Rigid multipodal platforms for metal surfaces

• Michal Valášek,
• Marcin Lindner and
• Marcel Mayor

Beilstein J. Nanotechnol. 2016, 7, 374–405, doi:10.3762/bjnano.7.34

• scanning probe microscopy [75][81][91], a crosslinker for the creation of arrays of gold nanoparticles, and to anchor several active tail molecules as complex ligands [79][80], fullerenes [77][78][92], rotaxanes [93], pseudorotaxanes and artificial molecular rotors [94][95][96][97] to the surface. Although

• larger tridentate ligands 21 comprising three long alkylsulfanyl chains (C8, C12) and a redox-active ferrocenyl tail group (Figure 10) for the preparation of redox-active SAMs on Au(111) substrates [89]. These tripodal molecules 21 form almost homogeneous, well-ordered, and fairly densely packed SAMs

Early breast cancer screening using iron/iron oxide-based nanoplatforms with sub-femtomolar limits of detection

• Dinusha N. Udukala,
• Hongwang Wang,
• Sebastian O. Wendel,
• Aruni P. Malalasekera,
• Thilani N. Samarakoon,
• Asanka S. Yapa,
• Gayani Abayaweera,
• Matthew T. Basel,
• Pamela Maynez,
• Raquel Ortega,
• Yubisela Toledo,
• Leonie Bossmann,
• Colette Robinson,
• Katharine E. Janik,
• Olga B. Koper,
• Ping Li,
• Massoud Motamedi,
• Daniel A. Higgins,
• Gary Gadbury,
• Gaohong Zhu,
• Deryl L. Troyer and
• Stefan H. Bossmann

Beilstein J. Nanotechnol. 2016, 7, 364–373, doi:10.3762/bjnano.7.33

• characterization of the nanoplatforms for protease detection is described in detail in [19]. In short, water-dispersible Fe/Fe3O4 nanoparticles featuring dopamine ligands [47], TCPP [48], and cyanine 5.5 [49] were synthesized according to established procedures. The oligopeptides used as consensus sequences, which

Time-dependent growth of crystalline Au⁰-nanoparticles in cyanobacteria as self-reproducing bioreactors: 2. Anabaena cylindrica

• Liz M. Rösken,
• Felix Cappel,
• Susanne Körsten,
• Christian B. Fischer,
• Andreas Schönleber,
• Sander van Smaalen,
• Stefan Geimer,
• Christian Beresko,
• Georg Ankerhold and
• Stefan Wehner

Beilstein J. Nanotechnol. 2016, 7, 312–327, doi:10.3762/bjnano.7.30

• [23]. For further use the nanoparticles have to be separated from all the unavoidable molecules present in living organisms, like the biological capping and reducing ligands, e.g., enzymes, chlorophylls, peptides or polyphenols [10][24]. This task is typically quite challenging. Reduction of the toxic

Surface coating affects behavior of metallic nanoparticles in a biological environment

• Darija Domazet Jurašin,
• Marija Ćurlin,
• Ivona Capjak,
• Tea Crnković,
• Marija Lovrić,
• Michal Babič,
• Daniel Horák,
• Ivana Vinković Vrček and
• Srećko Gajović

Beilstein J. Nanotechnol. 2016, 7, 246–262, doi:10.3762/bjnano.7.23

• ligands such as PVP and BSA provide additional steric hindrances. Our results, in accordance with previously published data [48], imply that CIT, PVP and BSA provided colloidal stability for AgNPs irrespective to the type of surface interactions. It is interesting that we have recently observed [49] a

Single-molecule magnet behavior in 2,2’-bipyrimidine-bridged dilanthanide complexes

• Wen Yu,
• Frank Schramm,
• Eufemio Moreno Pineda,
• Yanhua Lan,
• Olaf Fuhr,
• Jinjie Chen,
• Hironari Isshiki,
• Wolfgang Wernsdorfer,
• Wulf Wulfhekel and
• Mario Ruben

Beilstein J. Nanotechnol. 2016, 7, 126–137, doi:10.3762/bjnano.7.15

• -dinuclear complexes of tris-β-diketonate adducts of Gd(III), Tb(III) [30], Dy(III), Ho(III) and Er(III) with a bpm bridging ligand. We employed 2,2’,6,6’-tetramethyl-2,4-heptanedionate (tmhd) ligands as peripheric ligands, providing overall charge-neutral compounds. The magnetic behavior of the compounds

• ligands tris(tetramethylheptanedionato) lanthanide(III) for f-series metal ions results in charge-neutral homo-dinuclear compounds; an aspect potentially important for later deposition of the compounds in device environments by sublimation techniques. Compounds 1–5 were synthesized by adding Ln(tmhd)3 (Ln

