Precise quantification of silica and ceria nanoparticle uptake revealed by 3D fluorescence microscopy

• Adriano A. Torrano and
• Christoph Bräuchle

Beilstein J. Nanotechnol. 2014, 5, 1616–1624, doi:10.3762/bjnano.5.173

• nanoparticles were labeled with perylene dye. A detailed description of the synthesis can be found in a previous publication [41]. From experiments on the labeling efficiency of perylene, it was estimated that dye molecules cover only about 0.16% of the surface of the particles and, therefore, should not

Near-field photochemical and radiation-induced chemical fabrication of nanopatterns of a self-assembled silane monolayer

• Ulrich C. Fischer,
• Carsten Hentschel,
• Florian Fontein,
• Linda Stegemann,
• Christiane Hoeppener,
• Harald Fuchs and
• Stefanie Hoeppener

Beilstein J. Nanotechnol. 2014, 5, 1441–1449, doi:10.3762/bjnano.5.156

• -assembled monolayer (SAM) of (3-aminopropyl)triethoxysilane (APTES) is explored with three different processes: 1) a near-field photochemical process by photochemical bleaching of a monomolecular layer of dye molecules chemically bound to an APTES SAM, 2) a chemical process induced by oxygen plasma etching

• nanostructures. A sandwich between a metal nanostructure produced by CL and a monomolecular Langmuir–Blodgett layer of dye molecules was irradiated with light. Removing the metal mask revealed a chemical nanostructure consisting of regions of bleached and unbleached dye. The metal mask has an inhibitory function

• and protects the dye from photochemical bleaching by quenching the excited state of the dye molecules through energy transfer from the excited state to the metal [23]. In this near-field photochemical process it is the near field of the dipole-excited molecule, not the near field of the metal mask

Characterization and photocatalytic study of tantalum oxide nanoparticles prepared by the hydrolysis of tantalum oxo-ethoxide Ta₈(μ₃-O)₂(μ-O)₈(μ-OEt)₆(OEt)₁₄

• Subia Ambreen,
• N D Pandey,
• Peter Mayer and
• Ashutosh Pandey

Beilstein J. Nanotechnol. 2014, 5, 1082–1090, doi:10.3762/bjnano.5.121

• observed that on increasing the amount of dye from 2.5 ppm to 12.5 ppm the rate of degradation of the dye increases but a further increase of the dye concentration decreases the degradation rate (Figure 13). With the increase in dye concentration the number of dye molecules available for excitation and

• , 0.8 mg/mL and 1.1 mg/mL) of Ta2O5 nanoparticles as photocatalysts were taken in 50 mL of distilled water and sonicated for 5 min. Then 12.5 ppm of rhodamine B was added to it. To attain an adsorption–desorption equilibrium between the dye molecules and the catalyst surface, the solution was stirred

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

• photo-induced electron transfer from the excited dye molecules to RGOx. The slight blue shift suggests that an intermolecular π-π stacking interaction between RGO24 and EY is stronger than the interaction between GO and EY [20]. To further confirm the increased ability to transfer electrons between RGOx

• absorb photons and transfer photo-induced electrons into the sp2 domains of RGO24 for hydrogen evolution. Nevertheless, with a further increase of the concentration of EY, more and more free EY molecules are in solution. These free dye molecules cannot effectively transfer their photo-excited electrons

Enhanced photocatalytic activity of Ag–ZnO hybrid plasmonic nanostructures prepared by a facile wet chemical method

• Sini Kuriakose,
• Vandana Choudhary,
• Biswarup Satpati and
• Satyabrata Mohapatra

Beilstein J. Nanotechnol. 2014, 5, 639–650, doi:10.3762/bjnano.5.75

• nanostructures, is dependent on the alignment of electronic band structure of the noble metal and semiconductor. Furthermore, irradiation with sun light leads to the excitation of MB dye molecules adsorbed onto the ZnO nanostructures. The photoexcited MB molecules transfer electrons into the conduction band of

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

• ) 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

• be multi-functional by hosting luminescent dye molecules or magnetic nanoparticles. As the growth rate over the side facets of a ZnO nanorod is much slower than that over the top facet, it would be more challenging to encapsulate large nanoparticles with size beyond the 100 nm regime into ZnO nanorod

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

• to 270 m3 of wastewater has to be treated prior to the release into the environment [1]. Conventional biological treatment plants are not effective in the removal of colour dye effluents, because of the aromatic structure of the large dye molecules, which provides chemical stability and, thus, also a

Dye-doped spheres with plasmonic semi-shells: Lasing modes and scattering at realistic gain levels

• Nikita Arnold,
• Boyang Ding,
• Calin Hrelescu and
• Thomas A. Klar

Beilstein J. Nanotechnol. 2013, 4, 974–987, doi:10.3762/bjnano.4.110

• which a dye-doped dielectric sphere was covered by a semi-shell of noble metals. The authors of [50][51] assumed metal-capped and dye-doped spheres comprising a spectrally flat, dispersion-less gain. This does not reflect realistic dye molecules, which provide gain only within a limited spectral range

