Advanced atomic force microscopy techniques II

• Thilo Glatzel,
• Ricardo Garcia and
• Thomas Schimmel

Beilstein J. Nanotechnol. 2014, 5, 2326–2327, doi:10.3762/bjnano.5.241

• batteries for a comparison of their nanoscale electrical, electrochemical, and morphological properties [6] or the analysis of CdS quantum dots on TiO2 by a combination of AFM and X-ray photoelectron spectroscopy [7]. The folding and rupture of graphene on SiC analyzed by non-contact AFM and Kelvin probe

Biopolymer colloids for controlling and templating inorganic synthesis

• Laura C. Preiss,
• Katharina Landfester and
• Rafael Muñoz-Espí

Beilstein J. Nanotechnol. 2014, 5, 2129–2138, doi:10.3762/bjnano.5.222

• . [5] prepared chitosan/silica composite microspheres by mixing an aqueous solution of the biopolymer with commercial nanosized silica particles. The obtained microparticles were dried afterwards. In further examples, chitosan matrices have also been used to immobilize CdSe quantum dots [6] and γ-Fe2O3

• particles were obtained (Figure 3). Analogous to the DNA case, peptidic supports have also been used for the deposition of metals [53] and semiconductor chalcogenide quantum dots [54][55][56][57][58][59][60][61][62][63][64][65]. B2. Biopolymer particles as “supports”: In the area of preparation of hollow

Effects of surface functionalization on the adsorption of human serum albumin onto nanoparticles – a fluorescence correlation spectroscopy study

• Pauline Maffre,
• Stefan Brandholt,
• Karin Nienhaus,
• Li Shang,
• Wolfgang J. Parak and
• G. Ulrich Nienhaus

Beilstein J. Nanotechnol. 2014, 5, 2036–2047, doi:10.3762/bjnano.5.212

• Fe–Pt nanoparticles (NPs, 6 nm radius), CdSe/ZnS quantum dots (QDs, 5 nm radius) and Au and Ag nanoclusters (1–4 nm radius), which are enshrouded by various water-solubilizing surface layers exposing different chemical functional groups (carboxyl, amino and both), thereby endowing the NPs with

• four orders of magnitude. These variations can be understood in terms of specific Coulombic interactions between the proteins and the NP surfaces. Keywords: fluorescence correlation spectroscopy; human serum albumin; nanoparticles; protein corona; quantum dots; Introduction In recent years, both

Data-adaptive image-denoising for detecting and quantifying nanoparticle entry in mucosal tissues through intravital 2-photon microscopy

• Torsten Bölke,
• Lisa Krapf,
• Regina Orzekowsky-Schroeder,
• Tobias Vossmeyer,
• Jelena Dimitrijevic,
• Horst Weller,
• Anna Schüth,
• Antje Klinger,
• Gereon Hüttmann and
• Andreas Gebert

Beilstein J. Nanotechnol. 2014, 5, 2016–2025, doi:10.3762/bjnano.5.210

• microscopy (2PM); denoising; in vivo imaging; nanoparticles; signal to noise ratio (SNR); quantum dots; Introduction Imaging methods applied to detect fluorescent nanoparticles in mucosal tissues should provide high optical resolution and allow large volumes to be scanned. An important and versatile tool

• /ZnS-core/shell/shell quantum dots (QDs) used in this study were provided by the Center for Applied Nanotechnology, CAN GmbH, Germany (CANdots, Series A). These nanocrystals are originally dispersed in a nonpolar organic solvent. To allow for bioapplications they were transferred into the aqueous phase

• authors thank Dr. Jan Niehaus (CAN-GmbH, Germany) and Sören Becker (University of Hamburg, Germany) for kindly providing the quantum dots used in this study. Supported by Deutsche Forschungsgemeinschaft (GE 647/10, HU 629/4, WE 2059/8).

