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

• gold tip. We positioned a Glan–Taylor polarizer in the beam in front of the entrance slit of the spectrometer and collected spectra while rotating the polarizer. The Glan–Taylor prism only transmits the optical signal along its fast axis. Therefore, the angle-resolved polarization of the emitted signal

• approaching the gold tip to the SiNW, the angle-resolved polarization pattern changes from a circular pattern (Figure 4c) to a more structured shape in Figure 6d. It is likely that the high refractive index of the SiNW has a certain impact on the polarization of the photoluminescence emitted from the narrow

• gap between the gold tip and the SiNW. A more quantitative investigation of the polarization angle-resolved emission patterns in Figure 6 will be further pursued. The results shown in Figure 4 and Figure 6 demonstrate that it is possible to combine the polarization angle-resolved experiments with a

Straightforward synthesis of gold nanoparticles by adding water to an engineered small dendrimer

• Sébastien Gottis,
• Régis Laurent,
• Vincent Collière and
• Anne-Marie Caminade

Beilstein J. Nanotechnol. 2020, 11, 1110–1118, doi:10.3762/bjnano.11.95

• 7314, 33 rue St Leu, 80039 Amiens cedex 1, France 10.3762/bjnano.11.95 Abstract A small water-soluble phosphorus-containing dendrimer was engineered for the complexation of gold(I) and for its reduction under mild conditions. Gold nanoparticles were obtained as colloidal suspensions simply and only

• when the powdered form of this dendrimer was dissolved in water, as shown by transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX) analyses. The dendrimers acted simultaneously as mild reducers and as nanoreactors, favoring the self-assembly of gold atoms and promoting

• the growth and stabilization of isolated gold nanoparticles. Thus, an unprecedented method for the synthesis of colloidal suspensions of water-soluble gold nanoparticles was proposed in this work. Keywords: colloidal suspension; complexation; dendrimer; gold nanoparticle; phosphorus; Introduction

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

• of iron oxides in the form of magnetite (Fe3O4) or maghemite (Fe2O3) and are easy to produce through a few well-documented synthesis methods yielding different forms and structures (e.g., round, cubic, hexagonal, clusters, core–shell with gold, silica, polymers, or surfactants). A lot of research is

• the cell divides [111]. Another study compared the endocytosis of gold and iron oxide nanoparticles in a co-exposure experiment. The authors found that the cells are not selective and internalize nanoparticles of both types. However, they found that the co-exposure induces more endocytosis events than

Plant growth regulation by seed coating with films of alginate and auxin-intercalated layered double hydroxides

• Vander A. de Castro,
• Valber G. O. Duarte,
• Danúbia A. C. Nobre,
• Geraldo H. Silva,
• Vera R. L. Constantino,
• Frederico G. Pinto,
• Willian R. Macedo and
• Jairo Tronto

Beilstein J. Nanotechnol. 2020, 11, 1082–1091, doi:10.3762/bjnano.11.93

• samples was analyzed by SEM using a Carl Zeiss scanning microscope, model EVO 50. The sample was supported on the sample holder by dispersion of the powder on conductive double-sided adhesive tape. The samples were gold-coated before the measurements using a Sputter BAL-TEC, MED 0.50. Mass-coupled thermal

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

• Procédés et des Matériaux (LSPM), CNRS, Université Sorbonne Paris Nord, 93430, Villetaneuse, France CSPBAT, UMR 7244, Université Sorbonne Paris Nord, 93430 Villetaneuse, France 10.3762/bjnano.11.87 Abstract We propose the use of gold nanoparticles grown on the surface of nanoporous TiO2 films as surface

• -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

• , 0.1 M of NaCl and 5 mM of MgCl2, pH 7.5). The samples were left for 2 h in this solution before rinsing with Tris-HCl buffer solution and Milli-Q water. In order to prevent unspecific interactions between E2 and the gold surface, the sample was then left for 2 h in a solution of the blocking agent MCH

