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  • 1.
    Bano, Fouzia
    et al.
    ELETTRA, Sincrotrone Trieste; Scuola Internazionale Superiore di Studi Avanzati (SISSA).
    Fruk, Ljiljana
    Sanavio, Barbara
    Glettenberg, Maximilian
    Casalis, Loredana
    Niemeyer, Christof M.
    Scoles, Giacinto
    Toward multiprotein nanoarrays using nanografting and DNA directed immobilization of proteins2009In: Nano Letters, ISSN 1530-6984, E-ISSN 1530-6992, Vol. 9, no 7, p. 2614-2618Article in journal (Refereed)
    Abstract [en]

    Atomic force microscopy nanografting was utilized to prepare DNA nanopatches of different sizes (200 × 200 to 1000 × 1000 nm2) onto which DNA−protein conjugates can be anchored through DNA-directed immobilization. Height measurements were used to assess the binding of the proteins as well as their subsequent interaction with other components, such as antibodies. The results indicate that nanografted patch arrays are well suited for application in biosensing and could enable the fabrication of multifeature protein nanoarrays.

  • 2.
    Barzegar, Hamid Reza
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA.
    Gracia Espino, Eduardo
    Umeå University, Faculty of Science and Technology, Department of Physics. Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Wågberg, Thomas
    Umeå University, Faculty of Science and Technology, Department of Physics.
    C60/Collapsed Carbon Nanotube Hybrids: A Variant of Peapods2015In: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 15, no 2, p. 829-834Article in journal (Refereed)
    Abstract [en]

    We examine a variant of so-called carbon nanotube peapods by packing C60 molecules inside the open edge ducts of collapsed carbon nanotubes. C60 insertion is accomplished through a facile single-step solution-based process. Theoretical modeling is used to evaluate favorable low-energy structural configurations. Overfilling of the collapsed tubes allows infiltration of C60 over the full cross-section of the tubes and consequent partial or complete reinflation, yielding few-wall, large diameter cylindrical nanotubes packed with crystalline C60 solid cores.

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  • 3.
    Barzegar, Hamid Reza
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics. Department of Physics, University of California, Berkeley, California 94720, United States ‡ Department of Physics, Umeå University, SE-901 87 Umeå, Sweden § Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States ∥ Kavli Energy NanoSciences Institute at the University of California, Berkeley and the Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
    Larsen, Christian
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Boulanger, Nicolas
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Zettl, Alex
    Department of Physics, University of California, Berkeley, California 94720, United States.
    Edman, Ludvig
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Wågberg, Thomas
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Self-assembled PCBM nanosheets: a facile route to electronic layer-on-Layer heterostructures2018In: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 18, no 2, p. 1442-1447Article in journal (Refereed)
    Abstract [en]

    We report on the self-assembly of semicrystalline [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) nanosheets at the interface between a hydrophobic solvent and water, and utilize this opportunity for the realization of electronically active organic/organic molecular heterostructures. The self-assembled PCBM nanosheets can feature a lateral size of >1 cm2 and be transferred from the water surface to both hydrophobic and hydrophilic surfaces using facile transfer techniques. We employ a transferred single PCBM nanosheet as the active material in a field-effect transistor (FET) and verify semiconductor function by a measured electron mobility of 1.2 × 10–2 cm2 V–1 s–1 and an on–off ratio of ∼1 × 104. We further fabricate a planar organic/organic heterostructure with the p-type organic semiconductor poly(3-hexylthiophene-2,5-diyl) as the bottom layer and the n-type PCBM nanosheet as the top layer and demonstrate ambipolar FET operation with an electron mobility of 8.7 × 10–4 cm2 V–1 s–1 and a hole mobility of 3.1 × 10–4 cm2V–1 s–1.

