Advanced Materials

Cover image for Vol. 19 Issue 11

June, 2007

Volume 19, Issue 11

Pages 1431–1536

  1. Cover Picture

    1. Top of page
    2. Cover Picture
    3. Contents
    4. Reviews
    5. Communications
    6. Research News
    7. Index
    1. Cover Picture: Formation of Well-Organized Self-Assembled Films from Peptide Nanotubes (Adv. Mater. 11/2007)

      N. Hendler, N. Sidelman, M. Reches, E. Gazit, Y. Rosenberg and S. Richter

      Article first published online: 25 MAY 2007 | DOI: 10.1002/adma.200790040

      A method for constructing peptide-nanotube-based films is demonstrated. A centimeter-sized film of diphenylalanine is successfully formed. The formation process includes the dissociation of nanotubes in a polar cosolvent solution and their recrystallization in spherulitic form on solid substrates, while preserving the basic crystallographic structure of the nanotubes (see figure and cover). In addition, silver-embedded peptide nanotube composite networks are created.

  2. Contents

    1. Top of page
    2. Cover Picture
    3. Contents
    4. Reviews
    5. Communications
    6. Research News
    7. Index
  3. Reviews

    1. Top of page
    2. Cover Picture
    3. Contents
    4. Reviews
    5. Communications
    6. Research News
    7. Index
    1. Carbon Nanotube Field-Effect-Transistor-Based Biosensors (pages 1439–1451)

      B. L. Allen, P. D. Kichambare and A. Star

      Article first published online: 30 APR 2007 | DOI: 10.1002/adma.200602043

      Thumbnail image of graphical abstract

      The application of carbon nanotubes in life sciences has advanced rapidly in recent years. This Review focuses on carbon-nanotube-based field-effect transistors (NTFETs, see figure) as novel electrochemical transducers to give ultrasmall and highly sensitive biosensors. Recent examples of applications of NTFET devices for detection of proteins, antibody–antigen assays, DNA hybridization, and enzymatic reactions involving glucose are summarized here.

    2. Nonvolatile Memory Elements Based on Organic Materials (pages 1452–1463)

      J. C. Scott and L. D. Bozano

      Article first published online: 10 MAY 2007 | DOI: 10.1002/adma.200602564

      Thumbnail image of graphical abstract

      Research towards memory technologies has received great attention in the materials science community. The observation of switching and bistability in organic electronic devices (see figure) has spurred the search for materials suitable for nonvolatile memory technology. This Review describes materials and device structures explored over the past 40 years, and discusses the various mechanisms that have been proposed to explain their switching behavior.

  4. Communications

    1. Top of page
    2. Cover Picture
    3. Contents
    4. Reviews
    5. Communications
    6. Research News
    7. Index
    1. Direct Estimate of Transport Length Scales in Semiconducting Polymers (pages 1465–1470)

      D. Kabra and K. S. Narayan

      Article first published online: 10 MAY 2007 | DOI: 10.1002/adma.200602405

      Thumbnail image of graphical abstract

      A method for determining the electron/hole transport length scale of model semiconducting polymer systems by scanning a narrow-light probe beam over the nonoverlapping anode/cathode region in asymmetric sandwich device structures is presented (see figure). Electron versus hole collection efficacy, and disorder and spatial anisotropy in the electrical transport parameters can be estimated.

    2. Optical Detection of Mercury(II) in Aqueous Solutions by Using Conjugated Polymers and Label-Free Oligonucleotides (pages 1471–1474)

      X. Liu, Y. Tang, L. Wang, J. Zhang, S. Song, C. Fan and S. Wang

      Article first published online: 9 MAY 2007 | DOI: 10.1002/adma.200602578

      Thumbnail image of graphical abstract

      A conjugated-polymer-based “mix-and-detect” optical sensor for mercury ions is fabricated by using a water-soluble poly[3-(3′-N,N,N-triethylamino-1′-propyloxy)-4-methyl-2,5-thiophene hydrochloride] (PMNT) and a label-free, mercury-specific oligonucleotide (MSO) probe. PMNT binds to the Hg2+-free MSO and the Hg2+–MSO complex in different ways, and exhibits distinguishable and specific optical responses to the target-induced conformation change.

