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

• hematite α-Fe2O3 (JCPDS record number 99-100-0140) can also be observed [26]. Since the surface of finely divided materials is highly reactive, partial oxidation of Fe3O4 into Fe2O3 may have taken place during the handling of the nanocrystals [28][29]. The crystallites sizes of the Mn:ZnS/ZnS/Fe3O4

• nanoparticles were calculated using the Scherrer formula based on the width of the most intense (111) diffraction peak (Table 1). Figure 3 shows transmission electron microscopy (TEM) and high-resolution TEM (HR-TEM) images of the Mn:ZnS/ZnS and Mn:ZnS/ZnS/Fe3O4 (1.5) materials. All Mn:ZnS/ZnS core/shell

Synthesis, characterization and in vitro biocompatibility study of Au/TMC/Fe₃O₄ nanocomposites as a promising, nontoxic system for biomedical applications

• Hanieh Shirazi,
• Maryam Daneshpour,
• Soheila Kashanian and
• Kobra Omidfar

Beilstein J. Nanotechnol. 2015, 6, 1677–1689, doi:10.3762/bjnano.6.170

• ) and maghemite (γ-Fe2O3). The increasing number of studies that report the successful use of Fe3O4 nanoparticles for industrial (e.g., as synthetic pigments or as catalyst), biomedical (in vivo and in vitro), environmental, and analytical applications, demonstrate their versatility. Since it is

• important that the Fe3O4 nanoparticles are stable under physiological conditions that are necessary for biomedical applications, it is crucial to use controllable synthesis conditions in order to obtain monodisperse, uniform nanoparticles with desired properties [18]. Despite their low toxicity, fine

• that these polymers provide an adsorbent network on the surface of the Fe3O4 nanoparticles, it was decided to additionally assemble Au nanoparticles onto the polymer-coated magnetic particles, resulting in the development of novel nanocomposites. The final diameter of the resulting nanocomposite was

Comparative evaluation of the impact on endothelial cells induced by different nanoparticle structures and functionalization

• Lisa Landgraf,
• Ines Müller,
• Peter Ernst,
• Miriam Schäfer,
• Christina Rosman,
• Isabel Schick,
• Oskar Köhler,
• Hartmut Oehring,
• Vladimir V. Breus,
• Thomas Basché,
• Carsten Sönnichsen,
• Wolfgang Tremel and
• Ingrid Hilger

Beilstein J. Nanotechnol. 2015, 6, 300–312, doi:10.3762/bjnano.6.28

• of all variants (Au@Fe3O4, Au-NH2@Fe3O4, Fe3O4 and Au) in endosomes and a final deposition in lysosomes (Figure 5b). The good biocompatibility of the bare Au@Fe3O4 and Fe3O4 nanoparticles can be explained by the presence of small and clear delineated endosomes and secondary lysosomes (Figure 5b

• nanoparticles by macrophages after the treatment with genistein [56]. Interestingly, the application of chlorpromazine, selectively affecting clathrin-mediated endocytosis [57][58], led to an increased accumulation of Au@ Fe3O4 and Fe3O4 nanoparticles in HMEC-1 (Figure 6a and Figure 6c). After incubation of

• ) SVEC4-10 were treated with 30 µg/mL of gold nanoparticles functionalized with OCH3, COOH or NH2. (b) HMEC-1 cells were treated with 20 µg/mL of MnO and Au@MnO nanoparticles. (c) HMEC-1 cells were treated with 20 µg/mL of Fe3O4 and Au@Fe3O4 nanoparticles. Data were normalized to control values (no

Inorganic Janus particles for biomedical applications

• Isabel Schick,
• Steffen Lorenz,
• Dominik Gehrig,
• Stefan Tenzer,
• Wiebke Storck,
• Karl Fischer,
• Dennis Strand,
• Frédéric Laquai and
• Wolfgang Tremel

Beilstein J. Nanotechnol. 2014, 5, 2346–2362, doi:10.3762/bjnano.5.244

• particles used for catalysis [52][63][64], drug delivery [65], bimodal bioimaging [36][66][67][68], and biomedical applications [69][70] such as cancer treatment [71] are dumbbell-like Au@Fe3O4 nanoparticles. As no ternary Au-Fe-O phase or a gold oxide is present under the experimental conditions, there is

• binding of apolipoproteins and serum albumin to hydrophobic nanoparticles by Cedervall and co-workers [115]. Interestingly, there is a significant and unexpected difference in the composition of the protein corona of isotropic silica encapsulated MnO and Fe3O4 nanoparticles. By studying the protein

• of Chemistry. a) UV–vis spectra of Au@Fe3O4 nanoparticles corresponding to schematic representations in b). The scheme illustrates the shape evolution of the particles during heating (Au: dark gray, Fe3O4: bright gray). Reproduced with permission from [72]. Copyright 2008 WILEY-VCH. TEM bright field

Carbon dioxide hydrogenation to aromatic hydrocarbons by using an iron/iron oxide nanocatalyst

• Hongwang Wang,
• Jim Hodgson,
• Tej B. Shrestha,
• Prem S. Thapa,
• David Moore,
• Xiaorong Wu,
• Myles Ikenberry,
• Deryl L. Troyer,
• Donghai Wang,
• Keith L. Hohn and
• Stefan H. Bossmann

