Surface-enhanced Raman scattering by colloidal CdSe nanocrystal submonolayers fabricated by the Langmuir–Blodgett technique

• Alexander G. Milekhin,
• Larisa L. Sveshnikova,
• Tatyana A. Duda,
• Ekaterina E. Rodyakina,
• Volodymyr M. Dzhagan,
• Ovidiu D. Gordan,
• Sergey L. Veber,
• Cameliu Himcinschi,
• Alexander V. Latyshev and
• Dietrich R. T. Zahn

Beilstein J. Nanotechnol. 2015, 6, 2388–2395, doi:10.3762/bjnano.6.245

• 10.3762/bjnano.6.245 Abstract We present the results of an investigation of surface-enhanced Raman scattering (SERS) by optical phonons in colloidal CdSe nanocrystals (NCs) homogeneously deposited on both arrays of Au nanoclusters and Au dimers using the Langmuir–Blodgett technique. The coverage of the

• deposited NCs was less than one monolayer, as determined by transmission and scanning electron microscopy. SERS by optical phonons in CdSe nanocrystals showed a significant enhancement that depends resonantly on the Au nanocluster and dimer size, and thus on the localized surface plasmon resonance (LSPR

• ) energy. The deposition of CdSe nanocrystals on the Au dimer nanocluster arrays enabled us to study the polarization dependence of SERS. The maximal SERS signal was observed for light polarization parallel to the dimer axis. The polarization ratio of the SERS signal parallel and perpendicular to the dimer

Green and energy-efficient methods for the production of metallic nanoparticles

• Mitra Naghdi,
• Mehrdad Taheran,
• Satinder K. Brar,
• M. Verma,
• R. Y. Surampalli and
• J. R. Valero

Beilstein J. Nanotechnol. 2015, 6, 2354–2376, doi:10.3762/bjnano.6.243

• , surface-enhanced Raman scattering (SERS) detection and catalysis of chemical reactions. Furthermore, biocompatible and functionalized NPs have applications in diagnosis and treatment of cancer. For these two purposes, fluorescent and magnetic nanocrystals for detection of tumors and also nanosystems for

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

• Ricerche, via C. Golgi 19, 20133 Milano, Italy 10.3762/bjnano.6.238 Abstract We investigated how the outcome of the solvothermal synthesis of manganese(II) sulfide (MnS) nanocrystals (NCs) is affected by the type and amount of long chain surfactant present in the reaction mixture. Prompted by a previous

• the NC polymorphism. We found that MnS polymorphism can be controlled by appropriate selection of the surfactant. γ-MnS nanocrystals formed when a 1:2 mixture of long chain carboxylic acid and amine was used, irrespective of the presence of carboxylic acid as a free surfactant or ligand in the metal

• precursor. When we used a single surfactant (carboxylic acid, alcohol, thiol, amine), α-MnS nanocrystals were obtained. The peculiar role of the amine seems to be related to its basicity. The nanocrystals were characterized by TEM and electron diffraction; ATR-FTIR spectroscopy provided information about

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

• diffraction (XRD) to determine morphology, size, polydispersity, crystal structure and elemental composition of the nanocrystals. TEM microscopy revealed that the morphology of the nanoparticles could be fine-tuned by modifying of the synthetic conditions. A cubic-to-hexagonal phase transition of the NaYF4

• energy dispersive spectroscopy (EDX) were used to determine the morphology, crystal structure and elemental composition of the nanocrystals, respectively. All TEM micrographs, diffractograms and spectra were taken at an accelerating voltage of 120 kV. Particle size distribution was analyzed with the

• number-average diameter (TEM) and the hydrodynamic diameter (DLS) is due to the fact that hydrophobic particles tend to aggregate and cannot be resolved as individual particles by DLS. Morphology and crystalline structure of the dry OM–NaYF4:Yb3+/Er3+ nanocrystals were determined by TEM/BF, TEM/ED and

A single-source precursor route to anisotropic halogen-doped zinc oxide particles as a promising candidate for new transparent conducting oxide materials

• Daniela Lehr,
• Markus R. Wagner,
• Johanna Flock,
• Julian S. Reparaz,
• Clivia M. Sotomayor Torres,
• Alexander Klaiber,
• Thomas Dekorsy and
• Sebastian Polarz

