Performance of colloidal CdS sensitized solar cells with ZnO nanorods/nanoparticles

• Anurag Roy,
• Partha Pratim Das,
• Mukta Tathavadekar,
• Sumita Das and
• Parukuttyamma Sujatha Devi

Beilstein J. Nanotechnol. 2017, 8, 210–221, doi:10.3762/bjnano.8.23

• analysis, as shown in Figure 3b. Further investigation of contact angle (CA) measurements by using CdS dispersions on ZnO-based films justifies the sensitization capability. The reduced CA value of 19.6° for the film fabricated with ZnO-P further ascertains its better CdS affinity whereas a moderate CA

Tunable plasmons in regular planar arrays of graphene nanoribbons with armchair and zigzag-shaped edges

• Cristian Vacacela Gomez,
• Michele Pisarra,
• Mario Gravina and
• Antonello Sindona

Beilstein J. Nanotechnol. 2017, 8, 172–182, doi:10.3762/bjnano.8.18

• ) exhibit markedly discontinuous dispersions, being split into more branches [31]. This is a consequence of the narrow widths of the two systems that generate several, distinct one-dimensional bands of π- and σ-character (Figure 1c,d). By increasing the GNR width (w > 1 nm), the number of bands increases

• , and less disjoint plasmon dispersions appear, which clearly tend to the continuous patterns of graphene (w→∞). Thus, semiconducting and semimetallic GNRs have plasmon resonances in the visible (VIS) to ultraviolet (UV) regime that may be controlled by the GNR width. This tunability feature is

• the π and π–σ plasmons of graphene. Their peak positions and dispersions are mostly influenced by the GNR width. At energies smaller than 2 eV, two more intriguing collective excitations appear, which correspond to recently reported edge and surface plasmons [26]. These modes are strongly sensitive

Streptavidin-coated gold nanoparticles: critical role of oligonucleotides on stability and fractal aggregation

• Roberta D'Agata,
• Pasquale Palladino and
• Giuseppe Spoto

Beilstein J. Nanotechnol. 2017, 8, 1–11, doi:10.3762/bjnano.8.1

• immersed in a non-adsorbing solution of double-stranded DNA [20], according to the Asakura–Oosawa model for depletion flocculation in colloidal dispersions [21][22][23][24][25]. This evidence support the hypothesis that surface deposited single or double stranded DNA, if released in solution, could cause

• suspensions [1]. Figure 2 shows the absorbance spectra of AuNP dispersions before and after the nanoparticle functionalization. Bare AuNPs exhibit a localized SPR peak at 520 nm that shifted to 524 and 528 nm upon adsorption of SA on the nanoparticle surface and subsequent conjugation with BiotinDNA

• compared to citrate-stabilized AuNPs ζ-potential (Table 1) contributes to improving the stability of functionalized nanoparticles dispersions. Nanoparticles modified with biotinylated oligonucleotides are spontaneously redispersed because of steric and electrostatic repulsion provided by the introduction

Solvent-mediated conductance increase of dodecanethiol-stabilized gold nanoparticle monolayers

• Patrick A. Reissner,
• Jean-Nicolas Tisserant,
• Antoni Sánchez-Ferrer,
• Raffaele Mezzenga and
• Andreas Stemmer

Beilstein J. Nanotechnol. 2016, 7, 2057–2064, doi:10.3762/bjnano.7.196

• nanoparticle was obtained by fitting the intensity profile of dilute dispersions (0.1 and 0.01 wt % in water) with the polydisperse spherical nanoparticle model (Supporting Information File 1, Figures S4, and S5). This allowed us to evaluate the radius of the particles either from the fitting model (r = 5.32

Intercalation and structural aspects of macroRAFT agents into MgAl layered double hydroxides

• Dessislava Kostadinova,
• Ana Cenacchi Pereira,
• Muriel Lansalot,
• Franck D’Agosto,
• Elodie Bourgeat-Lami,
• Fabrice Leroux,
• Christine Taviot-Guého,
• Sylvian Cadars and
• Vanessa Prevot

Beilstein J. Nanotechnol. 2016, 7, 2000–2012, doi:10.3762/bjnano.7.191

• ) polymerization [43] in the LDH matrix. This resulted in an exfoliated LDH/polystyrene nanocomposite with a good control of the molar mass of the polystyrene chains. Recently, we reported that highly stable dispersions at elevated macroRAFT copolymer concentrations [44] could be obtained by adsorbing statistical

