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

• characterized in the 31P NMR spectra as a broad signal at 33.2 ppm (P=S–Au, Δδ = −17.4 ppm) and a doublet at 23.8 ppm (P=N, Δδ = +3 ppm) (Table 1). Modifications of the 31P NMR chemical shifts are frequently connected with modifications in the (crystallographic) cone angles. It has been shown, in particular

• chemical signal. In addition, it has been shown that the 2JPP coupling constant values decrease when the electron-withdrawing power of the substituents decreases [55]. The density functional theory (DFT) calculations on free and Au-complexed P=N–P=S linkages have shown that a charge is transferred from the

• shape similar to a spherical desert rose crystal also constituted by associated triangles. An enlargement of Figure 3C is given in Figure S1 (Supporting Information File 1), from which an Au–Au distance of ≈2.96 Å can be measured. This distance is shorter than what has been seen for the gold NPs and

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

Monolayers of MoS₂ on Ag(111) as decoupling layers for organic molecules: resolution of electronic and vibronic states of TCNQ

• Asieh Yousofnejad,
• Gaël Reecht,
• Nils Krane,
• Christian Lotze and
• Katharina J. Franke

Beilstein J. Nanotechnol. 2020, 11, 1062–1071, doi:10.3762/bjnano.11.91

• of decoupling layers made use of the in situ fabrication of single layers of transition metal dichalcogenides on metal surfaces. A monolayer of MoS2 on Au(111) provided very narrow molecular resonances, close to the thermal resolution limit at 4.6 K [26]. The exquisite decoupling efficiency has been

• nature of the substrate [33]. One may thus envision tuning the bandgap alignment for decoupling either the lowest unoccupied (LUMO) or the highest occupied molecular orbital (HOMO) of the molecules. While MoS2 on Au(111) has already been established as an outstanding decoupling layer [26], we will now

• explore this potential for MoS2 on a Ag(111) surface. In agreement with the band modifications of WS2 on Au(111) and Ag(111), we find that the bandgap remains almost the same, albeit shifted to lower energies [33]. As a test molecule we chose tetracyanoquinodimethane (TCNQ). Due to its electron-accepting

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

• . Specifically, we demonstrate that the TiO2 background pressure during pulsed laser deposition and the annealing conditions offer control over the formation of Au nanoparticles with different sizes, shapes and distributions, yielding a versatile sensor. We have exploited the surface for the detection of 17β

• -estradiol, an emerging contaminant in environmental waters. We have found a limit of detection of 1 nM with a sensitivity allowing for a dynamic range of five orders of magnitude (up to 100 µM). Keywords: aptamer; Au nanoparticles; 17-β estradiol (E2); plasmonics; sensor; surface-enhanced Raman scattering

• antireflection abilities [13][14][15]. These composite microstructures have also shown to maximize the path of the Raman excitation laser beam within the substrate, leading to signals with higher intensity. Samransuksamer et al. [16] used TiO2 nanorods decorated with Au NPs, deposited via precipitation by

Gas-sensing features of nanostructured tellurium thin films

• Dumitru Tsiulyanu

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

• with an approximate average size of 100 nm. Assuming the neutrality of the Au/Te contacts, the electrical conductivity of the film is mainly controlled by the bulk, surface and grain boundary resistances. On the other hand, due to the peculiarities of chalcogens and chalcogenide materials [1][30], a

Electrochemical nanostructuring of (111) oriented GaAs crystals: from porous structures to nanowires

• Elena I. Monaico,
• Eduard V. Monaico,
• Veaceslav V. Ursaki,
• Shashank Honnali,
• Vitalie Postolache,
• Karin Leistner,
• Kornelius Nielsch and
• Ion M. Tiginyanu

Beilstein J. Nanotechnol. 2020, 11, 966–975, doi:10.3762/bjnano.11.81

• metal deposition. Note that the nanowire was visible in the optical microscope due to its length of 70 µm, despite the small diameter. The distance between the contacts is 20 µm. A photograph of five contacted nanowires on a glass substrate after Cr/Au deposition and lift-off is presented in the inset

• light. The current–voltage characteristics measured with and without illumination reveal a good ohmic quality of the prepared Cr/Au contacts (Figure 8). Therefore, one can conclude that the detector works in the photoconductor mode. The responsivity of the detector is defined as where Iphoto is the

