanh Son,
• Le Trung Hieu,
• Tran Ngoc Tuyen and
• Dinh Quang Khieu

Beilstein J. Nanotechnol. 2024, 15, 475–489, doi:10.3762/bjnano.15.43

• excellent heterojunctions between CoFe2O4 and GQDs. The former is favourable for more MB molecules to adsorb on the active sites of the photocatalysts, and the latter can facilitate the GQDs layers acting as electron acceptors, which are beneficial for suppressing the recombination of photogenerated

Fabrication of nanocrystal forms of ᴅ-cycloserine and their application for transdermal and enteric drug delivery systems

• Hsuan-Ang Tsai,
• Tsai-Miao Shih,
• Theodore Tsai,
• Jhe-Wei Hu,
• Yi-An Lai,
• Jui-Fu Hsiao and
• Guochuan Emil Tsai

Beilstein J. Nanotechnol. 2024, 15, 465–474, doi:10.3762/bjnano.15.42

• results were observed in Formulation Tests 2 and 3. The release of DCS for these two formulations was 0.24% and 0.36% after 24 h, respectively. Furthermore, in the Formulation Tests 2 and 3, two separate layers were observed from the residual solutions in the donor compartment. In summary, both the DCS

Superconducting spin valve effect in Co/Pb/Co heterostructures with insulating interlayers

• Andrey A. Kamashev,
• Nadir N. Garif’yanov,
• Aidar A. Validov,
• Vladislav Kataev,
• Alexander S. Osin,
• Yakov V. Fominov and
• Ilgiz A. Garifullin

Beilstein J. Nanotechnol. 2024, 15, 457–464, doi:10.3762/bjnano.15.41

• the two magnetic layers. Common knowledge suggests that this spin valve effect, which is due to the S/F proximity effect, is most pronounced in the case of perfect metallic contacts at the interfaces. Nevertheless, in our structures with intentionally deteriorated interfaces, we observed a significant

• full spin valve effect. A shift of the superconducting transition temperature Tc by switching the mutual orientation of the magnetizations of the two ferromagnetic Co layers from antiparallel to parallel amounted to ΔTc = 0.2 K at the optimal thickness of the superconducting Pb layer. Our findings

• superconducting spin valves. Keywords: ferromagnet; insulator layers; proximity effect; superconducting spin-valve; superconductor; Introduction Models and specific realizations of the superconducting spin valve (SSV) have been the subject of intensive research over the past 25 years [1][2][3][4][5][6][7][8][9

Sidewall angle tuning in focused electron beam-induced processing

• Sangeetha Hari,
• Willem F. van Dorp,
• Johannes J. L. Mulders,
• Piet H. F. Trompenaars,
• Pieter Kruit and
• Cornelis W. Hagen

Beilstein J. Nanotechnol. 2024, 15, 447–456, doi:10.3762/bjnano.15.40

• diffusion rate of adsorbed contamination is known to be enhanced by the presence of water layers [21]. But since the relevant quantities are hard to measure, the diffusion rate has not been included in the model, nor have some other factors such as scattering, porosity, and secondary etch product reactions

• of the chamber and other open surfaces. Additionally, on letting in water after deposition, the contamination level was found to be higher. This is consistent with reports of increased diffusion of hydrocarbons in the presence of adsorbed water layers. Therefore, to maintain clean working conditions

Modulated critical currents of spin-transfer torque-induced resistance changes in NiCu/Cu multilayered nanowires

• Mengqi Fu,
• Roman Hartmann,
• Julian Braun,
• Sergej Andreev,
• Torsten Pietsch and
• Elke Scheer

Beilstein J. Nanotechnol. 2024, 15, 360–366, doi:10.3762/bjnano.15.32

• aluminum oxide (AAO) template-assisted electrodeposition has attracted wide interest because of its low cost as well as high flexibility on tailoring the magnetic properties of magnetic systems and thus STT effects [8][9][10][11][12]. Moreover, it enables a larger number of free layers, whose magnetization