  • 4.
    Barzegar, Hamid Reza
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA; Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA; Univ Calif Berkeley, Kavli Energy NanoSci Inst, Berkeley, CA 94720 USA; Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA.
    Yan, Aiming
    Coh, Sinisa
    Gracia-Espino, Eduardo
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Dunn, Gabriel
    Wågberg, Thomas
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Louie, Steven G.
    Cohen, Marvin L.
    Zettl, Alex
    Electrostatically Driven Nanoballoon Actuator2016In: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 16, no 11, p. 6787-6791Article in journal (Refereed)
    Abstract [en]

    We demonstrate an inflatable nanoballoon actuator based on geometrical transitions between the inflated (cylindrical) and collapsed (flattened) forms of a carbon nanotube. In situ transmission electron microscopy experiments employing a nanoelectromechanical manipulator show that a collapsed carbon nanotube can be reinflated by electrically charging the nanotube, thus realizing an electrostatically driven nanoballoon actuator. We find that the tube actuator can be reliably cycled with only modest control voltages (few volts) with no apparent wear or fatigue. A complementary theoretical analysis identifies critical parameters for nanotube nanoballoon actuation.

  • 5.
    Brown, Keith A.
    et al.
    Department of Mechanical Engineering, Physics Department, and Division of Materials Science and Engineering, Boston University, Boston, Massachusetts 02215, United States.
    Brittman, Sarah
    U.S. Naval Research Laboratory, Washington, DC 20375, United States.
    Maccaferri, Nicolò
    Department of Physics and Materials Science, University of Luxembourg, 162a avenue de la Faïencerie, L-1511 Luxembourg, Luxembourg.
    Jariwala, Deep
    Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.
    Celano, Umberto
    imec, Kapeldreef 75, B-3001 Heverlee (Leuven), Belgium.
    Machine Learning in Nanoscience: Big Data at Small Scales2019In: Nano Letters, ISSN 1530-6984, E-ISSN 1530-6992, Vol. 20, no 1, p. 2-10Article, review/survey (Refereed)
    Abstract [en]

    Recent advances in machine learning (ML) offer new tools to extract new insights from large data sets and to acquire small data sets more effectively. Researchers in nanoscience are experimenting with these tools to tackle challenges in many fields. In addition to ML's advancement of nanoscience, nanoscience provides the foundation for neuromorphic computing hardware to expand the implementation of ML algorithms. In this Mini Review, we highlight some recent efforts to connect the ML and nanoscience communities by focusing on three types of interaction: (1) using ML to analyze and extract new insights from large nanoscience data sets, (2) applying ML to accelerate material discovery, including the use of active learning to guide experimental design, and (3) the nanoscience of memristive devices to realize hardware tailored for ML. We conclude with a discussion of challenges and opportunities for future interactions between nanoscience and ML researchers.

  • 6.
    Celano, U.
    et al.
    imec, Kapeldreef 75, B-3001 Heverlee (Leuven), Belgium.
    Maccaferri, Nicolò
    Physics and Materials Science Research Unit, University of Luxembourg, 162a avenue de la Faïencerie L-1511 Luxembourg, Luxembourg.
    Chasing Plasmons in Flatland2019In: Nano Letters, ISSN 1530-6984, E-ISSN 1530-6992, Vol. 19, no 11, p. 7549-7552Article, review/survey (Refereed)
    Abstract [en]

    Two-dimensional layered crystals, including graphene and transition metal dichalcogenides, represent an interesting avenue for studying light-matter interactions at the nanoscale in confined geometries. They offer several attractive properties, such as large exciton binding energies, strong excitonic resonances, and tunable bandgaps from the visible to the near-IR along with large spin-orbit coupling, direct band gap transitions, and valley-selective responses.