A dioxaborine cyanine dye as a photoluminescence probe for sensing carbon nanotubes

• Mohammed Al Araimi,
• Petro Lutsyk,
• Anatoly Verbitsky,
• Yuri Piryatinski,
• Mykola Shandura and
• Aleksey Rozhin

Beilstein J. Nanotechnol. 2016, 7, 1991–1999, doi:10.3762/bjnano.7.190

• , 2H), 7.87 (d, J = 9 Hz, 1H), 8.13 (t, J = 12 Hz, 1H), 8.29 (t, J = 12 Hz, 1H). Preparation of SWNTs SWNTs were prepared in a similar manner as described in [12], where purified SWNTs (CoMoCAT) were used to prepare the SWNT dispersions. 1.2 mg of the SWNTs were dispersed in 20 mL of deionized (DI

• ) water in the presence of 6.5 mg sodium dodecylbenzene sulfonate (SDBS). We selected SDBS among other ionic surfactants because of its high efficiency in dispersing SWNTs [27][28]. The above dispersions were exposed to ultrasonication (NanoRuptor, Diagenode) for 1 h at 21 kHz and 250 W. Then, the

• dispersions were subjected to ultracentrifugation for 3 h at 17 °C at 45000 rpm (Beckman Coulter Optima Max-XP, MLS 50 rotor) to remove the aggregate phase and obtain the supernatant solutions of debundled SWNTs. The top 70% of the dispersion is then decanted. To prepare mixture of DOB-719, we used 20% of the

Zigzag phosphorene nanoribbons: one-dimensional resonant channels in two-dimensional atomic crystals

• Carlos. J. Páez,
• Dario. A. Bahamon,
• Ana L. C. Pereira and
• Peter. A. Schulz

Beilstein J. Nanotechnol. 2016, 7, 1983–1990, doi:10.3762/bjnano.7.189

• tailored in, are also summarized in Figure 1. The inset in Figure 1c depicts the energy window of interest, showing the top (bottom) of the valence (conduction) band and an effectively degenerate central band [11]. These central bands present cosine-like dispersions characteristic for 1D systems [11

Antitumor magnetic hyperthermia induced by RGD-functionalized Fe₃O₄ nanoparticles, in an experimental model of colorectal liver metastases

• Oihane K. Arriortua,
• Eneko Garaio,
• Borja Herrero de la Parte,
• Maite Insausti,
• Luis Lezama,
• Fernando Plazaola,
• Jose Angel García,
• Jesús M. Aizpurua,
• Maialen Sagartzazu,
• Mireia Irazola,
• Nestor Etxebarria,
• Ignacio García-Alonso,
• Alberto Saiz-López and
• José Javier Echevarria-Uraga

Beilstein J. Nanotechnol. 2016, 7, 1532–1542, doi:10.3762/bjnano.7.147

• amplitude (1–15 kA/m) at different frequencies (149, 302, 676 and 1030 kHz) for toluene dispersions of Fe3O4@OA and water dispersions of Fe3O4@PMAO and Fe3O4@PMAO_RGD. Above 600 kHz and 10 kA/m, all the dispersions present significant response, higher than 500 W/g. Taking into account that RGD

Deformation-driven catalysis of nanocrystallization in amorphous Al alloys

• Rainer J. Hebert,
• John H. Perepezko,
• Harald Rösner and
• Gerhard Wilde

Beilstein J. Nanotechnol. 2016, 7, 1428–1433, doi:10.3762/bjnano.7.134

• crystallization temperature of undeformed ribbons. Keywords: amorphous alloy; annealing; cold-rolling; nanocrystal; shear-band; Findings Crystallization reactions in metallic glasses have been extensively studied due to the beneficial effect of nanocrystal dispersions on mechanical [1][2][3][4] and magnetic

A composite structure based on reduced graphene oxide and metal oxide nanomaterials for chemical sensors

• Vardan Galstyan,
• Elisabetta Comini,
• Iskandar Kholmanov,
• Andrea Ponzoni,
• Veronica Sberveglieri,
• Nicola Poli,
• Guido Faglia and
• Giorgio Sberveglieri

Beilstein J. Nanotechnol. 2016, 7, 1421–1427, doi:10.3762/bjnano.7.133

• thermal annealing in a furnace at 400 °C as we have described in [25]. We prepared the composite material using the method described in [22]. We produced graphite oxide from natural graphite (SP-1, Bay Carbon) by means of modified Hummers method [26]. Then, we prepared aqueous dispersions of GO by