• can be flipped by STT [10] in one nanowire [9][11]. Comparing with the classical trilayer system (including one hard layer with fixed magnetization, one free layer, and one nonmagnetic spacer layer in between) [10], the presence of more free layers enhances, for example, the magnetoresistance (MR) [7

• ][13] and ferromagnetic resonance modes [14][15]. Meanwhile it has been shown that it might also lead to sequential flipping of different free layers, which, on the one hand, increases the complexity of the STT effects [16] and, on the other hand, expands its applications [5]. In this work, we present

Controllable physicochemical properties of WO_x thin films grown under glancing angle

• Rupam Mandal,
• Aparajita Mandal,
• Alapan Dutta,
• Rengasamy Sivakumar,
• Sanjeev Kumar Srivastava and
• Tapobrata Som

Beilstein J. Nanotechnol. 2024, 15, 350–359, doi:10.3762/bjnano.15.31

• stronger with the increasing number of interface gap states [52][53], this explains the comparatively higher values of RR in all annealed samples (Table 1). Thus, there exists a critical thickness (30 nm) of the NS-WOx layers in terms of effective elimination of Fermi level pinning at the interface and

• on the variation in work function with thickness for GLAD-grown WOx films in this study is valuable towards potential device applications, where work function optimization among consecutive layers is imperative. Moreover, the adopted rf sputtering technique in the present work ensures reduced surface

Determining by Raman spectroscopy the average thickness and N-layer-specific surface coverages of MoS₂ thin films with domains much smaller than the laser spot size

• Felipe Wasem Klein,
• Jean-Roch Huntzinger,
• Vincent Astié,
• Damien Voiry,
• Romain Parret,
• Houssine Makhlouf,
• Sandrine Juillaguet,
• Jean-Manuel Decams,
• Sylvie Contreras,
• Périne Landois,
• Ahmed-Azmi Zahab,
• Jean-Louis Sauvajol and
• Matthieu Paillet

Beilstein J. Nanotechnol. 2024, 15, 279–296, doi:10.3762/bjnano.15.26

• injection pulsed-pressure chemical vapor deposition (DLI-PP-CVD). Such samples are constituted of nanoflakes (with a lateral size of typically 50 nm, i.e., well below the laser spot size), with possibly a distribution of thicknesses and twist angles between stacked layers. As an essential preliminary, we

• SiO2 on Si substrates. Then, we discuss the applicability of the same criteria for significantly different DLI-PP-CVD MoS2 samples with average thicknesses ranging from sub-monolayer up to three layers. Finally, an original procedure based on the measurement of the intensity of the layer breathing

• modes is proposed to evaluate the surface coverage for each N (i.e., the ratio between the surface covered by exactly N layers and the total surface) in DLI-PP-CVD MoS2 samples. Keywords: molybdenum disulfide; number of layers; Raman spectroscopy; thin film; transition metal dichalcogenides

Design, fabrication, and characterization of kinetic-inductive force sensors for scanning probe applications

• August K. Roos,
• Ermes Scarano,
• Elisabet K. Arvidsson,
• Erik Holmgren and
• David B. Haviland

Beilstein J. Nanotechnol. 2024, 15, 242–255, doi:10.3762/bjnano.15.23

• with a mask consisting of a 190 nm thick layer of Cr and PMMA. After the release, we strip the PMMA and Cr layers, while taking care to not break the cantilevers. The difficulties associated with using KOH lead us to prefer the dry-etch described above in step (h). Tip deposition In scanning probe

• an electron-beam deposited platinum tip on the released Si-N cantilever of one chip. The tip has total height in the range of 1–2 μm. (b) An SEM image of the reverse cone structure, deposited using multiple layers of platinum. Note the larger connection to the Nb-Ti-N thin film to the left of the tip

Multiscale modelling of biomolecular corona formation on metallic surfaces

• Parinaz Mosaddeghi Amini,
• Ian Rouse,
• Julia Subbotina and
• Vladimir Lobaskin

Beilstein J. Nanotechnol. 2024, 15, 215–229, doi:10.3762/bjnano.15.21

• 0.15–0.18 nm and 0.42–0.48 nm away from the aluminum surface. These regions corresponded to the first and second water layers adjacent to the metal surface, respectively (as depicted in Supporting Information File 1, Figure S1). Further examination of the ion density profiles indicated the presence of

