Surface-enhanced Raman spectroscopy of cell lysates mixed with silver nanoparticles for tumor classification

• Mohamed Hassoun,
• Iwan W.Schie,
• Tatiana Tolstik,
• Sarmiza E. Stanca,
• Christoph Krafft and
• Juergen Popp

Beilstein J. Nanotechnol. 2017, 8, 1183–1190, doi:10.3762/bjnano.8.120

• become electronically coupled, which results in a change of the surface plasmon resonance compared to individual particles. Figure 1b shows the effect of adding KCl to Ag nanoparticles on the optical absorption characteristics. The aggregated nanoparticles have a broad absorption band that allowed for

High photocatalytic activity of Fe₂O₃/TiO₂ nanocomposites prepared by photodeposition for degradation of 2,4-dichlorophenoxyacetic acid

• Shu Chin Lee,
• Hendrik O. Lintang and
• Leny Yuliati

Beilstein J. Nanotechnol. 2017, 8, 915–926, doi:10.3762/bjnano.8.93

• the impregnation method. The optical absorption properties of the nanocomposites prepared by the impregnation method were investigated (see Supporting Information File 1, Figure S3). The TiO2 (NT) sample absorbs light in the UV region and exhibits a characteristic band for TiO2 at about 370 nm due to

Selective detection of Mg²⁺ ions via enhanced fluorescence emission using Au–DNA nanocomposites

• Tanushree Basu,
• Khyati Rana,
• Niranjan Das and
• Bonamali Pal

Beilstein J. Nanotechnol. 2017, 8, 762–771, doi:10.3762/bjnano.8.79

• from the observed changes in the optical absorption, plasmon band, zeta potential, DLS particle size distribution, as well as TEM and AFM surface morphology analysis. Circular dichroism studies also revealed that DNA-functionalized AuNP binding caused a conformational change in the DNA structure. Due

• of the metal ion interaction [16]. The Au–DNA NC was found to be fairly effective for the detection of Mg2+ ions as compared to Ca2+ and Fe2+ ions present in aqueous solution. The enhanced binding ability is likely due to the smaller size of the Mg2+ ions. Results and Discussion The optical

• absorption of different bare and DNA-modified AuNPs (AuNS-1, AuNS-2, AuNS-3 and AuNS-4) is shown in Supporting Information File 1, Figure S1. It was found that due to their size dependency [17], the plasmon band shift (summarized in Supporting Information File 1, Table S1) occurred towards longer wavelengths

Investigation of the photocatalytic efficiency of tantalum alkoxy carboxylate-derived Ta₂O₅ nanoparticles in rhodamine B removal

• Subia Ambreen,
• Mohammad Danish,
• Narendra D. Pandey and
• Ashutosh Pandey

Beilstein J. Nanotechnol. 2017, 8, 604–613, doi:10.3762/bjnano.8.65

• gap energy [5][6][7][8], Ta2O5 nanoparticles are an open area for researchers. Tantalum pentoxide is an n-type semiconductor. It absorbs only UV light due to its wide band gap. Nevertheless, band gap modification through various methods has been proven to be successful for the red-shift of the optical

• absorption of these materials [9][10][11]. Tantalum(V) alkoxides are important precursors for materials based on tantalum oxide in sol–gel processes. The reactions involved in sol–gel processes can be written as: An inorganic network is formed during hydrolysis the ends of which are occupied either by –OH

Study of the surface properties of ZnO nanocolumns used for thin-film solar cells

• Neda Neykova,
• Jiri Stuchlik,
• Karel Hruska,
• Ales Poruba,
• Zdenek Remes and
• Ognen Pop-Georgievski

Beilstein J. Nanotechnol. 2017, 8, 446–451, doi:10.3762/bjnano.8.48

• were prepared before by DC reactive magnetron sputtering. The optical absorption of the pristine ZnO layers as well as that of the substrates bearing the dense ZnO NCs was investigated by photothermal deflection spectroscopy (PDS) [16][17]. Furthermore, we investigated the changes in the PDS spectrum

• -plasma for 1, 5, 10 and 25 min. The measured PDS absorptance spectra reflect the absorption edge, Urbach tail, absorption on defects and free-carrier absorption (proportional to the concentration of free carriers). All optical absorptance spectra show the optical absorption edge at a photon energy of 3.3

• eV and the free-carrier absorption in the red and the infrared part of the spectrum below photon energies of 2 eV. The infrared optical absorption increases with hydrogen plasma treatment indicating the increase of the free-carrier concentration as described in the Drude model. The increase of the

Laser irradiation in water for the novel, scalable synthesis of black TiO_x photocatalyst for environmental remediation

• Massimo Zimbone,
• Giuseppe Cacciato,
• Mohamed Boutinguiza,
• Vittorio Privitera and
• Maria Grazia Grimaldi

Beilstein J. Nanotechnol. 2017, 8, 196–202, doi:10.3762/bjnano.8.21

• its low band gap and large optical absorption [20][21] in the visible and IR spectral range. This material has also encouraged theoretical studies due to its peculiarities related to the hydrogen insertion. In the case of TiO2 nanoparticles, hydrogen induces the amorphization of a layer at the surface