Gas-sensing features of nanostructured tellurium thin films

• Dumitru Tsiulyanu

Beilstein J. Nanotechnol. 2020, 11, 1010–1018, doi:10.3762/bjnano.11.85

• the high-vacuum deposition technique in order to grow Te nanotubes on silicon substrates containing previously deposited nanoparticles of silver or gold [22]. In both cases, 50 nm diameter Te nanotubes were obtained. When exposed to low concentrations of different toxic gases, including NO2, the Te

• performed using a DRONE–YM1 (Burevestnik, Russia) diffractometer with Fe Kα radiation. The rotational velocity of the scintillation counter was set to be either 2 or 4°/min. For the electrical and gas-sensing characterization, the samples were supplied with symmetrical gold or platinum electrodes

• , identified in our preliminary works as ohmics [25][26], which form electrically transparent contacts with Te. The gold or copper wires were then attached to the electrodes with a silver paste. Figure 1A shows the surface morphology of a Te film grown on a Pyrex glass substrate at a rate of 10 nm/s. As shown

Wet-spinning of magneto-responsive helical chitosan microfibers

• Dorothea Brüggemann,
• Johanna Michel,
• Naiana Suter,
• Matheus Grande de Aguiar and
• Michael Maas

Beilstein J. Nanotechnol. 2020, 11, 991–999, doi:10.3762/bjnano.11.83

• scanning electron microscope (SEM) using a Zeiss Supra 40 field-emission device (Carl Zeiss, Oberkochen, Germany) at an acceleration voltage of 3 kV. Prior to SEM analysis, dried fibers were sputter-coated with a 7 nm gold layer using a Bal-Tec SCD 005 sputter system (Leica Microsystems, Wetzlar, Germany

Key for crossing the BBB with nanoparticles: the rational design

• Sonia M. Lombardo,
• Marc Schneider,
• Akif E. Türeli and
• Nazende Günday Türeli

Beilstein J. Nanotechnol. 2020, 11, 866–883, doi:10.3762/bjnano.11.72

• factors needs to be taken into account when developing a carrier system for this purpose. Depending on the chosen pathway to cross the BBB, nanoparticle material, size and surface properties such as functionalization and charge should be tailored to fit the specific route of BBB crossing. Keywords: gold

• , nanoparticles are considered as solid colloidal particles with a size between 1 and 1000 nm [23]. They can be produced from a variety of different materials including polymers, lipids or inorganic materials such gold or iron oxide [21]. The first reported nanoparticles able to pass the BBB were poly(butyl

• (e.g., human serum albumin) [28], gold nanoparticles [29] and superparamagnetic iron oxide nanoparticles [30]. This review aims to summarize (i) the different pathways to cross the BBB, (ii) the strategies that can be employed to increase nanoparticle BBB permeation without disrupting the BBB, as well

Transition from freestanding SnO₂ nanowires to laterally aligned nanowires with a simulation-based experimental design

• Jasmin-Clara Bürger,
• Sebastian Gutsch and
• Margit Zacharias

Beilstein J. Nanotechnol. 2020, 11, 843–853, doi:10.3762/bjnano.11.69

• volumetric flow leads to a higher species dilution. Based on our numerical results, we were able to successfully grow laterally aligned SnO2 nanowires out of gold film edges and gold nanoparticles on a-plane sapphire substrates. In our experiments a horizontal 2-zone tube furnace was used. The generation of

• substrates were prepared by two different preparation methods for the catalyst seeds, which are required for the VLS process. As a catalyst material, gold was chosen. First, a-plane sapphire substrates with structured gold thin films (thickness 5 nm) by metal evaporation, and second, a-plane sapphire

• substrates covered with gold nanoparticles (Au NPs) were prepared. For the latter method, the substrates were cleaned with deionized (DI) water and dried with nitrogen before coating them with 10 µL of a 1:2 v/v% solution of Au NPs (80 nm gold nanospheres, citrate NanoXact 0.05 mg/mL, nanoComposix) and

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

• . The model proposed in this study was defined for two different metals, chromium and gold. The work reported in this manuscript provides a mathematical model to estimate the xy values in the CIE 1931 colour diagram by only measuring the thickness and porosity of the AAO films. Results and Discussion