Electric field induced structural colour tuning of a silver/titanium dioxide nanoparticle one-dimensional photonic crystal

• Eduardo Aluicio-Sarduy,
• Simone Callegari,
• Diana Gisell Figueroa del Valle,
• Andrea Desii,
• Ilka Kriegel and
• Francesco Scotognella

Beilstein J. Nanotechnol. 2016, 7, 1404–1410, doi:10.3762/bjnano.7.131

• possibility to employ these photonic structures to manipulate the transmission of light. Methods Nanoparticle colloidal dispersions Silver nanoparticle dispersion was purchased by Sigma-Aldrich and was diluted in triethylene glycol monoethyl ether (Sigma-Aldrich) up a final concentration of 5 wt %. The

On the pathway of cellular uptake: new insight into the interaction between the cell membrane and very small nanoparticles

• Claudia Messerschmidt,
• Daniel Hofmann,
• Anja Kroeger,
• Katharina Landfester,
• Volker Mailänder and
• Ingo Lieberwirth

Beilstein J. Nanotechnol. 2016, 7, 1296–1311, doi:10.3762/bjnano.7.121

• dispersions was determined gravimetrically. NP dispersions for cell applications were diluted with milli-Q water to achieve the desired concentration. Dynamic light scattering (DLS) experiments were performed on an ALV instrument consisting of a goniometer and an ALV-5000 multiple-tau full-digital correlator

• dispersions at concentrations of c = 5 × 10−2 wt % were prepared by dilution of the previously described stock dispersions. All measurements were carried out at a temperature of T = 20 °C. For TEM measurements the samples were prepared by diluting the as supplied sample dispersion with water yielding a solid

Fabrication and characterization of branched carbon nanostructures

• Sharali Malik,
• Yoshihiro Nemoto,
• Hongxuan Guo,
• Katsuhiko Ariga and
• Jonathan P. Hill

Beilstein J. Nanotechnol. 2016, 7, 1260–1266, doi:10.3762/bjnano.7.116

• heated MWCNTs were then sonicated in ethanol which causes the MWCNTs to unzip and re-roll. Figure 4 shows a suggested schematic sequence in agreement with observations by Kaner et al. [35] and Geim [36] indicating that nanoribbons tend to re-roll unless prevented from doing so. Dispersions of the

• starting MWCNTs and b-MWCNTs were compared by dispersing 1 mg of each material in 4 mL of ethanol. These dispersions were then centrifuged at 3500g for 2 h and then left to stand for 24 h. The liquid suspensions are shown in Figure 5. The b-MWCNTs clearly show better dispersability compared to the starting

An ellipsometric approach towards the description of inhomogeneous polymer-based Langmuir layers

• Falko O. Rottke,
• Burkhard Schulz,
• Klaus Richau,
• Karl Kratz and
• Andreas Lendlein

Beilstein J. Nanotechnol. 2016, 7, 1156–1165, doi:10.3762/bjnano.7.107

• , e.g., thickness at the nm scale. In the present work only Δ-maps were recorded because of their high sensitivity towards thickness variations, even at ultrathin film conditions [6]. The complications and theoretical problems of estimating extremely small dispersions of Ψ for ultrathin films is known

Multiwalled carbon nanotube hybrids as MRI contrast agents

• Nikodem Kuźnik and
• Mateusz M. Tomczyk

Beilstein J. Nanotechnol. 2016, 7, 1086–1103, doi:10.3762/bjnano.7.102

• the realm of CNTs showed great potential but also the problems and imperfections that needed to be overcome. One of the first challenges was to reduce the tendency of CNTs for aggregation, which seriously affected the stability of their aqueous and buffered dispersions. Another issue was to enhance

• transformations [18]. Surprising results of the relaxation effects both in vitro and in vivo and depending on a number of parameters, such as content of the residual catalyst, size of the CNTs or "wrapping media" (the electrolyte used to stabilize the dispersions), were also reported [18][19]. We discuss these

• functionalization of the nanotubes changed in the dispersions. This method also allowed us to quantify the stability of different hybrids, e.g., the adsorption of Fe-L3-oMWCNT#Kuźnik and Fe-L4-MWCNT#Kuźnik decreased in the characteristic UV–Vis maximum by factors of 0.0097/h and 0.0147/h, respectively, over the 24