      Corrected by:

      Correction: Optical Detection of Mercury(II) in Aqueous Solutions by Using Conjugated Polymers and Label-Free Oligonucleotides

      Vol. 19, Issue 13, 1662, Article first published online: 26 JUN 2007

    3. Aqueous Synthesis of Glutathione-Capped ZnSe and Zn1–xCdxSe Alloyed Quantum Dots (pages 1475–1479)

      Y. Zheng, Z. Yang and J. Y. Ying

      Article first published online: 10 MAY 2007 | DOI: 10.1002/adma.200601939

      Thumbnail image of graphical abstract

      Glutathione-capped ZnSe and Zn1–xCdxSe alloyed quantum dots (QDs) have been successfully synthesized in aqueous solution (see figure). Their fluorescence emissions are tunable between 360 and 500 nm. The as-prepared QDs have a quantum yield of up to 50 %, comparable to or better than most QDs prepared by an organometallic route. The approach can be easily scaled up for commercial production of alloyed nanocrystals of various compositions.

    4. Intracellular Trafficking of Carbon Nanotubes by Confocal Laser Scanning Microscopy (pages 1480–1484)

      L. Lacerda, G. Pastorin, D. Gathercole, J. Buddle, M. Prato, A. Bianco and K. Kostarelos

      Article first published online: 10 MAY 2007 | DOI: 10.1002/adma.200601412

      Thumbnail image of graphical abstract

      Intracellular trafficking of ammonium-functionalized single-walled carbon nanotubes reveals that after cell internalization the nanotubes translocate around the cell nucleus of human lung carcinoma cells (A549). The luminescent signal of the carbon nanotubes (no fluorescent labels) is used for 3D intracellular tracking (see figure). The presented methodology is expected to offer a widely usable tool that will further elucidate the intracellular transport mechanisms of carbon nanotubes.

      Corrected by:

      Correction: Intracellular Trafficking of Carbon Nanotubes by Confocal Laser Scanning Microscopy

      Vol. 19, Issue 14, 1789, Article first published online: 6 JUL 2007

    5. Formation of Well-Organized Self-Assembled Films from Peptide Nanotubes (pages 1485–1488)

      N. Hendler, N. Sidelman, M. Reches, E. Gazit, Y. Rosenberg and S. Richter

      Article first published online: 10 MAY 2007 | DOI: 10.1002/adma.200602265

      Thumbnail image of graphical abstract

      A method for constructing peptide-nanotube-based films is demonstrated. A centimeter-sized film of diphenylalanine is successfully formed. The formation process includes the dissociation of nanotubes in a polar cosolvent solution and their recrystallization in spherulitic form on solid substrates, while preserving the basic crystallographic structure of the nanotubes (see figure and cover). In addition, silver-embedded peptide nanotube composite networks are created.

    6. Formation of Biphasic Janus Droplets in a Microfabricated Channel for the Synthesis of Shape-Controlled Polymer Microparticles (pages 1489–1493)

      T. Nisisako and T. Torii

      Article first published online: 30 APR 2007 | DOI: 10.1002/adma.200700272

      Thumbnail image of graphical abstract

      A microfluidic approach is developed for the synthesis of anisotropic particles based on the flow of two immiscible organic phases, a polymerizable phase and a non-polymerizable phase, in a co-flowing aqueous stream within a microchannel. The anisotropic shape originates from the balancing of the interfacial energies between the three phases. The anisotropic particles shown in the figure are obtained by the photopolymerization of the droplets formed in the channels.

    7. A Dynamic Porous Magnet Exhibiting Reversible Guest-Induced Magnetic Behavior Modulation (pages 1494–1498)

      X.-N. Cheng, W.-X. Zhang, Y.-Y. Lin, Y.-Z. Zheng and X.-M. Chen

      Article first published online: 30 APR 2007 | DOI: 10.1002/adma.200700450

      Thumbnail image of graphical abstract

      A flexible 3D porous magnet [KCo7(OH)3(ip)6(H2O)4]·12 H2O based on unprecedented trigonal-prismatic heptanuclear CoII clusters (see figure) is reported to undergo a reversible single-crystal-to-single-crystal transformation on the desorption/adsorption of guest molecules, accompanied by reversible magnetic property changes. This might be applied for the sensing of coordinative, paramagnetic, small molecules such as O2 and NO.

    8. Polymerase Chain Reaction as an Efficient Tool for the Preparation of Block Copolymers (pages 1499–1505)

      M. Safak, F. E. Alemdaroglu, Y. Li, E. Ergen and A. Herrmann

      Article first published online: 4 MAY 2007 | DOI: 10.1002/adma.200700240

      Thumbnail image of graphical abstract

      Generation of well-defined DNA block copolymers with an extended nucleic acid segment (see figure) is achieved by employing the polymerase chain reaction. Characteristics of these di- and triblock architectures are the extremely high molecular weights and the monidispersity of the biological segment. As organic polymers, polyethylene glycol, polypropylene oxide, polystyrene, and poly(N-isopropylacrylamide) are combined with DNA.