• followed by 250 nm Au layer was sputtered using a magnetron from Torr International Inc model No: CRC622-2G2-RF-DC and lift-off was performed with Microposit remover 1165 at 50 °C. Photoelectrical characterization. To excite photoconductivity in the GaAs nanowires, the radiation from a Xenon lamp DKSS-150

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

• 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

• control of the powder temperature, and by reducing the competing Au cluster density (i.e., using a well-separated Au cluster or an abrupt gold film edge). This gives the possibility to look deeper into the laterally aligned NW growth and to achieve higher control of the resulting NW properties. To use the

• down passively. This half step is also intuitively included in the standard procedure without pulsed gas inflow (Figure 8a). All NW lengths are compared for NWs grown out of Au NPs (Ø 80 nm) (Figure 8 and Figure 9). This allows the comparison of the NW lengths, which is otherwise additionally

Adsorption behavior of tin phthalocyanine onto the (110) face of rutile TiO₂

• Lukasz Bodek,
• Mads Engelund,
• Aleksandra Cebrat and
• Bartosz Such

Beilstein J. Nanotechnol. 2020, 11, 821–828, doi:10.3762/bjnano.11.67

• between Sn-up and Sn-down was also reported on Cu(111) and Ag(100), while this reaction did not occur on Au(111) and Au(110) surfaces [28]. On the Ag(111) surface, within the first layer, Sn-up molecules were irreversibly switched to the down position, while on InAs(111), the molecules could be switched

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

• orientation of both planar and nonplanar MPc molecules on oxide substrates such as SiO2 is well known. The molecules were shown to preferably have an edge-on orientation [3][7][9][27][28][29]. In our earlier studies, we have reproducibly obtained different crystallites of PbPc on substrates such as HOPG, Au

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

• the PbPc layer is sandwiched between the conductive graphene layer, which served as a bottom electrode, and the Cr/Au tip (diameter < 35 nm and k = 0.18 N·m−1, MikroMasch, USA), serving as a top electrode. Chemical structure of lead phthalocyanine. (a) Top view and (b) side view of a Pb(II)Pc molecule

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

• changed by changing the used metal (Pt/Pd, Al, Cr, Ag, or Au) [9][10], by using carbon [5], or by changing the thickness of the metal film [9][11][12]. There are two published studies in which wavelength values were generated by using a model that could predict colours by taking into account the

• Au–AAO–Al films, respectively (Figure 1). As expected, the porosity of the nanostructures on the surface was smaller after deposition of Cr or Au. The smallest value was achieved after the deposition of 10 nm of Au. It can be concluded that the size of the nanoparticles is bigger for 10 nm Au than

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

• surface active sites [11][12]. In addition, TiO2 combined with noble metal (e.g., Au, Ag, Pt), nanostructured to form a metal–oxide structure, has been shown to greatly improve the catalytic efficiency of the material [13]. When excited by light, noble metal nanoparticles can exhibit surface plasmon

Structural optical and electrical properties of a transparent conductive ITO/Al–Ag/ITO multilayer contact

• Aliyu Kabiru Isiyaku,
• Ahmad Hadi Ali and
• Nafarizal Nayan

Beilstein J. Nanotechnol. 2020, 11, 695–702, doi:10.3762/bjnano.11.57

• enhances the photoresponse and the rectification properties of the ITO device. Single or double metal thin films of Ag, Al, Ti, Au, Cr, or Ni have been embedded between ITO layers [4][8][14][15][16][17]. Free electrons in the metal/ITO materials accelerate the separation of charge carriers and hence

• overcome by adding a thin layer of Al, Au, Pd, or Cr to the Ag film to improve the adhesion [4][25][26]. Optical and electrical properties of ITO films are enhanced by post-deposition annealing especially at high temperatures [7]. Gulen et al. [27] exposed pure ITO films deposited by sputtering to heat

Electromigration-induced directional steps towards the formation of single atomic Ag contacts

• Atasi Chatterjee,
• Christoph Tegenkamp and
• Herbert Pfnür

Beilstein J. Nanotechnol. 2020, 11, 680–687, doi:10.3762/bjnano.11.55

• only observed for alkali metals, but also in monovalent noble metals such as Ag and Au [10][11]. These experimental findings could be very well correlated with the theoretical simulations of conductance histograms [7][12][13]. The theoretical calculation of conductance histograms is based on the semi