  • 7. Ekeroth, Sebastian
    et al.
    Münger, E. Peter
    Boyd, Robert
    Ekspong, Joakim
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Wågberg, Thomas
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Edman, Ludvig
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Brenning, Nils
    Helmersson, Ulf
    Catalytic nanotruss structures realized by magnetic self-assembly in pulsed plasma2018In: Nano Letters, ISSN 1530-6984, E-ISSN 1530-6992, Vol. 18, no 5, p. 3132-3137Article in journal (Refereed)
    Abstract [en]

    Tunable nanostructures that feature a high surface area are firmly attached to a conducting substrate and can be fabricated efficiently over significant areas, which are of interest for a wide variety of applications in, for instance, energy storage and catalysis. We present a novel approach to fabricate Fe nanoparticles using a pulsed-plasma process and their subsequent guidance and self-organization into well-defined nanostructures on a substrate of choice by the use of an external magnetic field. A systematic analysis and study of the growth procedure demonstrate that nondesired nanoparticle agglomeration in the plasma phase is hindered by electrostatic repulsion, that a polydisperse nanoparticle distribution is a consequence of the magnetic collection, and that the formation of highly networked nanotruss structures is a direct result of the polydisperse nanoparticle distribution. The nanoparticles in the nanotruss are strongly connected, and their outer surfaces are covered with a 2 nm layer of iron oxide. A 10 μm thick nanotruss structure was grown on a lightweight, flexible and conducting carbon-paper substrate, which enabled the efficient production of H2 gas from water splitting at a low overpotential of 210 mV and at a current density of 10 mA/cm2.

  • 8.
    Enevold, Jenny
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Larsen, Christian
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Zakrisson, Johan
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Andersson, Magnus
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Edman, Ludvig
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Realizing large-area arrays of semiconducting fullerene nanostructures with direct laser interference patterning2018In: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 18, no 1, p. 540-545Article in journal (Refereed)
  • 9.
    Garoli, Denis
    et al.
    Istituto Italiano di Tecnologia, via Morego 30, I-16163, Genova, Italy.
    Yamazaki, Hirohito
    Department of Physics, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 02115, United States.
    Maccaferri, Nicolò
    Physics and Materials Science Research Unit, University of Luxembourg, 162a avenue de la Faïencerie, L-1511 Luxembourg, Luxembourg.
    Wanunu, Meni
    Department of Physics, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 02115, United States.
    Plasmonic Nanopores for Single-Molecule Detection and Manipulation: Toward Sequencing Applications2019In: Nano Letters, ISSN 1530-6984, E-ISSN 1530-6992, Vol. 19, no 11, p. 7553-7562Article, review/survey (Refereed)
    Abstract [en]

    Solid-state nanopore-based sensors are promising platforms for next-generation sequencing technologies, featuring label-free single-molecule sensitivity, rapid detection, and low-cost manufacturing. In recent years, solid-state nanopores have been explored due to their miscellaneous fabrication methods and their use in a wide range of sensing applications. Here, we highlight a novel family of solid-state nanopores which have recently appeared, namely plasmonic nanopores. The use of plasmonic nanopores to engineer electromagnetic fields around a nanopore sensor allows for enhanced optical spectroscopies, local control over temperature, thermophoresis of molecules and ions to/from the sensor, and trapping of entities. This Mini Review offers a comprehensive understanding of the current state-of-the-art plasmonic nano pores for single-molecule detection and biomolecular sequencing applications and discusses the latest advances and future perspectives on plasmonic nano-porebased technologies.

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  • 10.
    Huang, Jian-An
    et al.
    Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy.
    Caprettini, Valeria
    Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy;DIBRIS, University of Genoa, Via all’Opera Pia 13, 16145 Genova, Italy.
    Zhao, Yingqi
    Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy.
    Melle, Giovanni
    Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy;DIBRIS, University of Genoa, Via all’Opera Pia 13, 16145 Genova, Italy.
    Maccaferri, Nicolò
    Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy.
    Deleye, Lieselot
    Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy.
    Zambrana-Puyalto, Xavier
    Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy.
    Ardini, Matteo
    Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy.
    Tantussi, Francesco
    Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy.
    Dipalo, Michele
    Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy.
    De Angelis, Francesco
    Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy.
    On-Demand Intracellular Delivery of Single Particles in Single Cells by 3D Hollow Nanoelectrodes2019In: Nano Letters, ISSN 1530-6984, E-ISSN 1530-6992, Vol. 19, no 2, p. 722-731Article in journal (Refereed)
  • 11. Kong, Dexu
    et al.
    Megone, William
    Nguyen, Khai D. Q.
    Di Cio, Stefania
    Ramstedt, Madeleine
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Gautrot, Julien E.
    Protein nanosheet mechanics controls cell adhesion and expansion on low-viscosity liquids2018In: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 18, no 3, p. 1946-1951Article in journal (Refereed)
    Abstract [en]