• fluoresces in the visible region. We tune specific plasmonic resonances into the emission maximum of the dye molecules by adjusting the thickness of the silver caps on the dye-doped spheres. In particular, we assume a doping concentration, a size of the spheres and the type of dye molecules as given by the

• illumination from the silver-capped side and (90,0) denotes an illumination from the side, in which the electric field is parallel to the z-axis such that axial plasmonic modes can be excited. The thickness of the silver shell and the concentration of the dye molecules are varied throughout the paper

Optimization of solution-processed oligothiophene:fullerene based organic solar cells by using solvent additives

• Gisela L. Schulz,
• Marta Urdanpilleta,
• Roland Fitzner,
• Eduard Brier,
• Elena Mena-Osteritz,
• Egon Reinold and
• Peter Bäuerle

Beilstein J. Nanotechnol. 2013, 4, 680–689, doi:10.3762/bjnano.4.77

• BHJSCs is fabricated by simultaneous deposition of both, the electron donor (D) as a p-type and the electron acceptor (A) as n-type semiconducting material. The field can be divided based on the type of donor material; polymer or oligomer/dye molecules. Oligomers or, as they are sometimes referred to

Apertureless scanning near-field optical microscopy of sparsely labeled tobacco mosaic viruses and the intermediate filament desmin

• Alexander Harder,
• Mareike Dieding,
• Volker Walhorn,
• Sven Degenhard,
• Andreas Brodehl,
• Christina Wege,
• Hendrik Milting and
• Dario Anselmetti

Beilstein J. Nanotechnol. 2013, 4, 510–516, doi:10.3762/bjnano.4.60

• illuminated AFM cantilever tip apex exposes strongly confined non-propagating electromagnetic fields that can serve as a coupling agent for single dye molecules. Thus, combining both techniques by means of apertureless scanning near-field optical microscopy (aSNOM) enables concurrent high resolution

• over a comparably broad phase window of 20–40°. Topography and processed near-field fluorescence can then be superimposed without further lateral adjustment (Figure 3c). The combined data allow to easily determine the degree of modification and the loci of anchor groups equipped with dye molecules

• and added in a 10:1 molar excess. After 30 minutes the unbound dye is blocked by the addition of cysteamine (1 M in H2O to a concentration of 100 mM and incubation for 1 hour at room temperature). The labeled desmin is separated from free dye molecules by dialysis (against 8 M urea, 5 mM Tris-HCl, 1

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

• -based electrolyte and a platinum counter electrode as depicted in Figure 1. Upon visible-light excitation, dye molecules inject electrons into the conduction band, Ecb, of the semiconductor; the oxidized dye is subsequently reduced by the redox couple of the surrounding electrolyte. The generated

• investigations [39][40]. KPFM studies in UHV conditions of rutile TiO2 decorated with either nanometer-sized Pt clusters [41] or single dye molecules [42] revealed a significant impact of single particles on the surface dipole. We have investigated the surface parameters of DSC photoelectrodes on the nanoscale

• variations may be due to varying material properties in general. In any case, such variations, which are clearly detectable by KPFM, may obstruct the optimal attachment of dye molecules and thus reduce the solar cell performance [25]. Microscopic surface photovoltage By combining a tunable illumination

Near-field effects and energy transfer in hybrid metal-oxide nanostructures

• Ulrich Herr,
• Barat Achinuq,
• Cahit Benel,
• Giorgos Papageorgiou,
• Manuel Goncalves,
• Johannes Boneberg,
• Paul Leiderer,
• Paul Ziemann,
• Peter Marek and
• Horst Hahn

Beilstein J. Nanotechnol. 2013, 4, 306–317, doi:10.3762/bjnano.4.34

• the organic dye molecules and the semiconductor to make the process efficient. The Grätzel cell thus mimics the natural process of photosynthesis, where light harvesting, energy transfer to a reaction center, and conversion to chemical energy by an electron-transfer reaction, take place at different

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

• OH-terminated silica surfaces. Amino-functionalized nanostructures have been successfully modified by the covalent binding of functional fluorescein dye molecules. Upon excitation, the dye-functionalized structures show only weak fluorescence, which may be an indication of a relatively low surface

• coverage of the dye molecules on length scale that is not accessible by standard AFM measurements. Keywords: AFM lithography; amino-functionalization; local anodic oxidation; octadecyl-trichlorosilane; silicon oxide nanostructures; Introduction Local anodic oxidation (LAO) nanolithography is a reliable

• molecules should in principle be distinguishable by the amplitude–phase–distance curve technique. Conclusion In conclusion, a route for a controlled covalent functionalization of silicon oxide nanostructures with an amino-terminated silane and FITC dye molecules has been successfully realized. The formation

