Overview about the localization of nanoparticles in tissue and cellular context by different imaging techniques

• Anja Ostrowski,
• Daniel Nordmeyer,
• Alexander Boreham,
• Cornelia Holzhausen,
• Lars Mundhenk,
• Christina Graf,
• Martina C. Meinke,
• Annika Vogt,
• Sabrina Hadam,
• Jürgen Lademann,
• Eckart Rühl,
• Ulrike Alexiev and
• Achim D. Gruber

Beilstein J. Nanotechnol. 2015, 6, 263–280, doi:10.3762/bjnano.6.25

• possibilities [15][16]. However, other authors have failed to see an aggravation of disease. In some cases, they even reported an alleviation of skin lesions following exposure with SiO2-NP or zinc oxide NP (ZnO-NP) [17][18]. ZnO-NP and titanium dioxide NP (TiO2-NP) are major ingredients of sunscreens [19] and

• various cancers [45][46][47][48]. In several applications, they have proven to possess excellent tumor-targeting efficacy [49]. Likewise, titanium dioxide nanoparticles, essential components of sunscreens, were visualized as yellow-brown particles on superficial stratum corneum layers in HE-stained skin

• example, titanium dioxide, SiO2-NP or QD, TEM has been widely used to characterize the morphology and size of NP as well as their location in tissues [28][35][39][113][156][157][158]. It has to be kept in mind, however, that artifacts due to staining with lead citrate and uranyl acetate can easily be

Interaction of dermatologically relevant nanoparticles with skin cells and skin

• Annika Vogt,
• Fiorenza Rancan,
• Sebastian Ahlberg,
• Berouz Nazemi,
• Chun Sik Choe,
• Maxim E. Darvin,
• Sabrina Hadam,
• Ulrike Blume-Peytavi,
• Kateryna Loza,
• Jörg Diendorf,
• Matthias Epple,
• Christina Graf,
• Eckart Rühl,
• Martina C. Meinke and
• Jürgen Lademann

Beilstein J. Nanotechnol. 2014, 5, 2363–2373, doi:10.3762/bjnano.5.245

• sensitive imaging and detection methods are required. Here, we present our studies on nanoparticle interactions with skin, skin cells, and biological media. Silica, titanium dioxide and silver particles were chosen as representative examples for different types of skin exposure to nanomaterials, e.g

• ., unintended environmental exposure (silica) versus intended exposure through application of sunscreen (titanium dioxide) or antiseptics (silver). Because each particle type exhibits specific physicochemical properties, we were able to apply different combinations of methods to examine skin penetration and

• as a result of interactions with the skin microenvironment. In the following, we present results obtained from own studies on the interactions of skin, skin cells and biological media with silica, titanium dioxide and silver particles as representatives for nanomaterials of high relevance from the

Towards bottom-up nanopatterning of Prussian blue analogues

• Virgile Trannoy,
• Marco Faustini,
• David Grosso,
• Sandra Mazerat,
• François Brisset,
• Alexandre Dazzi and
• Anne Bleuzen

Beilstein J. Nanotechnol. 2014, 5, 1933–1943, doi:10.3762/bjnano.5.204

• treatment, which induces the decomposition of the organic part and the crystallization of the titanium dioxide leading to the nanoperforated layer. The fourth step is the selective functionalization of the surfaces to localize the PBA growth within the perforations while avoiding its formation outside. The

• under an IR-lamp at 450 °C over 5 min, which results in the decomposition of the organic part and the crystallization of the titanium dioxide leading to the nanoperforated layer (ca. 15 nm) with homogeneous and ordered holes (50 nm in diameter) giving access to the gold layer underneath (Scheme 1) [15

A reproducible number-based sizing method for pigment-grade titanium dioxide

• Ralf Theissmann,
• Manfred Kluwig and
• Thomas Koch

Beilstein J. Nanotechnol. 2014, 5, 1815–1822, doi:10.3762/bjnano.5.192

• lacking. By using the example of titanium dioxide, this paper shows that both necessities are well met by the sophisticated counting algorithm presented here, which is based on the imaging of polished sections of embedded particles and subsequent automated image analysis. The data presented demonstrate