• inversion-symmetry-related to each other, resulting in the formation of an achiral meso-form of the polyhedra (see Supporting Information File 1, Figure S1). The bond lengths between the lanthanide ions and the coordinating oxygen and nitrogen atoms of the ligands are summarized in Table 3. They decrease

Simultaneous cancer control and diagnosis with magnetic nanohybrid materials

• Reza Saadat and
• Franz Renz

Beilstein J. Nanotechnol. 2016, 7, 121–125, doi:10.3762/bjnano.7.14

• [Fe(II)(bzimpy)2] (bzimpy = 2,6-bis(benzimidazol-2-yl)pyridine). The resulting MNP cluster can be used as a pH-labile switch: By protonation of the electron pairs of the ligands (which are coordinated to the iron ion) the MNP cluster-stabilizing complex [Fe(II)(bzimpy)2] decomposes [13] in an acidic

Chemiresistive/SERS dual sensor based on densely packed gold nanoparticles

• Sanda Boca,
• Cosmin Leordean,
• Simion Astilean and
• Cosmin Farcau

Beilstein J. Nanotechnol. 2015, 6, 2498–2503, doi:10.3762/bjnano.6.259

• monitoring. Assemblies of gold NPs were recently proposed as chemiresistor sensors, exhibiting reliable responses to the analyzed compounds [4]. In most cases very small particles were used (3–7 nm), functionalized with specific ligands that facilitate their assembly into thin nanoparticle films through

• cross-linked nanoparticle films [6][14]. The effective permittivity in the environment of the nanoparticles can increase due to the adsorption of analytes, which can replace ligands or fill up inter-molecular voids on the surface of the nanoparticles. This can decrease the activation energy for electron

• transfer, which is in turn observed as a resistance decrease. Moreover, in our system MBA is a thiol-terminated molecule while folic acid is not, and therefore one can expect that the MBA molecules can replace folic acid ligands from the surface of the gold particles. MBA is smaller than folic acid, and

Sub-monolayer film growth of a volatile lanthanide complex on metallic surfaces

• Hironari Isshiki,
• Jinjie Chen,
• Kevin Edelmann and
• Wulf Wulfhekel

Beilstein J. Nanotechnol. 2015, 6, 2412–2416, doi:10.3762/bjnano.6.248

• . The films show a distorted three-fold symmetry with a commensurate structure. Scanning tunneling spectroscopy reveals molecular orbitals delocalized on the ligands of the molecule. Our results imply that this complex can be transferred onto the metal substrates without molecular decomposition or

• -dikenonate ligands (see Figure 1) and the total charge of the molecule is zero. Recent DFT calculations for Ln(thd)3 in gas phase show that the D3 symmetry structure corresponds to the minimum of the potential energy [14]. Though remarkable magnetic properties of Ln(thd)3 in bulk have not been reported, some

Surfactant-controlled composition and crystal structure of manganese(II) sulfide nanocrystals prepared by solvothermal synthesis

• Elena Capetti,
• Anna M. Ferretti,
• Vladimiro Dal Santo and
• Alessandro Ponti

Beilstein J. Nanotechnol. 2015, 6, 2319–2329, doi:10.3762/bjnano.6.238

• final NCs: those prepared in absence of amines show the presence of both stearic acid and stearate, whereas in presence of stearic acid and an amine, both stearate and amine (or alkylammonium cation) could be detected although carboxylic acids are usually stronger ligands than amines. The chemistry

Silica-coated upconversion lanthanide nanoparticles: The effect of crystal design on morphology, structure and optical properties

• Uliana Kostiv,
• Miroslav Šlouf,
• Hana Macková,
• Alexander Zhigunov,
• Hana Engstová,
• Katarína Smolková,
• Petr Ježek and
• Daniel Horák

Beilstein J. Nanotechnol. 2015, 6, 2290–2299, doi:10.3762/bjnano.6.235

• (e.g., ethylene glycol) at high temperature and pressure [21][22]. Upconversion particles are typically prepared in different morphologies, sizes and shapes with high surface areas to efficiently conjugate target ligands and drugs [23]. It is important to tailor the surface of the nanoparticles to the

• specific application. Thus, various ligands and functionalities have to be attached to the particle surface to provide efficient drug delivery, to ensure engulfment by the cells, or to control the release of biomolecules and their specific target. Finally, the surface modification must ensure that the

The role of low-energy electrons in focused electron beam induced deposition: four case studies of representative precursors