• Alliance-Concept DP 650 DC magnetron sputtering equipment. 25, 17.5 and 10 nm thin films of gold were deposited on top of the AAO films using a Leica EM ACE600 sputtering equipment. The Au layers were deposited using a sputtering pressure and intensity of 5 × 10−2 mbar and 30 mA, respectively, and the Cr

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

Identification of physicochemical properties that modulate nanoparticle aggregation in blood

• Ludovica Soddu,
• Duong N. Trinh,
• Eimear Dunne,
• Dermot Kenny,
• Giorgia Bernardini,
• Ida Kokalari,
• Arianna Marucco,
• Marco P. Monopoli and
• Ivana Fenoglio

Beilstein J. Nanotechnol. 2020, 11, 550–567, doi:10.3762/bjnano.11.44

• at room temperature. In the case of SNPs, the samples were sputter-coated with a thick gold film (≈17 nm) under argon atmosphere to improve secondary electron emission during SEM imaging. The NPs morphology was observed at an acceleration voltage of 20 kV. Dynamic light scattering (DLS) The mean

Luminescent gold nanoclusters for bioimaging applications

• Nonappa

Beilstein J. Nanotechnol. 2020, 11, 533–546, doi:10.3762/bjnano.11.42

• , semiconductor quantum dots suffer from toxicity and are susceptible to oxidation. In this context, atomically precise gold nanoclusters protected by thiol monolayers have emerged as a new class of luminescent nanomaterials. Low toxicity, bioavailability, photostability as well as tunable size, composition, and

• optoelectronic properties make them suitable for bioimaging and biosensing applications. In this review, an overview of the sensing of pathogens, and of in vitro and in vivo bioimaging using luminescent gold nanoclusters along with the limitations with selected examples are discussed. Keywords: bioimaging

• ; biosensing; gold nanoclusters; immunoassay; luminescence; self-assembly; theranostics; Introduction Imaging methods play a central role in understanding the structural and functional biological processes of biomolecules, cells, tissues, organs, and even entire living organisms [1][2]. The importance 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

• within the PAH/DS capsule. The rupture and deformation of the capsules occurred via the formation of pores on the surface after laser irradiation at 530 nm (Figure 5c). The encapsulation of silver, gold and iron oxide NPs has been the most common in most of the studies [80][82][83][84]. The incorporation

• cell line showed a rapid uptake, demonstrating the potential for cancer therapy. Silica and gold NPs were assembled in a one pot assembly of specifically tailored diblock polymers of PLL and poly-ʟ-cysteine [82]. The electrostatic binding between the positively charged lysine blocks and negatively

• charged silica NPs as well as the disulfide linkages between cysteine blocks and gold NPs resulted in two types of functionalities in the capsule. In a similar way, the capsules incorporated with noble metal NPs (e.g., gold and silver) respond to external light illumination by increased surface plasmon

Preparation and in vivo evaluation of glyco-gold nanoparticles carrying synthetic mycobacterial hexaarabinofuranoside

• Gennady L. Burygin,
• Polina I. Abronina,
• Nikita M. Podvalnyy,
• Sergey A. Staroverov,
• Leonid O. Kononov and
• Lev A. Dykman

Beilstein J. Nanotechnol. 2020, 11, 480–493, doi:10.3762/bjnano.11.39

• serological identification of microorganisms and are also widely used as antigenic components of vaccines. The use of gold nanoparticles as carriers for glyco-epitopes is becoming an important alternative to the traditional conjugation with proteins and synthetic polymers. In this study, we aimed to prepare

• and evaluate in vivo glyco-gold nanoparticles (glyco-GNPs) bearing the terminal-branched hexaarabinofuranoside fragment (Ara6) of arabinan domains of lipoarabinomannan and arabinogalactan, which are principal polysaccharides of the cell wall of Mycobacterium tuberculosis, the causative agent of

• directly conjugated with spherical gold nanoparticles (d = 15 nm) to give two sets of glyco-GNPs, which were used for the immunization of rabbits. Dot assays revealed cross-reactions between the two obtained antisera with the hexaarabinofuranoside and the 2-aminoethyl aglycon used for the preparation of