• that the typical difficulties of sizing processes are overcome by the proposed method of sample preparation and image analysis. In other words, a robust, reproducible and statistically reliable method is presented, which leads to a number-based size distribution of pigment-grade titanium dioxide, for

• example, and therefore allows reliable classification of this material according to forthcoming regulations. Keywords: electron microscopy; particle size; pigment; sizing; titanium dioxide; Introduction Titanium dioxide is among the ten most abundant materials on the Earth [1]. In the form of a fine

Microstructural and plasmonic modifications in Ag–TiO₂ and Au–TiO₂ nanocomposites through ion beam irradiation

• Venkata Sai Kiran Chakravadhanula,
• Yogendra Kumar Mishra,
• Venkata Girish Kotnur,
• Devesh Kumar Avasthi,
• Thomas Strunskus,
• Vladimir Zaporotchenko,
• Dietmar Fink,
• Lorenz Kienle and
• Franz Faupel

Beilstein J. Nanotechnol. 2014, 5, 1419–1431, doi:10.3762/bjnano.5.154

• deposited by the DC planar magnetron source ION’X 2UHV (Thin Film Consulting). A similar-type RF magnetron source was used for sputtering the copper-bonded titanium dioxide (Williams Advanced Materials) to prevent charging of the target. The deposition rates from both targets were in situ monitored by two

DFT study of binding and electron transfer from colorless aromatic pollutants to a TiO₂ nanocluster: Application to photocatalytic degradation under visible light irradiation

• Corneliu I. Oprea,
• Petre Panait and
• Mihai A. Gîrţu

Beilstein J. Nanotechnol. 2014, 5, 1016–1030, doi:10.3762/bjnano.5.115

• ; density functional theory; photocatalytic degradation; titanium dioxide; visible light irradiation; Introduction Titania, TiO2, has been widely used as photocatalyst for environmental applications [1][2][3][4][5][6], particularly for waste water purification. Due to its large band gap TiO2 absorbs only

• complexation of colloidal titanium dioxide [18]. This results in the formation of a six-atom ring with a chelating type of bonding to the same Ti(IV) ion. Similarly, the binding of the salicylic acid to titania was thought as bidentate chelate through the oxygen atoms of –OH and of –OCOH [14][20

Growth and characterization of CNT–TiO₂ heterostructures

• Yucheng Zhang,
• Ivo Utke,
• Johann Michler,
• Gabriele Ilari,
• Marta D. Rossell and
• Rolf Erni

Beilstein J. Nanotechnol. 2014, 5, 946–955, doi:10.3762/bjnano.5.108

• /metal oxide material systems. Keywords: atomic layer deposition (ALD); carbon nanotubes; electron energy loss spectroscopy (EELS); interface; titanium dioxide (TiO2); transmission electron microscopy (TEM); Introduction Since the discovery by Iijima in 1991, carbon nanotubes (CNTs) have always been on

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

• photosensitization of nanoporous titanium dioxide, zinc oxide, tin dioxide, niobium oxide, and tantalum oxide by quantum-sized cadmium sulfide, lead sulfide, silver sulfide, antimony sulfide, and bismuth sulfide. They found that the photocurrent quantum yields of these photosensitized transition metal oxides can be

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

• ][2]. Among various photocatalysts, nanostructured titanium dioxide (TiO2) is the most widely used because of its high activity, long-term stability and low production cost [3][4]. However, pure TiO2 is not efficient for solar-driven applications because it requires UV excitation [5]. Belonging to one

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

• ][17][18][19][20], nickel (NiNP) [21], zinc oxide (ZnONP) [22][23], titanium dioxide (TiO2NP) [23][24][25], aluminium trioxide (Al2O3NP) [23] and copper (CuNP) [22][25]. Toxic effects were observed after exposure to AgNP, CuNP, ZnONP and NiNP. AuNP, TiO2NP and Al2O3NP, on the other hand, seemed to be