• Rachel M. Thorman,
• Ragesh Kumar T. P.,
• D. Howard Fairbrother and
• Oddur Ingólfsson

Beilstein J. Nanotechnol. 2015, 6, 1904–1926, doi:10.3762/bjnano.6.194

• cross sections at low incident energies. Good examples of such reactions are the extensive fragmentation of tetrafluorophenol and tetrafluoroaniline [35] as well as that of the commonly used FEBID precursor ligands tri- and hexafluoroacetylacetone [36]. In each of these cases, low energy electron

• molecular hydrogen and ethane enables the otherwise thermochemically inhibited formation of CN− at low incident electron energies. With a suitable choice of ligands, such intramolecular reactions may thus also provide a new means to enhance fragmentation of potential FEBID precursors through DEA. Perhaps

• very low intensity). For the formation of this fragment, the authors proposed a reaction pathway involving the elimination of an ethyl radical via the intramolecular attack of a leaving methyl radical on another methyl ligand and a H-shift from one of the methyl ligands to the central Pt, thereby

Influence of surface chemical properties on the toxicity of engineered zinc oxide nanoparticles to embryonic zebrafish

• Zitao Zhou,
• Jino Son,
• Bryan Harper,
• Zheng Zhou and
• Stacey Harper

Beilstein J. Nanotechnol. 2015, 6, 1568–1579, doi:10.3762/bjnano.6.160

• (lacking surface ligands) are known to cause delayed embryo hatching, developmental abnormalities [12] through dissolution and release of ionic zinc [13][14] as well as induction of DNA damage through generation of reactive oxidative species (ROS) [12][15]. ZnO NPs are often coated with a variety of

• capping agents or surface ligands with differing chemical properties to functionalize the surface and improve stability against agglomeration and dispersibility in a given medium [16]. These surface alterations have the potential to alter their toxicity as a result of differences in the release of Zn2

• ][21]. While the dissolution kinetics and agglomeration state of the ZnO NPs is known to influence the toxicity of the materials, this study aimed to determine if specific intrinsic features could be used in lieu of empirical data on the material’s behaviour. Surface chemical ligands and capping agents

Thermal treatment of magnetite nanoparticles

• Beata Kalska-Szostko,
• Urszula Wykowska,
• Dariusz Satula and
• Per Nordblad

Beilstein J. Nanotechnol. 2015, 6, 1385–1396, doi:10.3762/bjnano.6.143

• MNP-1, surface ligands are rigidly fixed to the sample and do not contain any weakly adsorbed solvents. However, MNP-2 and MNP-3 most likely contain residuals of solvents that gradually evaporate, which is not observed for the samples measured after heat treatment. IR spectroscopy Magnetite

Natural and artificial binders of polyriboadenylic acid and their effect on RNA structure

• Giovanni N. Roviello,
• Domenica Musumeci,
• Valentina Roviello,
• Marina Pirtskhalava,
• Alexander Egoyan and
• Merab Mirtskhulava

Beilstein J. Nanotechnol. 2015, 6, 1338–1347, doi:10.3762/bjnano.6.138

• ]. Since, as explained above, the poly(rA) plays a crucial role in maturation and stabilisation of RNA (as well as in the promotion of the translation process), ligands that selectively bind the poly(rA) tail could affect the function of cellular mRNA. This consequently influences the production of

• on the different binding modes between RNA and the ligands, also clarifying the influence of the ligand substituents on the formation of the RNA–drug complexes. This leads to models useful for the discovery of novel compounds suitable as modulating agents of poly(rA) structure (see the corresponding

• (rA)·poly(rU) triple helix (the symbol “×” indicates Hoogsteen base pairing) through different biophysical and calorimetric techniques. In all cases, the ligands bound the triple helix in a non-cooperative manner with affinities of about 105 M−1, in the case of berberine and palmatine, and 106 M−1 in

Heterometal nanoparticles from Ru-based molecular clusters covalently anchored onto functionalized carbon nanotubes and nanofibers

• Deborah Vidick,
• Xiaoxing Ke,
• Michel Devillers,
• Claude Poleunis,
• Arnaud Delcorte,
• Pietro Moggi,
• Gustaaf Van Tendeloo and
• Sophie Hermans

Beilstein J. Nanotechnol. 2015, 6, 1287–1297, doi:10.3762/bjnano.6.133

• the nanocarbon surface. The ligands of the anchored molecular species are then removed by gentle thermal treatment in order to form nanoparticles. In the case of Au-containing clusters, removal of gold atoms from the clusters and agglomeration leads to a bimodal distribution of nanoparticles at the