• to see that the contribution from 0.8, i.e., thinning in the [110] direction, is absent in these structures. This result contrasts with a MCBJ experiment using Au nanowires [21], in which all three frequencies were obtained. It matches, however, with the findings of mechanical stretching experiments

• ] direction. The frequency at 0.6 has also been observed before by Mares et al. [10]. It was attributed to relatively stable cross sections due to the formation of diametric orbits. This frequency was found to be very prominent for Ag, less prominent in Cu and absent in Au as observed by the authors of [10

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

• CNPs and large CNP at all plasma concentrations tested, while in the case of small CNPs, aggregation was observed only with 10% of plasma, corresponding to the condition used in in vitro tests, but not in vivo. The latter is in agreement with that recently found on Au nanoparticles by Ho and co-workers

Luminescent gold nanoclusters for bioimaging applications

• Nonappa

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

• were observed in N-acetylglutathione (NAGSH) and N-formylglutathione (NFGSH) ligands. Xie and co-workers reported the synthesis of a bovine serum albumin (BSA)-protected water-soluble Au25 nanocluster (Au-BSA) having a red emission at ca. 640 nm with a PL quantum yield of 6% (Figure 1E,F) [63]. More

• importantly, the Au-BSA NCs are stable under ambient conditions and retain their PL even after drying (Figure 1G,H) allowing for long-term storage [64]. Several other proteins including lysozyme, human serum albumin (HSA) and insulin have been used to prepare inherently luminescent AuNCs [65][66][67][68][69

• are presented. In each section representative early examples along with the recent examples are discussed. Biosensing and imaging of pathogens Chan et al. reported human serum albumin (HSA)-stabilized gold NCs (Au-HSA) for sensing Staphylococcus aureus (SA) and methicillin-resistant Staphylococcus

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

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

• , which allows for a number of additional applications in comparison with similar Au nanoparticles, which have a maximum at around 530 nm [6]. The resonance position is influenced, for example, by size and shape of the nanoparticles and the surrounding medium. This gives the ability to control the

• calculated for the nanoparticles obtained from an initially 3, 5 and 7 nm thick layer, respectively, after annealing at 550 °C for 15 min. In this case, however, it is possible that the edges of the nanostructures have already slightly melted. The authors of this work observed a similar exponent for Au

• size of the metallic nanoparticles is larger than 10 nm, their dielectric functions are known to be independent on the size and to have the values of the bulk material [7]. For instance, a dipole mode can then be excited when ε = −2, which corresponds to λ = 355 nm for Ag and λ = 490 nm for Au. When

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

• -dextran [79] and chitosan [80] have been reported to bind to GNPs in a pH-dependent manner as the energy of the Au–N interaction is intermediate between those of Au–S and Au–O [81]. The affinity of different functional groups to the surface of GNPs decreases in the series Au–S > Au–NH2 > Au–COOH [82

DFT calculations of the structure and stability of copper clusters on MoS₂

• Cara-Lena Nies and
• Michael Nolan

Beilstein J. Nanotechnol. 2020, 11, 391–406, doi:10.3762/bjnano.11.30

• transition metals, as well as Ag and Au. However, most studies have examined single-atom adsorption or adsorbed nanoparticles of noble metals. This means there is a knowledge gap in terms of thin film nucleation on 2D materials. To begin addressing this issue, we present in this paper a first-principles

• had the strongest interaction, with a computed binding energy of 6.57 eV. The preferred adsorption site depends on the adsorbed atom. The majority of atoms prefers to adsorb above Mo, including Cu, C and Mg. Mn and Ag prefer to adsorb at a hollow site of the Mo–S hexagon, and Au and O adsorb atop the

• the targeted battery applications [30]. Studies of the adsorption of larger structures include the adsorption of 1D metal chains of Cu, Ag and Au [24] on a monolayer of graphene, in which two different conformations of metal chains, namely zig-zag and armchair, are studied. The metal chains physisorb

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

• deposited downstream nearby the impact spot at a distance of about 10 nm [15]. This small impact accumulation gives rise to the formation of ripples with increasing cluster fluence. Toyoda et al. have studied the influence of incidence angle and cluster size on the ripple formation on Au surfaces. The most