    Adherent cell culture typically requires cell spreading at the surface of solid substrates to sustain the formation of stable focal adhesions and assembly of a contractile cytoskeleton. However, a few reports have demonstrated that cell culture is possible on liquid substrates such as silicone and fluorinated oils, even displaying very low viscosities (0.77 cSt). Such behavior is surprising as low viscosity liquids are thought to relax much too fast (<ms) to enable the stabilization of focal adhesions (with lifetimes on the order of minutes to hours). Here we show that cell spreading and proliferation at the surface of low viscosity liquids are enabled by the self-assembly of mechanically strong protein nanosheets at these interfaces. We propose that this phenomenon results from the denaturation of globular proteins, such as albumin, in combination with the coupling of surfactant molecules to the resulting protein nanosheets. We use interfacial rheology and atomic force microscopy indentation to characterize the mechanical properties of protein nanosheets and associated liquid–liquid interfaces. We identify a direct relationship between interfacial mechanics and the association of surfactant molecules with proteins and polymers assembled at liquid–liquid interfaces. In addition, our data indicate that cells primarily sense in-plane mechanical properties of interfaces, rather than relying on surface tension to sustain spreading, as in the spreading of water striders. These findings demonstrate that bulk and nanoscale mechanical properties may be designed independently, to provide structure and regulate cell phenotype, therefore calling for a paradigm shift for the design of biomaterials in regenerative medicine.

  • 12.
    Lodewijks, Kristof
    et al.
    Department of Applied Physics, Chalmers University of Technology, Gothenburg, Sweden.
    Maccaferri, Nicolò
    CIC nanoGUNE Consolider, Donostia / San Sebastian, Spain.
    Pakizeh, Tavakol
    Faculty of Electrical Engineering, K. N. Toosi University of Technology, Tehran, Iran.
    Dumas, Randy K.
    Department of Physics, University of Gothenburg, Gothenburg, Sweden.
    Zubritskaya, Irina
    Department of Applied Physics, Chalmers University of Technology, Gothenburg, Sweden.
    Åkerman, Johan
    Department of Physics, University of Gothenburg, Gothenburg, Sweden;Materials Physics, School of Information and Communication Technology, KTH Royal Institute of Technology, 16440 Kista, Sweden.
    Vavassori, Paolo
    CIC nanoGUNE Consolider, Donostia / San Sebastian, Spain;IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain.
    Dmitriev, Alexandre
    Department of Applied Physics, Chalmers University of Technology, Gothenburg, Sweden.
    Magnetoplasmonic Design Rules for Active Magneto-Optics2014In: Nano Letters, ISSN 1530-6984, E-ISSN 1530-6992, Vol. 14, no 12, p. 7207-7214Article in journal (Refereed)
    Abstract [en]

    Light polarization rotators and nonreciprocal optical isolators are essential building blocks in photonics technology. These macroscopic passive devices are commonly based on magneto-optical Faraday and Kerr polarization rotation. Magnetoplasmonics, the combination of magnetism and plasmonics, is a promising route to bring these devices to the nanoscale. We introduce design rules for highly tunable active magnetoplasmonic elements in which we can tailor the amplitude and sign of the Kerr response over a broad spectral range.