Reduced electron recombination of dye-sensitized solar cells based on TiO₂ spheres consisting of ultrathin nanosheets with [001] facet exposed

• Hongxia Wang,
• Meinan Liu,
• Cheng Yan and
• John Bell

Beilstein J. Nanotechnol. 2012, 3, 378–387, doi:10.3762/bjnano.3.44

• [001] and [101] facets of TiO2 are expected to have a profound effect on the chemicophysical processes in DSCs as well. Fan et al. reported that the [001] surface can absorb more dye molecules compared to the [101] surface [10]. However, the influence of the TiO2 [001] facet on the kinetics of electron

• the DSC made from paste B is due to the availability of more TiO2 particles in the film, which can absorb more dye molecules, leading to a stronger light absorption. The Jsc of the DSC made from paste B was further increased from 15.6 mA/cm2 (Figure 2b, curve C) to 18.2 mA/cm2 when the TiO2 film was

• (–COOH) [4], leading to the protonation of the surface of TiO2 and the downward shift of the Ec. The more dye molecules are adsorbed on the TiO2 film, the more downward shift is expected for the Ec. Effect of TiCl4 treatment The strategy of treating TiO2 mesoporous films with TiCl4 aqueous solution has

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

• studied quite thoroughly for both organothiolated SAMs on metals and organosilanes on silicon. The appearance of dye-sensitized solar cells [85], based on (disordered) dye molecules attached to the surface of nanoparticulate titanium dioxide, provoked interest also in the charge transport from SAMs to

Highly efficient ZnO/Au Schottky barrier dye-sensitized solar cells: Role of gold nanoparticles on the charge-transfer process

• Tanujjal Bora,
• Htet H. Kyaw,
• Soumik Sarkar,
• Samir K. Pal and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2011, 2, 681–690, doi:10.3762/bjnano.2.73

• of the Au nanoparticles, enhanced power-conversion efficiency (PCE) of 6.49% for small-area (0.1 cm2) ZnO/Au-nanocomposite DSSC was achieved compared to the 5.34% efficiency of the bare ZnO nanorod DSSC. The TCSPC studies revealed similar dynamics for the charge transfer from dye molecules to ZnO

• sensitizer dye molecules, the photoexcited electrons in the Au nanoparticles are transferred to the conduction band (CB) of ZnO, and then diffuse through the ZnO nanorods towards the conducting fluorine-doped tin oxide (FTO) substrate resulting in higher photocurrent and photovoltage, as observed. The

• . The formation of the Schottky barrier in the ZnO/Au-nanocomposite system and the possible electron-transfer path in the ZnO/Au DSSC is schematically represented in Figure 4. Upon irradiation, the electrons from excited dye molecules are injected into the Au nanoparticles embedded in the surface of the

Distance dependence of near-field fluorescence enhancement and quenching of single quantum dots

• Volker Walhorn,
• Jan Paskarbeit,
• Heinrich Gotthard Frey,
• Alexander Harder and
• Dario Anselmetti

Beilstein J. Nanotechnol. 2011, 2, 645–652, doi:10.3762/bjnano.2.68

• organic dye molecules were obtained and discussed recently [13]. At larger gap sizes we observed a significant distance dependence of the fluorescence emission. A relative fluorescence maximum at z ≈ 22 nm was followed by a drop of the emission intensity at a surface distance of approximately 52 nm

Characterization of protein adsorption onto FePt nanoparticles using dual-focus fluorescence correlation spectroscopy

• Pauline Maffre,
• Karin Nienhaus,
• Faheem Amin,
• Wolfgang J. Parak and
• G. Ulrich Nienhaus

Beilstein J. Nanotechnol. 2011, 2, 374–383, doi:10.3762/bjnano.2.43

• , we employed the same type of NP as in our previous work [11], namely, FePt cores that were rendered fluorescent by incorporating a small number of red fluorescent dye molecules (DY-636) in the polymer-coating surrounding the core [29]. The polymer shell contained a large number of carboxyl groups

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

• irradiation due to the large electron density injected from the photoexcited state of TiO2-attached dye molecules. The CV of the nanoporous TiO2 (T/SP, Solaronix) thin film photoanode soaked in an aqueous solution containing only 400 μM [Fe(CN)6]4− (+ 0.1 M Na2SO4, pH 8.5) without methanol is shown in Figure

Enhanced visible light photocatalysis through fast crystallization of zinc oxide nanorods

• Sunandan Baruah,
• Mohammad Abbas Mahmood,
• Myo Tay Zar Myint,
• Tanujjal Bora and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2010, 1, 14–20, doi:10.3762/bjnano.1.3

• exposed surface area available for adsorption of the dye molecules in the different samples are presented. Figure 3 shows the photocatalytic results comparing the ZnO nanoparticle film and the nanorods of different sizes and density (thereby offering different surface to volume ratios) on glass substrate