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

• effective ripple growth was found for incidence angles in the range of 45–60° [11]. The angle and ion fluence dependencies of ripples formed on single crystal Si surfaces were studied by Lozano and co-workers [12]. The ripples on the Si surface are quite similar to those formed on gold substrates

• ., their wavelength increases (Figure 2e). Moreover, in the valleys fine drift lines parallel to the GCIB direction are observed, similar to those found on a gold surface [19]. The drift lines are parallel to the surface projection of the incidence ion-beam direction and perpendicular to the adjacent

• are formed (Figure 2f). These grooves represent the pits and scratches on the initial surface modified by the cluster beam bombardment. The shape of the grooves is similar to those formed on a gold surface irradiated by the GCIB at 70° [19]. The absence of visible ripple morphology in this case can be

Brome mosaic virus-like particles as siRNA nanocarriers for biomedical purposes

• Alfredo Nuñez-Rivera,
• Pierrick G. J. Fournier,
• Danna L. Arellano,
• Ana G. Rodriguez-Hernandez,
• Rafael Vazquez-Duhalt and
• Ruben D. Cadena-Nava

Beilstein J. Nanotechnol. 2020, 11, 372–382, doi:10.3762/bjnano.11.28

• RNA genome [22]. Also, the casid protein able to encapsidate anionic molecules, such as heterologous RNAs [23], enzymes [24], drugs [25], or gold nanoparticles [26] by charge complementarity with the possibility of directing them to target cells through the functionalization of the external surface of

• the capsid [25][27]. Similarly, VLPs from the closely related cowpea chlorotic mottle virus (CCMV) have been loaded with different cargos, including gold nanoparticles, negatively charged chromophores, and polymers [22]. Small interfering RNA (siRNA) is a promising therapeutic solution to address gene

• -siAkt1 showed the highest activity, inhibiting around 50% of tumor size when compared with the control (Figure 5B,C). The efficiency of BMV-VLPs in delivering siRNA is similar to that observed when nanoparticles of multilamellar gold niosomes were used to deliver siRNA-Akt [56]. The mice showed no

Poly(1-vinylimidazole) polyplexes as novel therapeutic gene carriers for lung cancer therapy

• Gayathri Kandasamy,
• Elena N. Danilovtseva,
• Vadim V. Annenkov and
• Uma Maheswari Krishnan

Beilstein J. Nanotechnol. 2020, 11, 354–369, doi:10.3762/bjnano.11.26

• . Characterization of the polyplex Electron microscopy: A small drop of the polyplex sample was placed on a conducting carbon tape and air-dried. The sample was then sputter-coated with a thin film of gold. The sample was placed in the sample chamber and imaged at an accelerating voltage of 3 kV using a cold field

Interactions at the cell membrane and pathways of internalization of nano-sized materials for nanomedicine

• Valentina Francia,
• Daphne Montizaan and
• Anna Salvati

Beilstein J. Nanotechnol. 2020, 11, 338–353, doi:10.3762/bjnano.11.25

• interactions is shape. Simulations indicated that based on the energy required for membrane bending, the uptake would be the highest for spheres followed by cubes, then rods, and lastly discs [144]. Nevertheless, a recent in vitro study using gold particles, showed that the number of internalized particles was

Using gold nanoparticles to detect single-nucleotide polymorphisms: toward liquid biopsy

• María Sanromán Iglesias and
• Marek Grzelczak

Beilstein J. Nanotechnol. 2020, 11, 263–284, doi:10.3762/bjnano.11.20

• and its implementation into point-of-care devices for common use. Covering the last twenty years, this review gives an overview of the state-of-the-art of the research on the use of gold nanoparticles in the development of colorimetric biosensors for the detection of single-nucleotide polymorphism as

• cancer biomarker. We discuss the main mechanisms of the assays that either are assisted by DNA-based molecular machines or by enzymatic reactions, summarize their performance and provide an outlook towards future developments. Keywords: amplification reactions; biomarkers; colorimetric biosensing; gold