  • 13.
    Maccaferri, Nicolò
    et al.
    CIC nanoGUNE, Donostia-SanSebastian, Spain.
    Bergamini, Luca
    Department of Electricityand Electronics, Faculty of Science and Technology, UPV/EHU, Bilbao, Spain; Materials PhysicsCenter CSIC-UPV/EHU and Donostia International Physics Center, DIPC, Donostia-San Sebastian, Spain.
    Pancaldi, Matteo
    CIC nanoGUNE, Donostia-SanSebastian, Spain.
    Schmidt, Mikolaj K.
    Materials PhysicsCenter CSIC-UPV/EHU and Donostia International Physics Center, DIPC, Donostia-San Sebastian, Spain.
    Kataja, Mikko
    NanoSpin,Department of Applied Physics, Aalto University School of Science, Aalto, Finland.
    Dijken, Sebastiaan van
    NanoSpin,Department of Applied Physics, Aalto University School of Science, Aalto, Finland.
    Zabala, Nerea
    Department of Electricityand Electronics, Faculty of Science and Technology, UPV/EHU, Bilbao, Spain; Materials PhysicsCenter CSIC-UPV/EHU and Donostia International Physics Center, DIPC, Donostia-San Sebastian, Spain.
    Aizpurua, Javier
    Materials PhysicsCenter CSIC-UPV/EHU and Donostia International Physics Center, DIPC, Donostia-San Sebastian, Spain.
    Vavassori, Paolo
    CIC nanoGUNE, Donostia-SanSebastian, Spain; Ikerbasque, Basque Foundation for Science, Bilbao, Spain.
    Anisotropic Nanoantenna-Based Magnetoplasmonic Crystals for Highly Enhanced and Tunable Magneto-Optical Activity2016In: Nano Letters, ISSN 1530-6984, E-ISSN 1530-6992, Vol. 16, no 4, p. 2533-2542Article in journal (Refereed)
    Abstract [en]

    We present a novel concept of a magnetically tunable plasmonic crystal based on the excitation of Fano lattice surface modes in periodic arrays of magnetic and optically anisotropic nanoantennas. We show how coherent diffractive far-field coupling between elliptical nickel nanoantennas is governed by the two in-plane, orthogonal and spectrally detuned plasmonic responses of the individual building block, one directly induced by the incident radiation and the other induced by the application of an external magnetic field. The consequent excitation of magnetic field-induced Fano lattice surface modes leads to highly tunable and amplified magneto-optical effects as compared to a continuous film or metasurfaces made of disordered noninteracting magnetoplasmonic anisotropic nanoantennas. The concepts presented here can be exploited to design novel magnetoplasmonic sensors based on coupled localized plasmonic resonances, and nanoscale metamaterials for precise control and magnetically driven tunability of light polarization states.

  • 14.
    Maccaferri, Nicolò
    et al.
    Department of Physics and Materials Science, Université du Luxembourg, Luxembourg, Luxembourg.
    Meuret, Sophie
    CEMES, CNRS − UPR8011, Université de Toulouse, Toulouse, France.
    Kornienko, Nikolay
    Department of Chemistry, Université de Montréal, Montreal, Quebec, Canada.
    Jariwala, Deep
    Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
    Speeding up Nanoscience and Nanotechnology with Ultrafast Plasmonics2020In: Nano Letters, ISSN 1530-6984, E-ISSN 1530-6992, Vol. 20, no 8, p. 5593-5596Article, review/survey (Refereed)
    Abstract [en]

    Surface plasmons are collective oscillations of free electrons at the interface between a conducting material and the dielectric environment. These excitations support the formation of strongly enhanced and confined electromagnetic fields. As well, they display fast dynamics lasting tens of femtoseconds and can lead to a strong nonlinear optical response at the nanoscale. Thus, they represent the perfect tool to drive and control fast optical processes, such as ultrafast optical switching, single photon emission, as well as strong coupling interactions to explore and tailor photochemical reactions. In this Virtual Issue, we gather several important papers published in Nano Letters in the past decade reporting studies on the ultrafast dynamics of surface plasmons.