Beilstein J. Nanotechnol. 2015, 6, 2161–2172, doi:10.3762/bjnano.6.222

• have an anisotropic, elongated shape. In contrast, the particles of the pure ZnO material are not elongated (see Figure S5, Supporting Information File 1). High-resolution (HR) TEM measurements show the high crystallinity of the single Cl@ZnO nanocrystals (see also Figure S4, Supporting Information

Mapping bound plasmon propagation on a nanoscale stripe waveguide using quantum dots: influence of spacer layer thickness

• Chamanei S. Perera,
• Alison M. Funston,
• Han-Hao Cheng and
• Kristy C. Vernon

Beilstein J. Nanotechnol. 2015, 6, 2046–2051, doi:10.3762/bjnano.6.208

• an emission wavelength of 655 nm were obtained from invitrogen (Cat. No: Q21321MP). These carboxyl QDs are made from CdSe nanocrystals shelled with a ZnS layer. The core–shell material is further coated with a polymer layer to allow for better dispersion of the QDs in aqueous solution. These QDs have

Paramagnetism of cobalt-doped ZnO nanoparticles obtained by microwave solvothermal synthesis

• Jacek Wojnarowicz,
• Sylwia Kusnieruk,
• Tadeusz Chudoba,
• Stanislaw Gierlotka,
• Witold Lojkowski,
• Wojciech Knoff,
• Malgorzata I. Lukasiewicz,
• Bartlomiej S. Witkowski,
• Anna Wolska,
• Marcin T. Klepka,
• Tomasz Story and
• Marek Godlewski

Beilstein J. Nanotechnol. 2015, 6, 1957–1969, doi:10.3762/bjnano.6.200

• , interesting perspectives in many application areas [1][2][3]. The most challenging issue nowadays is how to produce such advanced nanocrystals with well-defined and reproducible electronic, optoelectronic and magnetic properties at low cost. In the present work we investigate zinc oxide (ZnO), which is an

Correction: Formation of pure Cu nanocrystals upon post-growth annealing of Cu–C material obtained from focused electron beam induced deposition: comparison of different methods

• Aleksandra Szkudlarek,
• Alfredo Rodrigues Vaz,
• Yucheng Zhang,
• Andrzej Rudkowski,
• Czesław Kapusta,
• Rolf Erni,
• Stanislav Moshkalev and
• Ivo Utke

Beilstein J. Nanotechnol. 2015, 6, 1935–1936, doi:10.3762/bjnano.6.196

• nanocrystals; focused electron beam induced deposition (FEBID); post-growth annealing of Cu–C material; In Figure 8 of the original article, the scale of the ordinate was wrong. The correct figure looks as follows: Figure 8 in the original article: Calculated resistivity from the resistance measurement of a

Nonlinear optical properties of near-infrared region Ag₂S quantum dots pumped by nanosecond laser pulses

• Li-wei Liu,
• Si-yi Hu,
• Yin-ping Dou,
• Tian-hang Liu,
• Jing-quan Lin and
• Yue Wang

Beilstein J. Nanotechnol. 2015, 6, 1781–1787, doi:10.3762/bjnano.6.182

• superior optical limiting. We discuss the physical mechanisms responsible for the nonlinear optical response of the QDs. The average size of the nanocrystals was 5.5 nm. Our results suggest the possibility of using these Ag2S QDs for photoelectric, biosensor, optical ranging, and self-adaptive technologies

• properties of semiconductor nanocrystals [20][21][22]. Ag2S QDs have a wide range of applications in optical and other research fields. The development of their synthesis method may facilitate their application in optoelectronic devices for light absorption, photoconductor cells, IR detectors and so on [21

• this study and explained on the basis of the nonlinear optics theory of nanoparticles. Results and Discussion Figure 1 shows the analysis of a sample of Ag2S nanocrystals dispersed in chloroform (CHCl3). The QDs were synthesized using the typical procedure published previously [20]. The sizes of the

A facile method for the preparation of bifunctional Mn:ZnS/ZnS/Fe₃O₄ magnetic and fluorescent nanocrystals

• Houcine Labiadh,
• Tahar Ben Chaabane,
• Romain Sibille,
• Lavinia Balan and
• Raphaël Schneider

Beilstein J. Nanotechnol. 2015, 6, 1743–1751, doi:10.3762/bjnano.6.178

• , 54001 Nancy Cedex, France 10.3762/bjnano.6.178 Abstract Bifunctional magnetic and fluorescent core/shell/shell Mn:ZnS/ZnS/Fe3O4 nanocrystals were synthesized in a basic aqueous solution using 3-mercaptopropionic acid (MPA) as a capping ligand. The structural and optical properties of the