• by discussing current technologies in clinics, we review the performance of recent sensors for single-point mutation in which gold nanoparticles act as signal transducers. We classify the discussed sensors according to whether the underlying mechanisms of detection involve enzymatic reactions or not

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

• exhibiting polycyclic structures such as porphyrins (Figure 2), inorganic particles such as gold, or so-called upconverting nanoparticles. Developed in its modern form by Dougherty in the 1970’s [17], PDT is currently clinically employed in dermatology (e.g., for actinic keratinosis), ophthalmology (e.g

Size effects of graphene nanoplatelets on the properties of high-density polyethylene nanocomposites: morphological, thermal, electrical, and mechanical characterization

• Tuba Evgin,
• Alpaslan Turgut,
• Georges Hamaoui,
• Zdenko Spitalsky,
• Nicolas Horny,
• Matej Micusik,
• Mihai Chirtoc,
• Mehmet Sarikanat and
• Maria Omastova

Beilstein J. Nanotechnol. 2020, 11, 167–179, doi:10.3762/bjnano.11.14

• , Philips). The nanocomposite microstructures were examined at a cryofractured surface in liquid nitrogen, and then coated with a thin layer of gold. XRD analyses (X’Pert PRO, Philips) were performed to determine the overall phase and crystalline structure of the samples. The XRD patterns were recorded at 5

• Alpha dielectric spectrometer supplied by Novocontrol Technologies GmbH. A BDS-1200 parallel-plate capacitor with two gold-plated electrodes was used as a test cell for the samples and provided by Novocontrol Technologies. The diameter and thickness of the samples was 20 mm and 0.5 mm, respectively. All

Nonclassical dynamic modeling of nano/microparticles during nanomanipulation processes

• Moharam Habibnejad Korayem,
• Ali Asghar Farid and
• Rouzbeh Nouhi Hefzabad

Beilstein J. Nanotechnol. 2020, 11, 147–166, doi:10.3762/bjnano.11.13

• the substrate, along with the dominant motion mode, the nonclassical theory of continuum mechanics and a developed von Mises yield criterion are employed to investigate the dynamical behavior of a cylindrical gold nanoparticle during manipulation. Timoshenko and Euler–Bernoulli beam theories based on

• the modified couple stress theory are used to model the dynamics of cylindrical gold nanoparticles while the finite element method is utilized to solve the governing equations of motion. The results show a difference of 90% between the classical and nonclassical models in predicting the maximum

• deflection before the beginning of the dominant mode and a difference of more than 25% in the dynamic modeling of a 200 nm manipulation of a gold nanoparticle with a length of 25 µm and aspect ratio of 30. This difference increases with each increment of the aspect ratio and reduction of manipulation

Molecular architectonics of DNA for functional nanoarchitectures

• Debasis Ghosh,
• Lakshmi P. Datta and
• Thimmaiah Govindaraju

Beilstein J. Nanotechnol. 2020, 11, 124–140, doi:10.3762/bjnano.11.11

• the dTn chain length and temperature [85]. The multichromophoric array of NDI and oligo-dTn assembled over a gold substrate showed photocurrent generation due to electron conduction because of the π‐stacked array of the NDI assembly. In their next design approach, two separate zinc binding systems, Zn

• of the advantages of this system was that the DNA–multichromophore organization could be aligned vertically over the gold electrode, which facilitated exothermic charge separation and suppressesed the ground-state charge transfer (CT) complexation between DPP and NDI, followed by the generation of a

• photocurrent (Figure 7b). However, the randomly assembled array of DPPNDI–dT40 immobilized across the gold electrode was unable to generate any photocurrent response owing to ground-state CT complexation of DPP with NDI in their random arrangement (Figure 7c). Tanaka, Ono, and co-workers reported the

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

• stability (Figure 9). We compared our result with other materials reported recently (Table 1). For conductivity measurements, the H-rGO sample was dispersed in ethanol and drop-cast on a gold gap electrode. The average resistance measured using a Keithley source meter is ca. 4 MΩ. The corresponding