Caveolin-1 and CDC42 mediated endocytosis of silica-coated iron oxide nanoparticles in HeLa cells

• Nils Bohmer and
• Andreas Jordan

Beilstein J. Nanotechnol. 2015, 6, 167–176, doi:10.3762/bjnano.6.16

• oxide nanoparticles (SPIONs) SPIONs were provided and characterized by MagForce AG. SPIONs with an iron oxide core of 15 nm and a silica shell of 5 nm were modified by coupling the respective functional groups as an ethoxy- or rather methoxysilane to the free hydroxy groups of the surface (Figure 2

Multifunctional layered magnetic composites

• Maria Siglreitmeier,
• Baohu Wu,
• Tina Kollmann,
• Martin Neubauer,
• Gergely Nagy,
• Dietmar Schwahn,
• Vitaliy Pipich,
• Damien Faivre,
• Dirk Zahn,
• Andreas Fery and
• Helmut Cölfen

Beilstein J. Nanotechnol. 2015, 6, 134–148, doi:10.3762/bjnano.6.13

• helical (Gly–Hyp–Pro)n peptide [44] of 100 Å length with two associated iron clusters. a) The ferric ion (light blue) is coordinated by seven oxygen atoms of which the three hydroxides show the strongest interaction and an Fe–O distance of 2.7 Å. The Fe–O distances to the solvent and to carbonyl/hydroxy

• groups of collagen were found to be about 3 Å. b) The ferrous ion (green) is also coordinated by seven oxygen atoms, but does not show a bipyramidal structure. More importantly, one of the hydroxide ions dissociated into the solvent. The Fe–O distances for iron–collagen and iron–water contacts were found

Size-dependent density of zirconia nanoparticles

• Agnieszka Opalinska,
• Iwona Malka,
• Wojciech Dzwolak,
• Tadeusz Chudoba,
• Adam Presz and
• Witold Lojkowski

Beilstein J. Nanotechnol. 2015, 6, 27–35, doi:10.3762/bjnano.6.4

• effect of the surface layer on the NP density becomes particularly evident for NPs smaller than 50 nm, and thus, the density of nanoparticles is size dependent. Keywords: density; hydrothermal synthesis; hydroxy groups; nanometrology; nanopowders; zirconia; Introduction Zirconium oxide (ZrO2) has a

• improvement in the density was attributed to the higher crystallinity of the nanoparticles, that is, a smaller amount of amorphous hydroxides were present as the synthesis temperature was increased. The presence of hydroxy groups on the nanoparticle surface may strongly influence many of their properties such

• as their chemical reactivity and hydrophilic properties. The hydroxy groups on the NP surface can also operate as effective adsorption sites for organic substances from the atmosphere [23]. Grave and colleagues attributed the increase of the nanopowder luminescence intensity with gain growth to the

Synthesis and characterization of fluorescence-labelled silica core-shell and noble metal-decorated ceria nanoparticles

• Rudolf Herrmann,
• Markus Rennhak and
• Armin Reller

Beilstein J. Nanotechnol. 2014, 5, 2413–2423, doi:10.3762/bjnano.5.251

• Figure 1 containing triethoxysilyl groups to ensure easy connections to hydroxy groups at the surface of oxidic nanoparticles (MPD: [5]; BPD: [6][7]). A similar asymmetric dye is reported in [8]. The fluorescence emission spectrum of MPD in ethanol (Figure 2, left) upon excitation at 488 nm shows an

• media not exceeding one weak of duration. At 120 °C at ceria NP the dye is completely destroyed within 90 min, the typical conditions for sterilization prior to biological experiments. Oxidic nanoparticles like SiO2, TiO2, CeO2, ZnO and Al2O3 generally contain hydroxy groups at their surface to saturate

• dangling bonds at the margin of the three-dimensional networks. These groups can react with the triethoxysilyl group of APS-modified dyes and connect them covalently to the surface. In principle, each −Si(OEt)3 group can form three M–O–Si bonds, provided that the density of the hydroxy groups at the

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

• electron donor and C60 were added to GO through an esterification reaction between the carboxyl groups of GO and the hydroxy groups present on ZnPc as well as on the fullerene derivative. Photoexcitation of ZnPc–GO–C60 at 390 nm, the wavelength at which ZnPc was predominantly excited, resulted in the

Ionic liquid-assisted formation of cellulose/calcium phosphate hybrid materials

• Ahmed Salama,
• Mike Neumann,
• Christina Günter and
• Andreas Taubert

Beilstein J. Nanotechnol. 2014, 5, 1553–1568, doi:10.3762/bjnano.5.167

• 3500 cm−1, which suggests that these precipitates are relatively free from water or hydroxy groups. In contrast, all other samples (CPGAA48, CPNaOH24, CPNaOH48) show strong bands at 3350 to 3360 cm−1 indicating the presence of significant amounts of hydroxy- or water-containing calcium phosphate phases

A sonochemical approach to the direct surface functionalization of superparamagnetic iron oxide nanoparticles with (3-aminopropyl)triethoxysilane

• Bashiru Kayode Sodipo and
• Azlan Abdul Aziz

Beilstein J. Nanotechnol. 2014, 5, 1472–1476, doi:10.3762/bjnano.5.160

• sonochemically assisted silanization process. More fundamental research needs to be carried out. In the silanization reaction, the ethoxy groups of the APTES molecule react with the terminal hydroxy groups (OH) on the SPION binding site to form silanol (Si–O–H) groups. The Si–O–H further condenses with other