Carbon nano-onions (multi-layer fullerenes): chemistry and applications

• Juergen Bartelmess and
• Silvia Giordani

Beilstein J. Nanotechnol. 2014, 5, 1980–1998, doi:10.3762/bjnano.5.207

• research on carbon nanostructures. Biological and environmental applications Biological imaging: In contrast to other carbon nanomaterials such as CNTs [52] or carbon quantum dots [53], CNOs have not been widely employed in biological marking, yet. A first report was published in 2011 by Sarkar et al. by

Silicon and germanium nanocrystals: properties and characterization

• Ivana Capan,
• Alexandra Carvalho and
• José Coutinho

Beilstein J. Nanotechnol. 2014, 5, 1787–1794, doi:10.3762/bjnano.5.189

• models and the more elaborate k·p perturbation theory have been used to give insight into the quantum confinement [39], dispersion, as well as on the dependence of the electronic levels of nanocrystals and quantum dots on strain and electric fields [40]. Such results are general and have been helpful to

Controlling the optical and structural properties of ZnS–AgInS₂ nanocrystals by using a photo-induced process

• Takashi Yatsui,
• Fumihiro Morigaki and
• Tadashi Kawazoe

Beilstein J. Nanotechnol. 2014, 5, 1767–1773, doi:10.3762/bjnano.5.187

• ], quantum dots (QDs) [4], quantum wells [5], and quantum rings [6]. Kawazoe et al., have demonstrated the room-temperature operation of AND-gate and NOT-gate devices using InAs QD pairs [7]. In a nanophotonic device, near-field energy-transfer via a dipole-forbidden energy state, which is unattainable in

Experimental techniques for the characterization of carbon nanoparticles – a brief overview

• Wojciech Kempiński,
• Szymon Łoś,
• Mateusz Kempiński and
• Damian Markowski

Beilstein J. Nanotechnol. 2014, 5, 1760–1766, doi:10.3762/bjnano.5.186

• as a quantum dots matrix [35][44]. In such a matrix, where CNs are structurally connected by some mechanical linkages (carbon chains or graphene fragments [34]), there exists a system of potential barriers, similar to the those formed by a dielectric separator in granular metals. The barriers depend

Influence of surface-modified maghemite nanoparticles on in vitro survival of human stem cells

• Michal Babič,
• Daniel Horák,
• Lyubov L. Lukash,
• Tetiana A. Ruban,
• Yurii N. Kolomiets,
• Svitlana P. Shpylova and
• Oksana A. Grypych

Beilstein J. Nanotechnol. 2014, 5, 1732–1737, doi:10.3762/bjnano.5.183

• for the above mentioned purposes [9]. Monosized iron oxide nanoparticles, sometimes called ultra-small superparamagnetic iron oxide nanoparticles, play the dominant role. Quantum dots, gold and, recently, also upconversion nanoparticles are used less frequently. The main advantages of iron oxides

• (magnetite Fe3O4 or maghemite γ-Fe2O3) are their simple preparation and their magnetic properties, which are necessary for detection. Moreover, it is convenient that iron oxides are readily metabolized in the body. From this point of view, quantum dots are disqualified due to their toxicity. Like in every

Donor–acceptor graphene-based hybrid materials facilitating photo-induced electron-transfer reactions

• Anastasios Stergiou,
• Georgia Pagona and
• Nikos Tagmatarchis

Beilstein J. Nanotechnol. 2014, 5, 1580–1589, doi:10.3762/bjnano.5.170

• materials composed of graphene and photoactive components, such as porphyrins and phthalocyanines, have been prepared and evaluated regarding photo-induced charge transfer phenomena [16][17][18]. Moreover, semiconducting quantum dots such as CdS [19][20][21][22], CdSe [23][24][25][26], CdTe [27][28], ZnO

Synthesis of hydrophobic photoluminescent carbon nanodots by using L-tyrosine and citric acid through a thermal oxidation route

• Venkatesh Gude

Beilstein J. Nanotechnol. 2014, 5, 1513–1522, doi:10.3762/bjnano.5.164

• as heterogeneous graphene quantum dots (GQDs) [15]. Many research groups developed synthetic routes to obtain CNDs without using surface passivating agents, by using natural resources like candle soot [6], orange juice [7], banana juice [16], ground soybeans [17], waste paper [18], and paper ash [19

• structural defects [2][5][15][20]. Recently, Cushing et al. reported that the origin of excitation wavelength dependent emission, the continuous red shift and the broadening of bands is due to a “giant red-edge effect” of heterogeneous graphene quantum dots. The giant red-edge effect appears because the