  • 15.
    Maccaferri, Nicolò
    et al.
    Istituto Italiano di Tecnologia, Via Morego 30, 16163, Genova, Italy.
    Zhao, Yingqi
    Istituto Italiano di Tecnologia, Via Morego 30, 16163, Genova, Italy.
    Isoniemi, Tommi
    Istituto Italiano di Tecnologia, Via Morego 30, 16163, Genova, Italy.
    Iarossi, Marzia
    Istituto Italiano di Tecnologia, Via Morego 30, 16163, Genova, Italy;DIBRIS, Università degli Studi di Genova, Via Balbi 5, 16126 Genova, Italy.
    Parracino, Antonietta
    Istituto Italiano di Tecnologia, Via Morego 30, 16163, Genova, Italy.
    Strangi, Giuseppe
    Istituto Italiano di Tecnologia, Via Morego 30, 16163, Genova, Italy;Department of Physics, Case Western Reserve University, 10600 Euclid Avenue, Cleveland, Ohio 44106, United States;CNR-NANOTEC Istituto di Nanotecnologia and Department of Physics, University of Calabria, Arcavacata 87036, Italy.
    De Angelis, Francesco
    Istituto Italiano di Tecnologia, Via Morego 30, 16163, Genova, Italy.
    Hyperbolic Meta-Antennas Enable Full Control of Scattering and Absorption of Light2019In: Nano Letters, ISSN 1530-6984, E-ISSN 1530-6992, Vol. 19, no 3, p. 1851-1859Article in journal (Refereed)
    Abstract [en]

    We introduce a novel concept of hybrid metal-dielectric meta-antenna supporting type II hyperbolic dispersion, which enables full control of absorption and scattering of light in the visible/near-infrared spectral range. This ability lies in the different nature of the localized hyperbolic Bloch-like modes excited within the meta-antenna. The experimental evidence is corroborated by a comprehensive theoretical study. In particular, we demonstrate that two main modes, one radiative and one non-radiative, can be excited by direct coupling with the free-space radiation. We show that the scattering is the dominating electromagnetic decay channel, when an electric dipolar mode is induced in the system, whereas a strong absorption process occurs when a magnetic dipole is excited. Also, by varying the geometry of the system, the relative ratio of scattering and absorption, as well as their relative enhancement and/or quenching, can be tuned at will over a broad spectral range, thus enabling full control of the two channels. Importantly, both radiative and nonradiative modes supported by our architecture can be excited directly with far field radiation. This is observed to occur even when the radiative channels (scattering) are almost totally suppressed, thereby making the proposed architecture suitable for practical applications. Finally, the hyperbolic meta-antennas possess both angular and polarization independent structural integrity, unlocking promising applications as hybrid meta-surfaces or as solvable nanostructures.

  • 16. Mirmomtaz, Elham
    et al.
    Castronovo, Matteo
    Grunwald, Christian
    Bano, Fouzia
    ELETTRA, Sincrotrone Trieste S.C.p.A; Scuola Internazionale Superiore di Studi Avanzati (SISSA).
    Scaini, Denis
    Ensafi, Ali A.
    Scoles, Giacinto
    Casalis, Loredana
    Quantitative study of the effect of coverage on the hybridization efficiency of surface-bound DNA nanostructures2008In: Nano Letters, ISSN 1530-6984, E-ISSN 1530-6992, Vol. 8, no 12, p. 4134-4139Article in journal (Refereed)
    Abstract [en]

    We demonstrate that, contrary to current understanding, the density of probe molecules is not responsible for the lack of hybridization in high density single-stranded DNA (ss-DNA) self-assembled monolayers (SAMs). To this end, we use nanografting to fabricate well packed ss-DNA nanopatches within a “carpet matrix” SAM of inert thiols on gold surfaces. The DNA surface density is varied by changing the “writing” parameters, for example, tip speed, and number of scan lines. Since ss-DNA is 50 times more flexible than ds-DNA, hybridization leads to a transition to a “standing up” phase. Therefore, accurate height and compressibility measurements of the nanopatches before and after hybridization allow reliable, sensitive, and label-free detection of hybridization. Side-by-side comparison of self-assembled and nanografted DNA-monolayers shows that the latter, while denser than the former, display higher hybridization efficiencies.