• all studies regarding embryotoxicity of nanoparticles were performed in mouse pups after exposing their mothers to titanium dioxide. While no information was given concerning the impact on early embryo development, it seems noteworthy that, regardless of the exposure route, in several studies pups of

Applicability and costs of nanofiltration in combination with photocatalysis for the treatment of dye house effluents

• Wolfgang M. Samhaber and
• Minh Tan Nguyen

Beilstein J. Nanotechnol. 2014, 5, 476–484, doi:10.3762/bjnano.5.55

• generated by UV irradiation of photocatalysts in the reaction system. Commonly applied photocatalysts include TiO2, ZnO, Fe2O3, CdS, GaP and ZnS. Among these, titanium dioxide (TiO2) has attracted great interest in research and development because of its mechanical properties, chemical and thermal stability

Modeling and optimization of atomic layer deposition processes on vertically aligned carbon nanotubes

• Nuri Yazdani,
• Vipin Chawla,
• Eve Edwards,
• Vanessa Wood,
• Hyung Gyu Park and
• Ivo Utke

Beilstein J. Nanotechnol. 2014, 5, 234–244, doi:10.3762/bjnano.5.25

• , is estimated to be 1/VAB22/3, where VAB2 is the volume of a deposited oxide unit, here determined by the dimensions of the titanium dioxide unit cell. By using the parameters defined in Table 1, the concentration of the precursor as a function of the depth within the VACNT array is plotted at various

• typical ALD deposition rates for titanium dioxide. In principle, one can modify the precursor surface adsorption density to achieve more reasonable deposition rates. The two extreme limits for the maximum growth per cycle would be the limits, at which the density is either determined by the oxide volume

• multiwalled CNTs, 50–90 µm in height. By using scanning electron microscopy (SEM), the distribution of CNT diameters is measured, and the bare CNT radii are found to be 6.3 ± 0.2 nm. Titanium dioxide is deposited on the CNTs by using a custom-built ALD system. The depositions are performed at 225 °C with a

Quantum size effects in TiO₂ thin films grown by atomic layer deposition

• Massimo Tallarida,
• Chittaranjan Das and
• Dieter Schmeisser

Beilstein J. Nanotechnol. 2014, 5, 77–82, doi:10.3762/bjnano.5.7

• size effects; titanium dioxide (TiO2); water splitting; X-ray absorption spectroscopy (XAS); Introduction Titanium dioxide (TiO2) is an important material for the photoelectrolysis of water [1] and for many other photocatalytic reactions [2]. Its effective conversion of solar light, although limited

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

• at the surface of the titanium dioxide films. This result contradicts that obtained by using XPS surface analysis performed on the films, which confirmed the presence of CdS nanoparticles (Table 1, see below). The formation of CdS inside the films pores could explain the discrepancy. Consequently

• /TiO2 sample. Absorption spectra of the CdS-sensitized titanium dioxide films after different numbers of deposition cycles. XPS analysis. Spectra of Ti 2p, O 1s, C 1s, Cd 3d and S 2p, and core peaks for 15×CdS/TiO2 sample. (a) CdS particle size calculated by Davis model vs NIR (normalized intensity

Characterization of electroforming-free titanium dioxide memristors

• John Paul Strachan,
• J. Joshua Yang,
• L. A. Montoro,
• C. A. Ospina,
• A. J. Ramirez,
• A. L. D. Kilcoyne,
• Gilberto Medeiros-Ribeiro and
• R. Stanley Williams

Beilstein J. Nanotechnol. 2013, 4, 467–473, doi:10.3762/bjnano.4.55

• -970, Brazil Universidade Federal de Minas Gerais, 31270-901, Belo Horizonte, MG, Brazil Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA 10.3762/bjnano.4.55 Abstract Metal–insulator–metal (MIM) structures based on titanium dioxide have demonstrated reversible and