    9. Mesoporous Silver Films from Dilute Mixed-Surfactant Solutions by Using Dip-Coating (pages 1506–1509)

      K. Luo, C. T. Walker and K. J. Edler

      Article first published online: 9 MAY 2007 | DOI: 10.1002/adma.200601244

      Thumbnail image of graphical abstract

      Mesoporous silver films (see figure) are synthesized by using a dip-coating method, employing dilute mixed-surfactant solutions, which allows the creation of films over a large area of substrate and uses a smaller amount of surfactant than previous syntheses using lyotropic liquid-crystalline solutions. Ordered 2D hexagonal mesoporous silver films form under conditions of moderate humidity by using photocatalytic reduction.

    10. Triply Periodic Bicontinuous Structures as Templates for Photonic Crystals: A Pinch-off Problem (pages 1510–1514)

      J. H. Moon, Y. Xu, Y. Dan, S.-M. Yang, A. T. Johnson and S. Yang

      Article first published online: 30 APR 2007 | DOI: 10.1002/adma.200700147

      Thumbnail image of graphical abstract

      Triply periodic diamond, cubic, and gyroid structures are studied as templates for the fabrication of 3D photonic crystals (see figure). The achievable backfilling volume fraction and bandgap properties are analyzed by considering the pinch-off of level surfaces. The conformal coating on such templates is found to result in incomplete filling and loss of the photonic bandgap. An attempt to solve this problem is made by using electrophoretic deposition, which results in a nearly completely filled 3D titania structure.

    11. Amorphous Piezo- and Pyroelectric Phases of BaZrO3 and SrTiO3 (pages 1515–1517)

      D. Ehre, V. Lyahovitskaya, A. Tagantsev and I. Lubomirsky

      Article first published online: 9 MAY 2007 | DOI: 10.1002/adma.200602149

      Thumbnail image of graphical abstract

      Pyro- and piezoelectric quasiamorphous thin films of BaZrO3and SrTiO3 are reported. This is the first instance of a polar amorphous solid being created from a compound that does not from polar crystalline polymorphs. The pyroelectric and the piezoelectric properties of the quasi-amorphous SrTiO3 are of the same order of magnitude (10–50 %) as those of the most commonly used crystalline pyro- and piezo-electric materials, such as BaTiO3, Pb(Ti,Zr)O3, and LiNbO3 (see figure).

    12. DNA-Wrapped Single Walled Carbon Nanotubes as Rigid Templates for Assembling Linear Gold Nanoparticle Arrays (pages 1518–1522)

      X. Han, Y. Li and Z. Deng

      Article first published online: 2 MAY 2007 | DOI: 10.1002/adma.200602861

      Thumbnail image of graphical abstract

      Nanotube templates assembly: Water-soluble conjugates between gold nanoparticles and DNA-wrapped single-walled carbon nanotubes (SWNTs), as shown in the figure, are constructed based on a self-assembly strategy that does not require any chemical modifications to the sidewalls of the SWNTs, which minimizes the possibility of changes to their structure and properties. The success of assembling Au nanoparticles (AuNPs) onto SWNTs paves a way for further decoration of AuNPs on SWNTs to achieve multifunctionalities.

    13. pH-Responsive Microrods Produced by Electric-Field-Induced Aggregation of Colloidal Particles (pages 1523–1527)

      D. R. E. Snoswell, R. K. Brill and B. Vincent

      Article first published online: 9 MAY 2007 | DOI: 10.1002/adma.200601824

      Thumbnail image of graphical abstract

      Poly(2-vinylpyridine) microgel particles and polystyrene latex are aggregated in an alternating electric field to produce a new class of microrods. An electric field simultaneously accelerates the aggregation of oppositely charged particles, and templates the aggregates into linear structures. Rods up to 100 μm in length can be reversibly extended by 20 % by a change in solution pH because of the swelling properties of the microgel particles (see figure).

  5. Research News

    1. Top of page
    2. Cover Picture
    3. Contents
    4. Reviews
    5. Communications
    6. Research News
    7. Index
    1. Aligned Porous Structures by Directional Freezing (pages 1529–1533)

      H. Zhang and A. I. Cooper

      Article first published online: 30 APR 2007 | DOI: 10.1002/adma.200700154

      Thumbnail image of graphical abstract

      A broad range of aligned porous materials can be formed using directional freezing techniques. This route is versatile and can be applied to aqueous solutions/suspensions, organic solutions/suspensions, and liquid CO2 solutions. The potential advantages of this method are highlighted by, for example, the production of complex 3D biaxially aligned composite structures (see figure) that would be inaccessible by lithographic routes.

  6. Index

    1. Top of page
    2. Cover Picture
    3. Contents
    4. Reviews
    5. Communications
    6. Research News
    7. Index

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