• properties of the composites. Nevertheless, a good compromise was achieved in order to maintain the dual modality of the nanocrystals, which may be promising candidates for various biological applications. Keywords: aqueous synthesis; bifunctional nanocrystals; magnetite; Mn-doped ZnS; quantum dots

• ; Introduction Semiconductor nanocrystals with a diameter of approximately 1–10 nm, also referred to as quantum dots (QDs), have attracted great attention due to their unique optical and electronic properties, which are not observed in bulk semiconductor materials [1][2][3]. Compared to conventional organic dyes

Atomic scale interface design and characterisation

• Carla Bittencourt,
• Chris Ewels and
• Arkady V. Krasheninnikov

Beilstein J. Nanotechnol. 2015, 6, 1708–1711, doi:10.3762/bjnano.6.174

• expanding range of applications for related nanomaterials such as boron nitride nanotubes [22] and silicon and germanium nanocrystals [23]. Recent developments in X-rays collimation optics triggered the interest in synchrotron radiation-based techniques for the study of nanostructures. In this context, X

Formation of pure Cu nanocrystals upon post-growth annealing of Cu–C material obtained from focused electron beam induced deposition: comparison of different methods

• Aleksandra Szkudlarek,
• Alfredo Rodrigues Vaz,
• Yucheng Zhang,
• Andrzej Rudkowski,
• Czesław Kapusta,
• Rolf Erni,
• Stanislav Moshkalev and
• Ivo Utke

Beilstein J. Nanotechnol. 2015, 6, 1508–1517, doi:10.3762/bjnano.6.156

• ) and (hfac)Cu(I)(DMB). Transmission electron microscopy revealed the deposition of amorphous material from Cu(II)(hfac)2. In contrast, as-deposited material from (hfac)Cu(I)(VTMS) and (hfac)Cu(I)(DMB) was nano-composite with Cu nanocrystals dispersed in a carbonaceous matrix. After annealing at around

• 150–200 °C all deposits showed the formation of pure Cu nanocrystals at the outer surface of the initial deposit due to the migration of Cu atoms from the carbonaceous matrix containing the elements carbon, oxygen, and fluorine. Post-irradiation of deposits with 200 keV electrons in a transmission

• electron microscope favored the formation of Cu nanocrystals within the carbonaceous matrix of freestanding rods and suppressed the formation on their surface. Electrical four-point measurements on FEBID lines from Cu(hfac)2 showed five orders of magnitude improvement in conductivity when being annealed

Self-assembly of nanostructures and nanomaterials

• Isabelle Berbezier and
• Maurizio De Crescenzi

Beilstein J. Nanotechnol. 2015, 6, 1397–1398, doi:10.3762/bjnano.6.144

• , nanocrystals and Q-bits. Focusing on this dynamic new field, self-assembly “the science of things that put themselves together” explores the physics of nanostructures, new synthesis approaches, in addition to size-, shape- and composition-dependent properties. The major obstacles concern the reproducibility

The Kirkendall effect and nanoscience: hollow nanospheres and nanotubes

• Abdel-Aziz El Mel,
• Ryusuke Nakamura and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2015, 6, 1348–1361, doi:10.3762/bjnano.6.139

• Co nanocrystals. They demonstrated that both the annealing temperature and the annealing time have a direct impact on the transformation kinetics of the nanoparticles from solid Co into hollow CoS. In this same study, the authors show that a similar effect occurs during oxidation or selenization of

• Co nanocrystals. Since this first report, the nanoscale Kirkendall effect has become very popular and been adopted by many research groups for the synthesis of hollow nanoparticles covering a wide range of materials including sulfides [8][26][27][28][29][30], oxides [9][10][11][30][31][32][33][34][35

• , they applied their novel approach to synthesize ZnAl2O4 nanotubes containing ZnO nanocrystals. First, rippled ZnO nanowires coated with a 12 nm thick Al2O3 layer were synthesized (Figure 13a) and then annealed at 700 °C for 5 h (Figure 13b). The annealing process results in the transformation of the

Addition of Zn during the phosphine-based synthesis of indium phospide quantum dots: doping and surface passivation

• Natalia E. Mordvinova,
• Alexander A. Vinokurov,
• Oleg I. Lebedev,
• Tatiana A. Kuznetsova and
• Sergey G. Dorofeev