Kelvin probe force microscopy of nanocrystalline TiO₂ photoelectrodes

• Alex Henning,
• Gino Günzburger,
• Res Jöhr,
• Yossi Rosenwaks,
• Biljana Bozic-Weber,
• Catherine E. Housecroft,
• Edwin C. Constable,
• Ernst Meyer and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2013, 4, 418–428, doi:10.3762/bjnano.4.49

• ); surface photovoltage (SPV); titanium dioxide (TiO2); Introduction Dye-sensitized solar cells (DSCs) provide a promising low-cost, high-efficiency third-generation photovoltaic concept based on the spectral sensitization of a nanoporous wide bandgap semiconductor [1][2]. In the past two decades DSCs have

Photocatalytic antibacterial performance of TiO₂ and Ag-doped TiO₂ against S. aureus. P. aeruginosa and E. coli

• Kiran Gupta,
• R. P. Singh,
• Ashutosh Pandey and
• Anjana Pandey

Beilstein J. Nanotechnol. 2013, 4, 345–351, doi:10.3762/bjnano.4.40

• is decreased. The photocatalytic activity of TiO2 nanoparticles depends not only on the properties of the TiO2 material itself, but also on the modification of TiO2 with metal or metal oxide. Previous studies reported that the addition of noble metal (silver and gold) in titanium dioxide enhances its

• comparison to those of the TiO2 nanoparticles because the metallic silver ions cause some changes in the electronic structure of the Ag-containing titanium dioxide nanoparticles [20]. Moreover, the PL intensity of Ag-doped TiO2 (7%) is lower in comparison to the case of 3% doping of Ag, and this can be

• cultures were grown in Luria broth and maintained on Luria agar plates. Cultures were grown with 2% inoculums at 25 °C until 0.2 optical density (O.D.) at 660 nm was achieved and used for antibacterial activity. Preparation of TiO2 nanoparticles Titanium dioxide nanoparticles were synthesized by an acid

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

• -oxide semiconductors, such as ZnO, titanium dioxide (TiO2), etc. The photogenerated free carriers allow efficient mineralization of toxic organic compounds [16] and hazardous inorganic materials [17], and microbial disinfection [18] through the creation of a hydroxyl radical (OH·), which acts as a

Self-assembled monolayers and titanium dioxide: From surface patterning to potential applications

• Yaron Paz

Beilstein J. Nanotechnol. 2011, 2, 845–861, doi:10.3762/bjnano.2.94

• and the rare photocatalytic properties of titanium dioxide provide a rationale for the study of systems comprising both. Such systems can be realized in the form of SAMs grown on TiO2 or, in a complementary manner, as TiO2 grown on SAMs. Accordingly, the current status of knowledge regarding SAMs on

• titanium dioxide based devices. Accordingly, particular attention is given to the description of a variety of methods and techniques aimed at utilizing the photocatalytic properties of titanium dioxide for patterning. Reports on a variety of applications are discussed. These examples, representing the

• areas of photovoltaics, microelectronics, microelectromechanics, photocatalysis, corrosion prevention and even biomedicine should be regarded as appetizers paving the way for further studies to be performed. Keywords: photocatalysis; remote degradation; self-assembled monolayers; titanium dioxide

Schottky junction/ohmic contact behavior of a nanoporous TiO₂ thin film photoanode in contact with redox electrolyte solutions

• Masao Kaneko,
• Hirohito Ueno and
• Junichi Nemoto

Beilstein J. Nanotechnol. 2011, 2, 127–134, doi:10.3762/bjnano.2.15

• [Fe(CN)6]4− around the redox potential of the iron complex. It was suggested that the iron complex forms a second Schottky junction for which the flat band potential (Efb) lies near the redox potential of the iron complex. Keywords: cyclic voltammogram of titanium dioxide photoanode; flat band