The cell-type specific uptake of polymer-coated or micelle-embedded QDs and SPIOs does not provoke an acute pro-inflammatory response in the liver

• Markus Heine,
• Alexander Bartelt,
• Oliver T. Bruns,
• Denise Bargheer,
• Artur Giemsa,
• Barbara Freund,
• Ludger Scheja,
• Christian Waurisch,
• Alexander Eychmüller,
• Rudolph Reimer,
• Horst Weller,
• Peter Nielsen and
• Joerg Heeren

Beilstein J. Nanotechnol. 2014, 5, 1432–1440, doi:10.3762/bjnano.5.155

• .5.155 Abstract Semiconductor quantum dots (QD) and superparamagnetic iron oxide nanocrystals (SPIO) have exceptional physical properties that are well suited for biomedical applications in vitro and in vivo. For future applications, the direct injection of nanocrystals for imaging and therapy represents

• : hepatocytes; inflammation; Kupffer cells; liver sinusoidal endothelial cells; nanoparticle toxicity; nanoparticle uptake; quantum dots; superparamagnetic iron-oxide nanocrystals; Introduction The superior optical properties of QDs compared to organic dyes render them promising candidates for the demands of

Surface processes during purification of InP quantum dots

• Natalia Mordvinova,
• Pavel Emelin,
• Alexander Vinokurov,
• Sergey Dorofeev,
• Artem Abakumov and
• Tatiana Kuznetsova

Beilstein J. Nanotechnol. 2014, 5, 1220–1225, doi:10.3762/bjnano.5.135

• , B-2020 Antwerp, Belgium 10.3762/bjnano.5.135 Abstract Recently, a new simple and fast method for the synthesis of InP quantum dots by using phosphine as phosphorous precursor and myristic acid as surface stabilizer was reported. Purification after synthesis is necessary to obtain samples with good

• precursor takes place, which leads to a better surface passivation. The electrophoretic purification technique does not increase luminescence efficiency but yields very pure quantum dots in only a few minutes. Additionally, the formation of In(OH)3 during the low temperature synthesis was explained

• . Purification of quantum dots is a very significant part of postsynthetical treatment that determines the properties of the material. But this subject is not sufficiently discussed in the literature. The paper is devoted to the processes that occur at the surface of quantum dots during purification. A new

Model systems for studying cell adhesion and biomimetic actin networks

• Dorothea Brüggemann,
• Johannes P. Frohnmayer and
• Joachim P. Spatz

Beilstein J. Nanotechnol. 2014, 5, 1193–1202, doi:10.3762/bjnano.5.131

• . The successful incorporation of partly fluorescently labelled integrin αIIbβ3 into the GUVs was confirmed by confocal microscopy. Binding experiments of integrin-GUVs on surfaces and quantum dots coated with RGD ligands revealed that the incorporated integrins were biologically active. In reflection

Enhanced photocatalytic hydrogen evolution by combining water soluble graphene with cobalt salts

• Jing Wang,
• Ke Feng,
• Hui-Hui Zhang,
• Bin Chen,
• Zhi-Jun Li,
• Qing-Yuan Meng,
• Li-Ping Zhang,
• Chen-Ho Tung and
• Li-Zhu Wu

Beilstein J. Nanotechnol. 2014, 5, 1167–1174, doi:10.3762/bjnano.5.128

• artificial catalyst for photocatalytic hydrogen evolution [23], for example, was simply constructed in situ from earth-abundant cobalt salts and CdTe quantum dots. As a new carbon material with large surface area and excellent electrical properties, graphene has raised much attention since 2004 [24][25][26

Organic and inorganic–organic thin film structures by molecular layer deposition: A review

• Pia Sundberg and
• Maarit Karppinen

Beilstein J. Nanotechnol. 2014, 5, 1104–1136, doi:10.3762/bjnano.5.123

• decline [77]. Different combinations of terephthalaldehyde, 1,4-diaminobenzene and ethanedihydrazide have been used to fabricate quantum dots of varying lengths: These thin films showed promise for sensitization in photovoltaic devices [79][80]. Hybrid inorganic–organic thin films Since the first