• molecular mixed-metal clusters as precursors for depositing heterometal nanoparticles on carbon nanotubes and nanofibers. The advantages of such precursors are that they present well-defined molecular structures and exchangeable ligands, the metal atoms are in the zero oxidation state and bimetal

• counterion, bis(triphenylphosphine)iminium (PPN+), giving the formula PPN[Ru3Co(CO)13]. It is known that all these clusters can exchange CO or COD ligands with phosphine ligands [37]. In addition, the negatively charged Ru–Co species can also interact with a support functionalized with positively charged

Nano-contact microscopy of supracrystals

• Adam Sweetman,
• Nicolas Goubet,
• Ioannis Lekkas,
• Marie Paule Pileni and
• Philip Moriarty

Beilstein J. Nanotechnol. 2015, 6, 1229–1236, doi:10.3762/bjnano.6.126

• intra-nanocrystal features is challenging for a number of reasons. First, the exact nature of our tip apex is unknown, and very possibly terminated either by free thiol ligands or entire nanocrystals. Second, due to the high aspect ratio of the nanocrystal surface (as compared to an atomically flat

Synthesis, characterization and in vitro effects of 7 nm alloyed silver–gold nanoparticles

• Simon Ristig,
• Svitlana Chernousova,
• Wolfgang Meyer-Zaika and
• Matthias Epple

Beilstein J. Nanotechnol. 2015, 6, 1212–1220, doi:10.3762/bjnano.6.124

• the nanoparticles, which can be achieved by variation of the amount of reducing agent. For further stabilization, the ligands can be easily exchanged without affecting the purity of the resulting dispersion. In this case, citrate and tannin were replaced by the frequently used stabilizer, poly

• reducing agents (citrate and tannic acid) were used to generate nanoparticles with mean diameters of 6 to 7 nm. The primary ligands, citrate and tannic acid, were replaced by PVP after the synthesis. For comparison, pure gold and silver nanoparticles were synthesized with the same reaction parameters. The

Improved optical limiting performance of laser-ablation-generated metal nanoparticles due to silica-microsphere-induced local field enhancement

• Zheren Du,
• Lianwei Chen,
• Tsung-Sheng Kao,
• Mengxue Wu and
• Minghui Hong

Beilstein J. Nanotechnol. 2015, 6, 1199–1204, doi:10.3762/bjnano.6.122

• duration, and laser fluence) and the properties of the environment (e.g., surfactant concentration, pH value, or size and length of ligands) [1][2][3][4][5][6]. Laser ablation is an explosive material removal process using strong pulsed-laser irradiation. The LAL process causes the ejection of nanoclusters

Charge carrier mobility and electronic properties of Al(Op)₃: impact of excimer formation

• Andrea Magri,
• Pascal Friederich,
• Bernhard Schäfer,
• Valeria Fattori,
• Xiangnan Sun,
• Timo Strunk,
• Velimir Meded,
• Luis E. Hueso,
• Wolfgang Wenzel and
• Mario Ruben

Beilstein J. Nanotechnol. 2015, 6, 1107–1115, doi:10.3762/bjnano.6.112

• very reason we have synthesized and studied the phenalenyl-based alternative, OSC tris(1-oxo-1H-phenalen-9-olate)aluminum(III) (Al(Op)3) (see Figure 1), which is formed by ligands with an extended aromatic system. The expected result is an increased capability to accept and efficiently delocalize

• . In this work, the potential of the chemical tailoring of the aluminum complexes’ ligands was successfully demonstrated along with the resulting effects on the electronic properties of the hybrid interfaces. To our knowledge, this is surprisingly the first time that the electronic properties of Al(Op

• problem at hand, we performed density functional-based [36][37][38] calculations for both a single molecule in vacuum and molecules embedded in an explicit matrix [39] and compared them to a de facto standard in the field, namely, Alq3. Structurally, Al(Op)3 is formed by symmetric ligands that bind to the

Protein corona – from molecular adsorption to physiological complexity

• Lennart Treuel,
• Dominic Docter,
• Michael Maskos and
• Roland H. Stauber

Beilstein J. Nanotechnol. 2015, 6, 857–873, doi:10.3762/bjnano.6.88

• . Focusing on the NP, ligand exchange under physiological conditions is an important point. Many ligands can easily be replaced on NP surfaces in equilibrium exchange-reactions [13]. Such approaches are frequently utilized in NP synthesis, in which specific ligands are often needed to synthesize NPs with

• desired properties, but are subsequently replaced by other ligands, e.g., to alter the solubility or avoid adverse effects related to toxic ligands [13][14][15][16]. Protein adsorption can well lead to the exchange of small monomer-type ligands on NP surfaces under physiological conditions while other