• vertical lines indicate the positions of water and ion layers. (a) Al(100), (b) Al(110), and (c) Al(111). Minimum energy of adsorption (kBT) for each SCA on three Al fcc slabs obtained through all-atom simulations: (a) Al(100), (b) Al(110), and (c) Al(111). Notably, Al(111) exhibits a stronger binding

Ion beam processing of DNA origami nanostructures

• Leo Sala,
• Agnes Zerolová,
• Violaine Vizcaino,
• Alain Mery,
• Alicja Domaracka,
• Hermann Rothard,
• Philippe Boduch,
• Dominik Pinkas and
• Jaroslav Kocišek

Beilstein J. Nanotechnol. 2024, 15, 207–214, doi:10.3762/bjnano.15.20

• with N2. We also performed several depositions on mica, but the material was found to be unsuitable for the irradiation studies at such high fluences because of significant macroscopic ion-induced damage through cracking and flaking of the upper layers after irradiation. Therefore, in the present study

Graphene removal by water-assisted focused electron-beam-induced etching – unveiling the dose and dwell time impact on the etch profile and topographical changes in SiO₂ substrates

• Aleksandra Szkudlarek,
• Jan M. Michalik,
• Inés Serrano-Esparza,
• Zdeněk Nováček,
• Veronika Novotná,
• Piotr Ozga,
• Czesław Kapusta and
• José María De Teresa

Beilstein J. Nanotechnol. 2024, 15, 190–198, doi:10.3762/bjnano.15.18

• extraordinary mechanical and electronic properties. Although many years have passed since its discovery, manipulating single graphene layers is still challenging using standard resist-based lithography techniques. Recently, it has been shown that it is possible to etch graphene directly in water-assisted

• formed, and they start to chemically react with graphene. There are a few possible reaction paths which could occur during this process: A first series of water FEBIE experiments have been performed on single, bi-, and triple layers of graphene in ESEM mode at a background pressure of 130 Pa, with a beam

• studies: A) optical microscopy, B) scanning electron microscopy (SEM), C) AFM, and D) correlative probe and electron microscopy (CPEM). The optical contrast of graphene placed onto SiO2/Si allows us to easily distinguish between its mono-, bi-, triple, and thicker flakes layers. The values (approx. 2.5 nm

Modification of graphene oxide and its effect on properties of natural rubber/graphene oxide nanocomposites

• Nghiem Thi Thuong,
• Le Dinh Quang,
• Vu Quoc Cuong,
• Cao Hong Ha,
• Nguyen Ba Lam and
• Seiichi Kawahara

Beilstein J. Nanotechnol. 2024, 15, 168–179, doi:10.3762/bjnano.15.16

• G' value of DPNR/GO could be explained by thin and large surface GO layers. The GO sheet could not withstand large shearing force, causing the rubber particles to slip. The high G' value of DPNR/GO-VTES(a) and DPNR/GO-VTES(b) may be due to hard silica particles, which may contribute to higher energy

CdSe/ZnS quantum dots as a booster in the active layer of distributed ternary organic photovoltaics

• Gabriela Lewińska,
• Piotr Jeleń,
• Zofia Kucia,
• Maciej Sitarz,
• Łukasz Walczak,
• Bartłomiej Szafraniak,
• Jerzy Sanetra and
• Konstanty W. Marszalek

Beilstein J. Nanotechnol. 2024, 15, 144–156, doi:10.3762/bjnano.15.14

• relations of refractive indices and extinction coefficient were investigated. The morphologies of the thin films were studied with atomic force microscopy. The chemical boundaries of the ternary layers were determined by Raman spectroscopy. Based on UPS studies, the energy diagram of the potential devices

• was determined. The resistivity of the layers was determined using impedance spectroscopy. Simulations (General-Purpose Photovoltaic Device Model) showed a performance improvement in the cells with quantum dots of 0.36–1.45% compared to those without quantum dots. Keywords: efficiency; luminescence