Beilstein J. Nanotechnol. 2014, 5, 760–769, doi:10.3762/bjnano.5.88

• ) employing Fe/Fe3O4 nanoparticles as catalyst. The synthesis of the catalyst and the mechanism of CO2-hydrogenation will be discussed, as well as further applications of Fe/Fe3O4 nanoparticles in catalysis. Keywords: aromatic hydrocarbons; carbon dioxide reduction; heterogenous catalysis; iron/iron oxide

• oxygen reduction reaction [46][47][48] have been reported. Synthesis of Fe/Fe3O4 nanoparticles Here we report the selective formation of aromatic hydrocarbons from CO2 hydrogenation reactions catalyzed by an Fe/Fe3O4 nanocatalyst. Recently, Sun’s group reported a facile method for synthesizing highly

• crystalline Fe/Fe3O4 nanoparticles [49]. These nanoparticles were found to be robust against deep oxidation because of the formation of a protective crystalline Fe3O4 shell upon the direct oxidation of the bcc-Fe core. The synthesis of the Fe/Fe3O4 nanoparticles was slightly modified and scaled up by a factor

A facile synthesis of a carbon-encapsulated Fe₃O₄ nanocomposite and its performance as anode in lithium-ion batteries

• Raju Prakash,
• Katharina Fanselau,
• Shuhua Ren,
• Tapan Kumar Mandal,
• Christian Kübel,
• Horst Hahn and
• Maximilian Fichtner

Beilstein J. Nanotechnol. 2013, 4, 699–704, doi:10.3762/bjnano.4.79

• or surfactants. The structure and morphology of the nanocomposite was investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Brunauer–Emmett–Teller analysis and Raman spectroscopy. Fe3O4 nanoparticles are dispersed intimately in a carbon framework. The

• carbon encapsulated Fe3O4 nanocomposite [Fe3O4–C] by employing Fe(CO)5 precursor without any templates, solvents, or surfactants. This raw material acts not only as the source of iron and oxygen, but also of carbon, which gives rise to typical nanostructures. Fe3O4 nanoparticles are dispersed intimately

• ) → Fe(s) + 5CO(g)} [16]. Subsequently, CO reacts with the active Fe nanoparticles to yield Fe3O4 nanoparticles and carbon {Fe(s) + CO(g) → Fe3O4–Cx(s) + gaseous material}. The iron nanoparticles catalyze the formation of nanotubes and shells from the in-situ generated carbon. Meanwhile, the Fe3O4

Magnetic-Fe/Fe₃O₄-nanoparticle-bound SN38 as carboxylesterase-cleavable prodrug for the delivery to tumors within monocytes/macrophages

• Hongwang Wang,
• Tej B. Shrestha,
• Matthew T. Basel,
• Raj K. Dani,
• Gwi-Moon Seo,
• Sivasai Balivada,
• Marla M. Pyle,
• Heidy Prock,
• Olga B. Koper,
• Prem S. Thapa,
• David Moore,
• Ping Li,
• Viktor Chikan,
• Deryl L. Troyer and
• Stefan H. Bossmann

Beilstein J. Nanotechnol. 2012, 3, 444–455, doi:10.3762/bjnano.3.51

• and by activating the immune system. Keywords: cell-based delivery; chemotherapeutic prodrug; magnetic Fe/Fe3O4 nanoparticles; SN38; Introduction Irinotecan (CPT-11) is a potent chemotherapeutic prodrug against various types of cancer, such as colorectal, lung, and ovarian cancer [1][2][3][4][5]. It

• highly crystalline iron(0) nanoparticles. When these nanoparticles were exposed to air at room temperature, a thin layer of Fe3O4 formed due to the oxidation of the nanoparticle surface, thus, core/shell Fe/Fe3O4 nanoparticles were constructed. The introduction of the Fe3O4 shell provides easy surface

• functionalization of the core/shell Fe/Fe3O4 nanoparticles. The obtained nanoparticles were washed with hexane and ethanol, collected by centrifugation, and dried under high vacuum for further use in this study. Synthesis of a hydrophilic dopamine-anchored InCE-cleavable linker between SN38 and Fe/Fe3O4 magnetic

Uniform excitations in magnetic nanoparticles

• Steen Mørup,
• Cathrine Frandsen and
• Mikkel Fougt Hansen

Beilstein J. Nanotechnol. 2010, 1, 48–54, doi:10.3762/bjnano.1.6

• Equation 1, and the latter approximation is valid at low temperatures. The linear temperature dependence of the magnetization in nanoparticles was first observed by Mössbauer spectroscopy studies of magnetite (Fe3O4) nanoparticles [3], but it has later been studied in nanoparticles of several other

• the relaxation is fast compared to the timescale of Mössbauer spectroscopy, and the observed magnetic hyperfine field is then given by where B0 is the saturation hyperfine field. Figure 3 shows the temperature dependence of the magnetic hyperfine field of three samples of magnetite (Fe3O4

• ) nanoparticles with different average sizes [3]. From the slopes of the fitted straight lines one can estimate the values of the magnetic anisotropy constants K. It was found that K increases with decreasing particle size. This is in accordance with the expected increase of the surface contribution to the total