Beilstein J. Nanotechnol. 2015, 6, 1237–1246, doi:10.3762/bjnano.6.127

• luminescence quantum yield through the reduction of phosphorous dangling bonds. A scenario for the growth of the colloidal InP(Zn) QDs was proposed and discussed. Keywords: core–shell nanoparticles; doped semiconductor nanocrystals; InP(Zn) quantum dots; luminescence; zinc; Introduction Colloidal quantum

• excess myristic acid is lower. Moreover, the excess myristic acid contaminates the samples and rendering them too viscous and difficult to purify. Figure 2 shows the powder XRD patterns of the InP nanocrystals with different Zn amounts added during the synthesis. The XRD pattern show a clear zinc blende

• nanocrystals solution dispersed in hexane was mixed with THF and a certain amount of myristic acid was added. The mixture was loaded into a perfluoroethylene vessel and a certain amount of etching mixture (HF in THF 1:10) was added under stirring. Characterization The UV–vis absorption spectra were measured at

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

• , France CEA/IRAMIS, CEA Saclay, 91191, Gif-sur-Yvette, France 10.3762/bjnano.6.126 Abstract Background: Highly ordered three-dimensional colloidal crystals (supracrystals) comprised of 7.4 nm diameter Au nanocrystals (with a 5% size dispersion) have been imaged and analysed using a combination of

• tunnelling microscopy and spectroscopy. Keywords: dynamic force microscopy; nanoparticle; non-contact atomic force microscopy; point contact imaging; scanning probe microscopy; supracrystal; Introduction Artificial solids comprising extended assemblies of nanocrystals with a narrow size distribution

• polyhedral supracrystals arising from precipitation in the colloidal suspension. There is a significant body of work that focuses on elucidating the electronic properties of nanocrystals and their associated 1D, 2D, and 3D assemblies. Building on the conceptual and theoretical framework put forward by

The convenient preparation of stable aryl-coated zerovalent iron nanoparticles

• Olga A. Guselnikova,
• Andrey I. Galanov,
• Anton K. Gutakovskii and
• Pavel S. Postnikov

Beilstein J. Nanotechnol. 2015, 6, 1192–1198, doi:10.3762/bjnano.6.121

• ). In the darkfield image, the nanocrystals are indicated by bright areas. In the high-resolution transmission electron microscopy (HRTEM) image, the atomic planes of the iron crystal lattice are clearly visualized. The NPs are mostly uniform in size with an average core particle diameter of 21 nm with

Tattoo ink nanoparticles in skin tissue and fibroblasts

• Colin A. Grant,
• Peter C. Twigg,
• Richard Baker and
• Desmond J. Tobin

Beilstein J. Nanotechnol. 2015, 6, 1183–1191, doi:10.3762/bjnano.6.120

• quantum dots and nanocrystals to target specific tumour antigens [6]. Other medical research on nanoparticles includes the formation of a network of nanoparticles with an insulin core that can regulate and control normal blood sugar level [7]. However, despite considerable progress in nanoscience, it is

Electronic interaction in composites of a conjugated polymer and carbon nanotubes: first-principles calculation and photophysical approaches

• Florian Massuyeau,
• Jany Wéry,
• Jean-Luc Duvail,
• Serge Lefrant,
• Abu Yaya,
• Chris Ewels and
• Eric Faulques

Beilstein J. Nanotechnol. 2015, 6, 1138–1144, doi:10.3762/bjnano.6.115

• molecules, and semiconducting nanocrystals have been extensively studied, in order to understand the photophysical changes observed on varying the particles concentration [8][9][10][11]. Notably, polymer-composite materials with different electron affinity have been used to enhance charge separation upon

From lithium to sodium: cell chemistry of room temperature sodium–air and sodium–sulfur batteries

• Philipp Adelhelm,
• Pascal Hartmann,
• Conrad L. Bender,
• Martin Busche,
• Christine Eufinger and
• Juergen Janek

Beilstein J. Nanotechnol. 2015, 6, 1016–1055, doi:10.3762/bjnano.6.105

• the functionality and the necessity of heterogeneous catalysts in Li/O2 cells remain unsolved, the search for improved heterogeneous catalysts for improved cyclability is still the subject of many new articles on Li/O2 batteries. The most promising catalyst material, ruthenium nanocrystals, was

Observing the morphology of single-layered embedded silicon nanocrystals by using temperature-stable TEM membranes

• Sebastian Gutsch,
• Daniel Hiller,
• Jan Laube,
• Margit Zacharias and
• Christian Kübel