Assembling semiconducting molecules by covalent attachment to a lamellar crystalline polymer substrate

• Rainhard Machatschek,
• Patrick Ortmann,
• Renate Reiter,
• Stefan Mecking and
• Günter Reiter

Beilstein J. Nanotechnol. 2016, 7, 784–798, doi:10.3762/bjnano.7.70

• semiconducting molecules. Results Nanocrystal analysis by AFM The model of an ideal CPE45 nanocrystal Nanocrystal dispersions were prepared via nanoprecipitation with the impact of shear forces generated by ultrasonication. By cryo-transmission electron microscopy (TEM) studies on the dispersions, a thickness of

• generated by injection of a hot THF solution of CPE45 into a solution of caesiumhydroxide at pH 12 and ultrasonicated for 10 min. The dispersion (initial polymer concentration ca. 1 mg/mL) was filtered through a syringe filter. The dispersions were annealed for five hours at 90 °C and cooled to room

• temperature over a period of one hour. The resulting nanocrystal dispersions were dialyzed for 30 min against an aqueous solution of potassium hydroxide at pH 11. Experiments with polyethylene surfaces decorated by carboxyl groups have shown that at least pH 11 is needed for complete ionization of the

Magnetic switching of nanoscale antidot lattices

• Ulf Wiedwald,
• Joachim Gräfe,
• Kristof M. Lebecki,
• Maxim Skripnik,
• Felix Haering,
• Gisela Schütz,
• Paul Ziemann,
• Eberhard Goering and
• Ulrich Nowak

Beilstein J. Nanotechnol. 2016, 7, 733–750, doi:10.3762/bjnano.7.65

Antibacterial activity of silver nanoparticles obtained by pulsed laser ablation in pure water and in chloride solution

• Brunella Perito,
• Emilia Giorgetti,
• Paolo Marsili and
• Maurizio Muniz-Miranda

Beilstein J. Nanotechnol. 2016, 7, 465–473, doi:10.3762/bjnano.7.40

• larger NPs (diameter 6.1 nm; σ− = 3.1 nm; σ+ = 6.4 nm) were statistically more prominent than smaller NPs (diameter 0.9 nm; σ− = 0.5 nm; σ+ = 1.2 nm), as reported in Figure 3b. Bacterial susceptibility to AgNPs The four Ag colloidal dispersions, as obtained from laser ablation, were used for the

• found with the MBC values, where the lowest values were obtained on both microorganisms with ps-ablated AgNPs in LiCl solution. In general, all of the colloids tested were more effective than the antibiotic tested as a reference (Table 2). After storing the AgNPs colloidal dispersions for about two

Efficiency improvement in the cantilever photothermal excitation method using a photothermal conversion layer

• Natsumi Inada,
• Hitoshi Asakawa,
• Taiki Kobayashi and
• Takeshi Fukuma

Beilstein J. Nanotechnol. 2016, 7, 409–417, doi:10.3762/bjnano.7.36

• reducing the graphite concentration in the dispersions. Coarse regulation of the excitation efficiency was possible by this method. However, fine regulation only by controlling the graphite concentration was difficult due to the difference in drop volumes formed by two glass probes and the inhomogeneity of

• colloidal graphite flakes in the dispersions. Owing to these reasons, it is difficult to estimate the accurate excitation efficiency only from the graphite concentration. To solve this problem, we found the relationship between the blackened area evaluated by optical microscopy and excitation efficiency. We

• process. The colloidal graphite concentration of the dispersions used in this study are shown in the caption of Figure 5. Sonication of the coating solution was performed before the coating process. The average diameter of colloidal particles in the coating solution was measured by the dynamic light

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

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

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

• nanoplatform dispersion (3.0 mg in 3.0 mL of PBS, see above) and 30 µL of each of the proteases at every concentration level in PBS. The dispersions were incubated at 25 °C for 60 min, followed by the recording of a fluorescence spectrum at 25 °C using a Fluoromax2 spectrometer (λem = 421 nm, λex = 620–680 nm

• the proteases at every concentration level in PBS. The dispersions were incubated at 25 °C for 60 min, followed by the recording of a fluorescence spectrum at 25 °C using a Fluoromax2 spectrometer (λex = 421 nm, λem= 620–680 nm). Inactivation of serum was achieved by heating to 56 °C in an incubator