Photocatalysis

• Rong Xu

Beilstein J. Nanotechnol. 2014, 5, 1071–1072, doi:10.3762/bjnano.5.119

• and morphological tuning, in particular for hybrid materials systems such as Ag–ZnO, VTi/MCM-41, are important toward achieving higher solar energy conversion efficiencies. In a couple of reports, materials alternative to conventional metal oxides, for example, reduced graphene oxide, graphene quantum

• dots integrated with TiO2 nanotube arrays, and carbon nitride, have been explored to construct photocatalysts with enhanced performances. On the other hand, molecular catalysts have an advantage in design flexibility and structural tunability. A contribution based on the investigation of molecular

Functionalized nanostructures for enhanced photocatalytic performance under solar light

• Liejin Guo,
• Dengwei Jing,
• Maochang Liu,
• Yubin Chen,
• Shaohua Shen,
• Jinwen Shi and
• Kai Zhang

Beilstein J. Nanotechnol. 2014, 5, 994–1004, doi:10.3762/bjnano.5.113

• high crystallinity, high surface area and unique microstructure [63]. As the crystal size of the semiconductor is close to the exciton Bohr radius, its bandgap can be enlarged with a reduced crystal size due to the quantum confinement effect. Therefore, we have synthesized Co3O4 quantum dots (3–4 nm

• Co3O4 is not negative enough to reduce H+. Compared with bulk Co3O4, Co3O4 quantum dots have a wider bandgap. Valence-band XPS spectra showed that the valance band maxima (VBM) of Co3O4 quantum dots and bulk Co3O4 are almost at the same position, implying that the enlarged bandgap of Co3O4 quantum dots

• was mainly ascribed to the conduction band minimum (CBM) upshift. Due to the negative shift of the conduction band, Co3O4 quantum dots can split pure water into O2 and H2 stoichiometrically under visible light irradiation without any cocatalyst. This is the first report to date of Co3O4 photocatalysts

Optimizing the synthesis of CdS/ZnS core/shell semiconductor nanocrystals for bioimaging applications

• Li-wei Liu,
• Si-yi Hu,
• Ying Pan,
• Jia-qi Zhang,
• Yue-shu Feng and
• Xi-he Zhang

Beilstein J. Nanotechnol. 2014, 5, 919–926, doi:10.3762/bjnano.5.105

• applications and may offer a new direction for the early detection of cancer in humans. Keywords: bioimaging; CdS/ZnS quantum dots; Pluronic F127; Introduction Over the past decade, the use of semiconductor nanocrystals or quantum dots (QDs) has developed remarkably due to their unique features. Compared to

Optical and structural characterization of oleic acid-stabilized CdTe nanocrystals for solution thin film processing

• Claudio Davet Gutiérrez-Lazos,
• Mauricio Ortega-López,
• Manuel A. Pérez-Guzmán,
• A. Mauricio Espinoza-Rivas,
• Francisco Solís-Pomar,
• Rebeca Ortega-Amaya,
• L. Gerardo Silva-Vidaurri,
• Virginia C. Castro-Peña and
• Eduardo Pérez-Tijerina

Beilstein J. Nanotechnol. 2014, 5, 881–886, doi:10.3762/bjnano.5.100

• , 350 and 400 °C. On the other hand, oleic acid is a green organic ligand, which has been successfully used in preparing a great variety of colloidal materials [15][25][26], including CdTe quantum dots [27][28][29]. This work presents our early results on the elaboration of CdTe-based inks for potential

Resonance of graphene nanoribbons doped with nitrogen and boron: a molecular dynamics study

• Ye Wei,
• Haifei Zhan,
• Kang Xia,
• Wendong Zhang,
• Shengbo Sang and
• Yuantong Gu

Beilstein J. Nanotechnol. 2014, 5, 717–725, doi:10.3762/bjnano.5.84

• synthesised through chemical functionalization with hydroxy and methyl groups or hydrogen [10], the decoration with quantum dots [11], noble metal nanoparticles (NPs) [12], or complex biomolecular structures [13][14]. A number of works have been conducted to investigate the properties of graphene derivatives