• substrates have been employed, such as Si wafers, bulk Au samples or SiO2 films. There are very few papers on the ripple formation on the surface of confined nanostructures both by monoatomic and cluster ion irradiation. Therefore, in this research we study features of nanoripple formation on the facets of

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

• nanoparticles (metallic gold) are widely applied in the development of biological sensing devices. Gold is an inert metal that exhibits exceptional chemical stability in physiological media and the readiness for surface functionalization with desired biomolecules through stable Au–S bonds. The key properties of

• distributed single-stranded DNA (Au@DNA) through selective hybridization of complementary DNA opened up new possibilities in the development of colorimetric sensors capable of discriminating single-point mutations. This methodology comprised the selective aggregation of two types of noncomplementary DNA

• amplification. Enzyme-free SNP discrimination using gold nanoparticles Although the first works on the selective aggregation of Au@DNA by complementary ssDNA offered a conceptual novelty in the field of biosensing, the simple aggregation of nanoparticles via complementary target DNA suffered from low detection

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

• energy into heat were collected by a suitable optic (Au-coated mirrors, Edmund Optics) and focused on an IR photodetector (HgCdTe photoconductive detector, Kolmar Technologies, KMPV 11-1-J1/DC). Afterwards, a lock-in amplifier (Stanford Research Systems SR865) output the amplitude and phase of the

Fabrication of Ag-modified hollow titania spheres via controlled silver diffusion in Ag–TiO₂ core–shell nanostructures

• Bartosz Bartosewicz,
• Malwina Liszewska,
• Bogusław Budner,
• Marta Michalska-Domańska,
• Krzysztof Kopczyński and
• Bartłomiej J. Jankiewicz

Beilstein J. Nanotechnol. 2020, 11, 141–146, doi:10.3762/bjnano.11.12

• NP-modified TiO2 HSs are based mainly on multistep processes including hard-templating methods [10][11][12][13][14][15][16][17][18][19]. Au-modified TiO2 HSs of regular shape were prepared using a multistep process in which sulfonated polystyrene spheres were used as a hard-template [10]. The

• template was used in the fabrication of rattle-type HSs of Au@TiO2 using multistep template deposition and a surface-protected etching method [13], of TiO2 HSs of mixed anatase/rutile composition loaded with noble metal NPs (Au, Pt, Pd) [14], and of N-doped Ag/TiO2 HSs [15]. A hard-templating method with a

• gradual diminishment of the silver core (DP50 = 113 nm) and the formation of much smaller Ag particles (diameter below 10 nm) on the titania shell surface are observed. The metal diffusion into the titania shell has not been observed in the case of Au@TiO2 CSNs fabricated using the same method as Ag@TiO2

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

• pattern and extent of methylation throughout the genome. In particular, this constituted a promising sensor-free diagnostic platform for the detection of cancer. Chen and co-workers showed that the interaction of DNA with dithiothreitol (DTT)‐conjugated gold nanoclusters (Au NCs) results in the formation

The effect of heat treatment on the morphology and mobility of Au nanoparticles

• Sven Oras,
• Sergei Vlassov,
• Simon Vigonski,
• Boris Polyakov,
• Mikk Antsov,
• Vahur Zadin,
• Rünno Lõhmus and
• Karine Mougin

Beilstein J. Nanotechnol. 2020, 11, 61–67, doi:10.3762/bjnano.11.6

• , Latvia 10.3762/bjnano.11.6 Abstract In the present paper, we investigate the effect of heat treatment on the geometry and mobility of Au nanoparticles (NPs) on a Si substrate. Chemically synthesized Au NPs of diameter ranging from 5 to 27 nm were annealed at 200, 400, 600 and 800 °C for 1 h. A change in

• particles became immovable again. This effect was attributed to the diffusion of Au into the Si substrate and to the growth of the SiO2 layer. Keywords: annealing; atomic force microscopy (AFM); Au nanoparticles; manipulation; melting; nanotribology; Introduction Gold is one of the most prominent

• materials used in studies related to nanostructures. The small size and the enhanced properties of Au nanoparticles (NPs) compared to bulk gold make them important for the development of novel applications, for example, in the field of drug delivery [1], sensor technology [2], printing [3] and catalysis [4