  • 17. Rezania, B.
    et al.
    Severin, Nikolai
    Talyzin, Alexandr V.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Rabe, Juergen P.
    Hydration of bilayered graphene oxide2014In: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 14, no 7, p. 3993-3998Article in journal (Refereed)
    Abstract [en]

    The hydration of graphene oxide (GO) membranes is the key to understand their remarkable selectivity in permeation of water molecules and humidity-dependent gas separation. We investigated the hydration of single GO layers as a function of humidity using scanning force microscopy, and we determined the single interlayer distance from the step height of a single GO layer on top of one or two GO layers. This interlayer distance grows gradually by approximately 1 A upon a relative humidity (RH) increase in the range of 2 to similar to 80% and the immersion into liquid water increases the interlayer distance further by another 3 A. The gradual expansion of the single interlayer distance is in good agreement with the averaged distance measured by X-ray diffraction on multilayered graphite oxides, which is commonly explained with an interstratification model. However, our experimental design excludes effects connected to interstratification. Instead we determine directly if insertion of water into GO occurs strictly by monolayers or the thickness of GO layers changes gradually. We find that hydration with up to 80% RH is a continuous process of incorporation of water molecules into single GO layers, while liquid water inserts as monolayers. The similarity of hydration for our bilayer and previously reported multilayered materials implies GO few and even bilayers to be suitable for selective water transport.

  • 18.
    Sharifi, Tiva
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics. Department of Material Science and Nanoengineering, Rice University, Houston, Texas, United States.
    Zhang, Xiang
    Costin, Gelu
    Yazdi, Sadegh
    Woellner, Cristiano F.
    Liu, Yang
    Tiwary, Chandra Sekhar
    Ajayan, Pulickel
    Thermoelectricity Enhanced Electrocatalysis2017In: Nano Letters, ISSN 1530-6984, E-ISSN 1530-6992, Vol. 17, no 12, p. 7908-7913Article in journal (Refereed)
    Abstract [en]

    We show that thermoelectric materials can function as electrocatalysts and use thermoelectric voltage generated to initiate and boost electrocatalytic reactions. The electrocatalytic activity is promoted by the use of nanostructured thermoelectric materials in a hydrogen evolution reaction (HER) by the thermoelectricity generated from induced temperature gradients. This phenomenon is demonstrated using two-dimensional layered thermoelectric materials Sb2Te3 and Bi0.5Sb1.5Te3 where a current density approaching ∼50 mA/cm2 is produced at zero potential for Bi0.5Sb1.5Te3 in the presence of a temperature gradient of 90 °C. In addition, the turnover frequency reaches to 2.7 s–1 at 100 mV under this condition which was zero in the absence of temperature gradient. This result adds a new dimension to the properties of thermoelectric materials which has not been explored before and can be applied in the field of electrocatalysis and energy generation.

  • 19.
    Talyzin, Alexandr
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Anoshkin, Ilya
    Aalto University.
    Krasheninnikov, Arkady
    Aalto University.
    Nieminen, Risto
    Nasibulin, Albert
    Aalto University.
    Jiang, Hua
    Aalto University.
    Kauppinen, Esko
    Aalto University.
    Synthesis of Graphene Nanoribbons Encapsulated in Single-Walled Carbon Nanotubes2011In: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 11, no 10, p. 4352-4356Article in journal (Refereed)
    Abstract [en]

    A novel material, graphene nanoribbons encapsulated in single-walled carbon nanotubes (GNR@SWNT), was synthesized using confined polymerization and fusion of polycyclic aromatic hydrocarbon (PAH) molecules. Formation of the GNR is possible due to confinement effects provided by the one-dimensional space inside nanotubes, which helps to align coronene or perylene molecules edge to edge to achieve dimerization and oligomerization of the molecules into long nanoribbons. Almost 100% filling of SWNT with GNR is achieved while nanoribbon length is limited only by the length of the encapsulating nanotube. The PAH fusion reaction provides a very simple and easily scalable method to synthesize GNR@SWNT in macroscopic amounts. First-principle simulations indicate that encapsulation of the GNRs is energetically favorable and that the electronic structure of the encapsulated GNRs is the same as for the free-standing ones, pointing to possible applications of the GNR@SWNT structures in photonics and nanoelectronics.