Enhancement of photocatalytic H₂ evolution of eosin Y-sensitized reduced graphene oxide through a simple photoreaction

• Weiying Zhang,
• Yuexiang Li,
• Shaoqin Peng and
• Xiang Cai

Beilstein J. Nanotechnol. 2014, 5, 801–811, doi:10.3762/bjnano.5.92

• hydroxy groups are gradually removed from GO, resulting in an increase of sp2 π-conjugated domains and defect carbons with holes for the formed RGO. The RGO conductivity increases due to the restoration of sp2 π-conjugated domains. The photocatalytic activity of EY-RGO/Pt for hydrogen evolution was

• through controlling irradiation time. After the irradiation, the epoxy, carbonyl and hydroxy groups of GO are gradually removed, sp2 π-conjugated domains increase, and the formed RGO sheets have holes. The conductivity of RGOx and the adsorption amount of EY on the surface of RGOx increase with the

Photoactivation of luminescence in CdS nanocrystals

• Valentyn Smyntyna,
• Bogdan Semenenko,
• Valentyna Skobeeva and
• Nikolay Malushin

Beilstein J. Nanotechnol. 2014, 5, 355–359, doi:10.3762/bjnano.5.40

• exhibited a photostimulation of the short-wavelength luminescence with λmax = 480 nm. The determining factor of the photostimulation effect is the phenomenon of adsorption of water molecules on the surface of the nanocrystals. Hydroxy groups of the water molecules participate in the passivation of surface

Study of mesoporous CdS-quantum-dot-sensitized TiO₂ films by using X-ray photoelectron spectroscopy and AFM

• Mohamed N. Ghazzal,
• Robert Wojcieszak,
• Gijo Raj and
• Eric M. Gaigneaux

Beilstein J. Nanotechnol. 2014, 5, 68–76, doi:10.3762/bjnano.5.6

• peaks was 5.7 eV, which is consistent with the binding energy separation observed for stoichiometric TiO2 [16]. The O 1s peak was deconvoluted into three peaks at 529.8, 530.7 and 532.2 eV for all samples. These can be assigned to oxygen in the O−Ti bonds and O−H bonds of the hydroxy groups and in O−C

Structural, optical and photocatalytic properties of flower-like ZnO nanostructures prepared by a facile wet chemical method

• Sini Kuriakose,
• Neha Bhardwaj,
• Jaspal Singh,
• Biswarup Satpati and
• Satyabrata Mohapatra

Beilstein J. Nanotechnol. 2013, 4, 763–770, doi:10.3762/bjnano.4.87

• form superoxide anion radicals (•O2−) (Equation 6). The holes generated in the valence band of ZnO react with surface hydroxy groups to produce highly reactive hydroxyl (•OH) radicals (Equation 7). The photogenerated holes can lead to the production of •OH radicals through the dissociation of water

Selective surface modification of lithographic silicon oxide nanostructures by organofunctional silanes

• Thomas Baumgärtel,
• Christian von Borczyskowski and
• Harald Graaf

Beilstein J. Nanotechnol. 2013, 4, 218–226, doi:10.3762/bjnano.4.22

• . The few surface hydroxy groups also lead to a much slower binding rate of OTS to the LAO oxide. Even after several hours in the OTS solution, the surface was not fully covered with OTS, whereas for “piranha”-cleaned silica a fractional surface coverage near unity was reported within a few minutes [29

• of silane monolayers on nanoscopic silicon oxide nanostructures has proven to be much more sensitive towards ambient humidity than, e.g., silanization of larger OH-terminated silica surfaces. This is most likely due to a lower density of surface hydroxy groups, which requires a longer reaction time

Paper modified with ZnO nanorods – antimicrobial studies

• Mayuree Jaisai,
• Sunandan Baruah and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2012, 3, 684–691, doi:10.3762/bjnano.3.78

• the inhibition zone. Growth of A. niger in the presence of (a) untreated paper and (b) paper with ZnO nanorods, after 72 h of growth. Schematic diagram showing possible hydrogen bonding of the hydroxy groups on the cellulose molecule with surface oxygen atoms of the ZnO nanoparticles. Scanning

Conducting composite materials from the biopolymer kappa-carrageenan and carbon nanotubes

• Ali Aldalbahi,
• Jin Chu,
• Peter Feng and
• Marc in het Panhuis

Beilstein J. Nanotechnol. 2012, 3, 415–427, doi:10.3762/bjnano.3.48

• from various sources of the Rhodophyta (marine red algae). The carrageenans are well known for their gel-forming and thickening properties [39][40]. This biopolymer is an anionic polysaccharide whose structure contains galactose, 3,6-anhydrogalactose units, carboxy and hydroxy groups and ester sulfates

Noncontact atomic force microscopy study of the spinel MgAl₂O₄(111) surface

• Morten K. Rasmussen,
• Kristoffer Meinander,
• Flemming Besenbacher and
• Jeppe V. Lauritsen

Beilstein J. Nanotechnol. 2012, 3, 192–197, doi:10.3762/bjnano.3.21

• surface in atomic detail with NC-AFM, and such future studies may be able to clarify the role of additional O vacancies and also shed light on surface hydroxy groups (OH), which have been observed to play a role in the stabilization of the MgAl2O4(100) surface [12]. Conclusion The NC-AFM study presented