Beilstein J. Nanotechnol. 2015, 6, 964–970, doi:10.3762/bjnano.6.99

• -von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany 10.3762/bjnano.6.99 Abstract We use high-temperature-stable silicon nitride membranes to investigate single layers of silicon nanocrystal ensembles by energy filtered transmission electron microscopy. The silicon nanocrystals are prepared

• thickness and stoichiometry are below a critical value. Keywords: electron irradiation damage; energy-filtered transmission electron microscopy; membrane; plane view; silicon nanocrystals; size control; size distribution; Introduction Si nanocrystals (Si NC) are interesting for applications in third

Nanostructuring of GeTiO amorphous films by pulsed laser irradiation

• Valentin S. Teodorescu,
• Cornel Ghica,
• Adrian V. Maraloiu,
• Mihai Vlaicu,
• Andrei Kuncser,
• Magdalena L. Ciurea,
• Ionel Stavarache,
• Ana M. Lepadatu,
• Nicu D. Scarisoreanu,
• Andreea Andrei,
• Valentin Ion and
• Maria Dinescu

Beilstein J. Nanotechnol. 2015, 6, 893–900, doi:10.3762/bjnano.6.92

• matrix was also evidenced in amorphous GeTiO films annealed in a conventional furnace [23]. The annealing at about 600 °C leads to the formation of Ge nanocrystals in the film matrix, which is formed by a crystallized mixture of two phases, the Ge in TiO2 anatase phase and the rutile phase (Ti in GeO2

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

• HRTEM investigations of the as-synthesized particles formed from the precursor solution, which yield stable zinc oxide nanoparticles (Figure 2a). TEM also indicates the successful formation of ZnO nanocrystals in solution after the completion of the microwave irradiation process. Grazing incidence X-ray

Combination of surface- and interference-enhanced Raman scattering by CuS nanocrystals on nanopatterned Au structures

• Alexander G. Milekhin,
• Nikolay A. Yeryukov,
• Larisa L. Sveshnikova,
• Tatyana A. Duda,
• Ekaterina E. Rodyakina,
• Victor A. Gridchin,
• Evgeniya S. Sheremet and
• Dietrich R. T. Zahn

Beilstein J. Nanotechnol. 2015, 6, 749–754, doi:10.3762/bjnano.6.77

• nanocrystals (NCs) with a low areal density fabricated through the Langmuir–Blodgett technology on nanopatterned Au nanocluster arrays using a combination of surface- and interference-enhanced Raman scattering (SERS and IERS, respectively). Micro-Raman spectra of one monolayer of CuS NCs deposited on a bare Si

• advantages of SERS and IERS and demonstrate stronger SERS enhancement allowing for the observation of Raman signals from CuS NCs with an ultra-low areal density. Keywords: copper sulfide (CuS) nanocrystals; interference-enhanced Raman spectroscopy; phonons; surface-enhanced Raman spectroscopy; Introduction

• Investigations of Raman scattering in nanostuctures such as nanocrystals (NCs) are limited by a low Raman cross-section because of the very low scattering volume of the nanostructures. Surface-enhanced Raman spectroscopy (SERS) taking advantage of plasmonics leads to a remarkable increase of the Raman

Low-cost formation of bulk and localized polymer-derived carbon nanodomains from polydimethylsiloxane

• Juan Carlos Castro Alcántara,
• Mariana Cerda Zorrilla,
• Lucia Cabriales,
• Luis Manuel León Rossano and
• Mathieu Hautefeuille

Beilstein J. Nanotechnol. 2015, 6, 744–748, doi:10.3762/bjnano.6.76

• processes presented shiny and dark residual materials after the polymer combustion and according to micro-Raman spectroscopy of the domains, graphitic nanocrystals and carbon nanotubes have successfully been produced by the combustion of polydimethylsiloxane layers. The fabrication processes and

• characterization of the byproduct materials are reported. We demonstrate that CVD led to bulk production of graphitic nanocrystals and single-walled carbon nanotubes while direct laser ablation may be employed for the formation of localized fluorescent nanodots. In the latter case, graphitic nanodomains and multi

• nanocrystals (GNC) are composing the shiny layers, whereas dark parts consist mainly of single-walled carbon nanotubes (SWCNT) [14]. Selective laser ablation Selective and localized laser pyrolysis has also been tested to study the formation of nanodomains from PDMS in a controlled fashion, using a low-cost