  • 20.
    Zubritskaya, Irina
    et al.
    Department of Applied Physics, Chalmers University of Technology, Göteborg 41296, Sweden.
    Lodewijks, Kristof
    Department of Applied Physics, Chalmers University of Technology, Göteborg 41296, Sweden.
    Maccaferri, Nicolò
    CIC nanoGUNE, Donostia−SanSebastian 20018, Spain.
    Mekonnen, Addis
    Department of Applied Physics, Chalmers University of Technology, Göteborg 41296, Sweden.
    Dumas, Randy K.
    Department of Physics, University of Gothenburg, Gothenburg 412 96, Sweden.
    Åkerman, Johan
    Department of Physics, University of Gothenburg, Gothenburg 412 96, Sweden;Materials Physics, School of Informationand Communication Technology, KTH Royal Institute of Technology, 16440 Kista, Sweden.
    Vavassori, Paolo
    CIC nanoGUNE, Donostia−SanSebastian 20018, Spain;IKERBASQUE, Basque Foundation for Science, Bilbao 48011, Spain.
    Dmitriev, Alexandre
    Department of Applied Physics, Chalmers University of Technology, Göteborg 41296, Sweden.
    Active Magnetoplasmonic Ruler2015In: Nano Letters, ISSN 1530-6984, E-ISSN 1530-6992, Vol. 15, no 5, p. 3204-3211Article in journal (Refereed)
    Abstract [en]

    Plasmon rulers are an emerging concept in which the strong near-field coupling of plasmon nanoantenna elements is employed to Obtain structural information at the nanoscale. Here, we combine nanoplasmonics and nano-magnetism to conceptualize a magnetoplasmonic dimer nanoantenna that would be able to report nanoscale distances While optimizing its own spatial orientation. The latter constitutes an active operation in which a dynamically optimized optical response per measured unit length allows for the measurement of small and large nanoscale distances With about 2 orders of magnitude higher precision than current state-of-the-art plasmon rulers. We further propose,a concept to Optically measure the nanoscale response to the controlled application of force with a magnetic field.

  • 21.
    Zubritskaya, Irina
    et al.
    Departmentof Physics, University of Gothenburg, Gothenburg, Sweden.
    Maccaferri, Nicolò
    CIC nanoGUNE, Donostia−SanSebastian, Spain; Istituto Italiano di Tecnologia, Genova, Italy.
    Inchausti Ezeiza, Xabier
    CIC nanoGUNE, Donostia−SanSebastian, Spain.
    Vavassori, Paolo
    CIC nanoGUNE, Donostia−SanSebastian, Spain; IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
    Dmitriev, Alexandre
    Departmentof Physics, University of Gothenburg, Gothenburg, Sweden; GeballeLaboratory for Advanced Materials, Stanford University, Stanford, California, USA.
    Magnetic Control of the Chiroptical Plasmonic Surfaces2018In: Nano Letters, ISSN 1530-6984, E-ISSN 1530-6992, Vol. 18, no 1, p. 302-307Article in journal (Refereed)
    Abstract [en]

    A major challenge facing plasmon nanophotonics is the poor dynamic tunability. A functional nanophotonic element would feature the real-time sizable tunability of transmission, reflection of light’s intensity or polarization over a broad range of wavelengths, and would be robust and easy to integrate. Several approaches have been explored so far including mechanical deformation, thermal, or refractive index effects, and all-optical switching. Here we devise an ultrathin chiroptical surface, built on two-dimensional nanoantennas, where the chiral light transmission is controlled by the externally applied magnetic field. The magnetic field-induced modulation of the far-field chiroptical response with this surface exceeds 100% in the visible and near-infrared spectral ranges, opening the route for nanometer-thin magnetoplasmonic light-modulating surfaces tuned in real time and featuring a broad spectral response.

1 - 21 of 21
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