Nanostructure sensitization of transition metal oxides for visible-light photocatalysis

• Hongjun Chen and
• Lianzhou Wang

Beilstein J. Nanotechnol. 2014, 5, 696–710, doi:10.3762/bjnano.5.82

• quantum dots, plasmonic metal nanostructures, and carbon nanostructures for coupling with wide-bandgap transition metal oxides to design better visible-light active photocatalysts. The underlying mechanisms of the composite photocatalysts, e.g., the light-induced charge separation and the subsequent

• utilize solar energy for the investigation of photocatalysis. There is a large array of excellent review articles covering selected aspects of the design of photocatalysts in the past years. In this review, we focus on a variety of nanostructures including quantum dots, plasmonic metal nanostructures and

• visible light photocatalysis which is important for the photo-degradation of organic pollutants and the splitting of water for the production of H2 fuel. In this section, we mainly focus on the different nanostructures like quantum dots, plasmonic metal nanostructures, and carbon-based nanostructures used

A visible-light-driven composite photocatalyst of TiO₂ nanotube arrays and graphene quantum dots

• Donald K. L. Chan,
• Po Ling Cheung and
• Jimmy C. Yu

Beilstein J. Nanotechnol. 2014, 5, 689–695, doi:10.3762/bjnano.5.81

• incorporation of graphene quantum dots could extend the photo-response of the nanotubes to the visible-light range. Graphene quantum dot-sensitized TiO2 nanotube arrays were synthesized by covalently coupling these two materials. The product was characterized by Fourier-transform infrared spectrometry (FTIR

• light irradiation. Keywords: anodic oxidation; graphene quantum dots; photocatalyst; photodegradation; TiO2 nanotube arrays; Introduction Semiconductor-mediated photocatalysis is a promising technique for the conversion of solar energy as well as degradation of organic pollutants in air and water [1

• , graphene sheets are usually micrometer-sized and they can hardly be introduced into efficient nano-sized photocatalysts on a solid support, for example, TNAs. Zero-dimensional graphene quantum dots (GQDs) are defined as few-layered graphene with lateral dimensions smaller than 100 nm [28]. Due to quantum

Injection of ligand-free gold and silver nanoparticles into murine embryos does not impact pre-implantation development

• Ulrike Taylor,
• Wiebke Garrels,
• Annette Barchanski,
• Svea Peterson,
• Laszlo Sajti,
• Andrea Lucas-Hahn,
• Lisa Gamrad,
• Ulrich Baulain,
• Sabine Klein,
• Wilfried A. Kues,
• Stephan Barcikowski and
• Detlef Rath

Beilstein J. Nanotechnol. 2014, 5, 677–688, doi:10.3762/bjnano.5.80

• , nanoparticles were found to be stopped by the placental barrier [4][5][6]. The majority of authors, however, observed placental crossing. This encompasses studies of nanoparticles composed of gold [7][8], titanium dioxide [9][10], CdTe/CdS quantum dots [11], and polystyrene [12]. Thus, transplacental crossing

Encapsulation of nanoparticles into single-crystal ZnO nanorods and microrods

• Jinzhang Liu,
• Marco Notarianni,
• Llew Rintoul and
• Nunzio Motta

Beilstein J. Nanotechnol. 2014, 5, 485–493, doi:10.3762/bjnano.5.56

• . Thus the options for lasing wavelength and resonant mode orders are limited. There is a large variety of nanoparticles that have various luminescent properties and potential applications. Luminescent nanoparticles including semiconductor quantum dots, nanodiamonds (NDs) with nitrogen-vacancy (NV

• ) centres, and dye-doped polymer nanobeads, etc., have wide applications based on their luminescent properties. Luminescent NDs can be used for magnetic sensing [14]; dye-doped polymer nanobeads can act as laser gain media [15], depending on the selection of dye molecules. Semiconductor quantum dots can be

• interesting because they are not only optical cavities but also components for developing UV light-emitting diodes (LEDs). If luminescent quantum dots or dye-doped polymer nanobeads can be encapsulated into a ZnO nano/microrod that is integrated into a LED, the UV emission of ZnO can act as an excitation