• . While polymer coatings are regarded as relatively stable under such conditions, other ligands can well be replaced in equilibrium-type reactions, even under chemically less complex conditions [13]. It has been discussed before, how the formation of a protein corona can change the surface functionality

Microwave assisted synthesis and characterisation of a zinc oxide/tobacco mosaic virus hybrid material. An active hybrid semiconductor in a field-effect transistor device

• Shawn Sanctis,
• Rudolf C. Hoffmann,
• Sabine Eiben and
• Jörg J. Schneider

Beilstein J. Nanotechnol. 2015, 6, 785–791, doi:10.3762/bjnano.6.81

• characteristic 13C chemical shift corresponding to the formation of acetonitrile (δ = 117.30 ppm) under post decomposition conditions of the precursor complex. Additional chemical shifts from still coordinated as well as from residual free ligands were also present as expected due to the base-catalyzed

• materials with functional properties that can be implemented into future device applications. Schematic representation of the microwave decomposition pathway of the zinc oximato precursor in the presence of TEAOH as a base based on NMR spectroscopy. Note that the water ligands are omitted in the starting

Influence of gold, silver and gold–silver alloy nanoparticles on germ cell function and embryo development

• Ulrike Taylor,
• Daniela Tiedemann,
• Christoph Rehbock,
• Wilfried A. Kues,
• Stephan Barcikowski and
• Detlef Rath

Beilstein J. Nanotechnol. 2015, 6, 651–664, doi:10.3762/bjnano.6.66

• were given. In the latter the concentration indicating the onset of adverse effects was higher than in the experiments we conducted. Furthermore, both experiments were run using nanoparticles produced by chemical means, which could lead to residual stabilizing ligands remaining from synthesis, still

Nanoparticle shapes by using Wulff constructions and first-principles calculations

• Georgios D. Barmparis,
• Zbigniew Lodziana,
• Nuria Lopez and
• Ioannis N. Remediakis

Beilstein J. Nanotechnol. 2015, 6, 361–368, doi:10.3762/bjnano.6.35

• larger nanoparticles that are clearly out of equilibrium. However, it was recently found that when complex ligands are attached to their surfaces, nanoparticles may have equilibrium shapes that do not belong in the same point group as the material (see section about ligands below). Wulff construction in

• additions to the method can account for detailed atomistic structure of the nanoparticles, including coordination numbers of their atoms and density of active sites, while it can even take into account complex crystal structures and attached ligands. As such, it is expected to play a key role within

Comparative evaluation of the impact on endothelial cells induced by different nanoparticle structures and functionalization

• Lisa Landgraf,
• Ines Müller,
• Peter Ernst,
• Miriam Schäfer,
• Christina Rosman,
• Isabel Schick,
• Oskar Köhler,
• Hartmut Oehring,
• Vladimir V. Breus,
• Thomas Basché,
• Carsten Sönnichsen,
• Wolfgang Tremel and
• Ingrid Hilger

Beilstein J. Nanotechnol. 2015, 6, 300–312, doi:10.3762/bjnano.6.28

• further functionalization three different ligands for CdSe/4 ZnS core–shell QDs (d = 5.4 nm) were selected: 3-mercaptopropionic acid/MPA (COOH), cysteamine/CyA (NH2), D-penicillamine/DPA (NH2/COOH). These coatings represent neutral, positive or negative charge and provide the solubility in water. The

The effect of surface charge on nonspecific uptake and cytotoxicity of CdSe/ZnS core/shell quantum dots

• Vladimir V. Breus,
• Anna Pietuch,
• Marco Tarantola,
• Thomas Basché and
• Andreas Janshoff

Beilstein J. Nanotechnol. 2015, 6, 281–292, doi:10.3762/bjnano.6.26

• biotinylated QDs [30], or to observe the movement of single, streptavidin-coated QDs along microtubules [31]. Results and Discussion ECIS and the MTS assay were used to evaluate the viability of MDCKII cells exposed to CdSe/ZnS QDs functionalized with positively-charged CA ligands, negatively-charged DHLA- or

• MPA-ligands, and zwitterionic DPA ligands (Scheme 1). At physiological pH 7.4, CA–QDs exhibit high aggregation rates in aqueous solutions, with hydrodynamic diameters 4–5 times larger than those of the as-prepared particles with the initial coating in organic solution [11]. In contrast, DHLA–QDs and

• cooled down to room temperature with compressed air flow. The resulting core/shell QDs were precipitated with ethanol, centrifuged and redissolved in chloroform. QD surface functionalization Table 1 summarizes the amounts of ligands and solvents used for QD surface functionalization. The amount of