Surface coating affects behavior of metallic nanoparticles in a biological environment

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

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

• fluids [19][20][21][22][23][24][25][26][27]. NP agglomeration is intended in some applications, such as in immunoassays [28], while many others require stable colloidal dispersions of NPs at high physiological ionic strength [29]. Stabilization of metallic NPs at high electrolyte content, i.e., in

• CITAgNPs, PVPAgNPs and BSAAgNPs, the results clearly showed good colloidal stability, i.e., the size distributions in BM were similar to those obtained for dispersions in UW (Table 1). However, the absolute value of the ζ-potential for BSAAgNPs increased after dispersion in BM. Conversely, the ζ-potential

• BMP, as this protein is just slightly negatively charged at physiological pH values. The measured ζ-potentials were very close to the values determined for pure BSA dispersions, −7.5 ± 0.04 mV, which is not surprising taking into account the relatively high protein concentration. Thus, BSA conjugates

Characterisation of thin films of graphene–surfactant composites produced through a novel semi-automated method

• Nik J. Walch,
• Alexei Nabok,
• Frank Davis and
• Séamus P. J. Higson

Beilstein J. Nanotechnol. 2016, 7, 209–219, doi:10.3762/bjnano.7.19

• , and 3 indicate the number of PAH/graphene bilayers deposited. It can be seen from the data that all Ψ spectra almost coincide with each other, while the Δ spectra shift downwards upon deposition of bilayers of PAH/graphene(−)SDS. The thickness values (d) and dispersions, e.g., spectra of refractive

• thickness of the graphene–surfactant composite layer. While the dispersions of refractive index and extinction coefficient were modelled by a single Lorentzian peak lying in the IR region, the absorption peak of graphene at approximately 260 nm was outside the spectral range (370–1000 nm) of the

Controlled graphene oxide assembly on silver nanocube monolayers for SERS detection: dependence on nanocube packing procedure

• Martina Banchelli,
• Bruno Tiribilli,
• Roberto Pini,
• Luigi Dei,
• Paolo Matteini and
• Gabriella Caminati

Beilstein J. Nanotechnol. 2016, 7, 9–21, doi:10.3762/bjnano.7.2

• Figure 1b. AgNC dispersion exhibits a sharp peak around 450 nm that, according to previous reports [41][42], can be ascribed to the LSPR of nanocubes with 50 nm edge size in agreement with our TEM results and our preliminary findings [21] on different nanocube dispersions. Two minor peaks (348 and 380 nm

• a different approach overlaying GO sheets on prepacked AgNC layers in the search for a reliable method that allows conjugation of AgNPs with desired morphologies (densities, sizes and shapes) with graphene oxide continuous covering. GO forms stable colloidal dispersions in water thanks to the

pH-Triggered release from surface-modified poly(lactic-co-glycolic acid) nanoparticles

• Manuel Häuser,
• Klaus Langer and
• Monika Schönhoff

Beilstein J. Nanotechnol. 2015, 6, 2504–2512, doi:10.3762/bjnano.6.260

• particle dispersions were titrated with hydrochloric acid (25 mM). By plotting the zeta potential versus pH, the isoelectric point (IEP) can easily be determined. The IEP corresponds to a state of charge neutrality, where ζ is zero. Thus, it is an important parameter characterizing the pH region, in which

• . Therefore, PDADMAC solutions, as well as the PLGA-PEI-PAA nanoparticle dispersions, have been adjusted to pH 5, pH 7, and pH 9, respectively. After adsorption and subsequent washing, nanoparticles are characterized by the hydrodynamic radius and the zeta potential, as determined at pH 6. The dependence of

• prepared nanoparticle dispersions were adjusted to pH values between pH 7.4 and pH 0.9 before acquisition of 1H NMR spectra. As a first step, PLGA-PEI(pH 10)-PAA(pH 5)-PDADMAC(pH 9)-PAA(pH 5) nanoparticles were investigated. Alternatively, PLGA-PEI(pH 10)-PAA(pH 5)-PDADMAC(pH 9) nanoparticles have been

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

• centrifugation (three times). The precipitate was finally dispersed in hexane (5–10 mL) by sonication (ultrasonic bath, 1 h, RT). The obtained NC dispersions are stable for several months. Several variants of this procedure were carried out by changing: the manganese precursor (manganese distearate (MnSt2) or