• -transporting layers [24], active absorbing layers, and other components [25][26]. Inorganic quantum dots are considered substitutes for fullerene acceptors. Their biggest advantages are a tunable band gap, various absorption spectra, and comparatively high mobility of carriers [27][28]. The application of

In situ optical sub-wavelength thickness control of porous anodic aluminum oxide

• Aleksandrs Dutovs,
• Raimonds Popļausks,
• Oskars Putāns,
• Vladislavs Perkanuks,
• Aušrinė Jurkevičiūtė,
• Tomas Tamulevičius,
• Uldis Malinovskis,
• Iryna Olyshevets,
• Donats Erts and
• Juris Prikulis

Beilstein J. Nanotechnol. 2024, 15, 126–133, doi:10.3762/bjnano.15.12

• . Automation software was designed to terminate the anodization process at preset PAAO thickness values. While the concept was illustrated using the widely used method of anodization in a 0.3 M oxalic acid electrolyte with a 40 V potential, it can be readily customized for other protocols. PAAO layers with

• achieve precise optical characterization, one could employ spectroscopic ellipsometry (SE) with more refined division into sub-layers [26] and consider additional material properties, such as the anisotropy of PAAO [27] and the optical dispersion of the refractive index (RI) of Al2O3 [28]. However, for

• attenuate the signal at short and long wavelengths. For very thin PAAO layers (hPAAO < 200 nm), the reflectance spectra did not have significant interferometric features (i.e., Fabry–Pérot-like fringes) in the usable wavelength range of the system. Furthermore, as will be discussed later, at the initial

Influence of conductive carbon and MnCo₂O₄ on morphological and electrical properties of hydrogels for electrochemical energy conversion

• Sylwia Pawłowska,
• Karolina Cysewska,
• Yasamin Ziai,
• Jakub Karczewski,
• Piotr Jasiński and
• Sebastian Molin

Beilstein J. Nanotechnol. 2024, 15, 57–70, doi:10.3762/bjnano.15.6

• structures were examined in terms of their morphology, electrical properties, and catalytic layers in the OER process. Results and Discussion Characterisation of hydrogel-based polymer composites with dispersed catalytic and conductive particles Scanning electron microscopy (SEM) analysis of hydrogel samples

• presented in this work indicate a promising direction for further work aimed at obtaining electrocatalytic layers participating in the OER process and characterized by high efficiency, while using a simple one-step method for synthesizing a conductive hydrogel containing electrochemically active particles

Nanotechnological approaches in the treatment of schistosomiasis: an overview

• Lucas Carvalho,
• Michelle Sarcinelli and
• Beatriz Patrício

Beilstein J. Nanotechnol. 2024, 15, 13–25, doi:10.3762/bjnano.15.2

• . It can have one or multiple layers. Due to that, their size can range from 30 nm to the micrometer range [37]. As drug vehicles, they exhibit unique properties, such as protection of encapsulated compounds from physiological degradation, extended drug half-life, controlled release of the drug

TEM sample preparation of lithographically patterned permalloy nanostructures on silicon nitride membranes

• Joshua Williams,
• Michael I. Faley,
• Joseph Vimal Vas,
• Peng-Han Lu and
• Rafal E. Dunin-Borkowski

Beilstein J. Nanotechnol. 2024, 15, 1–12, doi:10.3762/bjnano.15.1

• membrane also allows for high-resolution patterning since there is less electron scattering during exposure [26]. The purpose of applying two layers of resist is to create a large undercut by using a bottom layer that is more sensitive than the top layer. This prevents the unwanted deposition of metal that

• techniques, a one-time exposure is possible with the help of high accelerating voltage during electron beam exposure. In this process, rather than doing one resist deposition and exposure after another, the layer selectivity is controlled by the electron beam dose and the sensitivity of the two layers. Only

• in the copolymer (higher sensitivity) the chain scission reaction occurs at low doses; at higher doses, both layers were exposed. The exposure scheme is given in Figure 3. The doses were chosen by considering that the copolymer is 2–3 times more sensitive than PMMA [25]. If the exposure dose is too