Optical and photocatalytic properties of TiO₂ nanoplumes

• Viviana Scuderi,
• Massimo Zimbone,
• Maria Miritello,
• Giuseppe Nicotra,
• Giuliana Impellizzeri and
• Vittorio Privitera

Beilstein J. Nanotechnol. 2017, 8, 190–195, doi:10.3762/bjnano.8.20

• synthesize black TiO2 with a large optical absorption in the visible and infrared region [15][16][17][18]. The amorphous shell on a crystalline nanoparticle core, causes the formation of intragap states [19], which are responsible for the high absorption of visible light (and consequently of the black color

Tandem polymer solar cells: simulation and optimization through a multiscale scheme

• Fanan Wei,
• Ligang Yao,
• Fei Lan,
• Guangyong Li and
• Lianqing Liu

Beilstein J. Nanotechnol. 2017, 8, 123–133, doi:10.3762/bjnano.8.13

• the incident light achieves relatively better performance than the configuration with PCPDTBT/PCBM at the front. As a lower band gap, active material, PCPDTBT has considerably stronger optical absorption than P3HT. Thus, if the sub-cell with PCPDTBT is put first, a large portion of light energy will

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

• was achieved by adding 10 µL of 100 μM BiotinDNA to the AuNPs water solutions. Characterization of nanoparticles Optical absorption measurements were performed with NanodropTM 1000 and Agilent 8453 spectrophotometers. Spectra were collected in the 200–800 nm range. Nanoparticles were analysed by using

Hydrophilic silver nanoparticles with tunable optical properties: application for the detection of heavy metals in water

• Paolo Prosposito,
• Federico Mochi,
• Erica Ciotta,
• Mauro Casalboni,
• Fabio De Matteis,
• Iole Venditti,
• Laura Fontana,
• Giovanna Testa and
• Ilaria Fratoddi

Beilstein J. Nanotechnol. 2016, 7, 1654–1661, doi:10.3762/bjnano.7.157

• was tested in water solution by monitoring the optical absorption changes in the presence of metal ions. A weak dependence of the peak wavelength as a function of the ion concentration was found. However, the large broadening of the SPR band and the high background of the absorption hindered the

• performed absorption measurements as a function of concentration of nickel ions. Figure 7a shows the optical absorption spectrum of the AgNP-3MPS solution with nickel for different ion concentrations in the range 1.0–0.1 ppm. Figure 7b presents the maximum wavelength of the absorption peak as a function of

Scanning probe microscopy studies on the adsorption of selected molecular dyes on titania

• Jakub S. Prauzner-Bechcicki,
• Lukasz Zajac,
• Piotr Olszowski,
• Res Jöhr,
• Antoine Hinaut,
• Thilo Glatzel,
• Bartosz Such,
• Ernst Meyer and
• Marek Szymonski

Beilstein J. Nanotechnol. 2016, 7, 1642–1653, doi:10.3762/bjnano.7.156

• low conversion efficiencies [1]. However, when the surface of a wide-band-gap material is covered with a sensitizer that absorbs light in the visible spectrum and enables charge transfer through the semiconductor–adsorbate interface, the situation changes dramatically. The optical absorption, and

High performance Ce-doped ZnO nanorods for sunlight-driven photocatalysis

• Bilel Chouchene,
• Tahar Ben Chaabane,
• Lavinia Balan,
• Emilien Girot,
• Kevin Mozet,
• Ghouti Medjahdi and
• Raphaël Schneider

Beilstein J. Nanotechnol. 2016, 7, 1338–1349, doi:10.3762/bjnano.7.125

• , electronic and photocatalytic properties have been investigated. Our results demonstrate that Ce-doping improves the optical absorption ability toward visible light wavelengths and thus the photocatalytic performances. ZnO:Ce rods allow the complete degradation of the Orange II dye in ca. 80 min under solar

Photocurrent generation in carbon nanotube/cubic-phase HfO₂ nanoparticle hybrid nanocomposites

• Protima Rauwel,
• Augustinas Galeckas,
• Martin Salumaa,
• Frédérique Ducroquet and
• Erwan Rauwel

Beilstein J. Nanotechnol. 2016, 7, 1075–1085, doi:10.3762/bjnano.7.101

• means of optical absorption and photoluminescence spectroscopy [25]. We have already reported elsewhere that the free-standing cubic HfO2 nanoparticles are luminescent on their own with characteristic emission in the blue-green region of the visible spectra. This may be attributed to surface defects

• nanotube structure, thus optical absorption and emission spectroscopy allow identification of the CNT chirality and diameter as well as quality in terms of nontubular carbon content and structural defects. The characterization of multiwalled CNTs, however, is challenging because of the involvement of

• several shells with different structure and typically higher defect concentration compared to single-walled CNTs. The optical absorption properties of the hybrid MWCNT:HfO2 nanocomposites deduced from the room temperature transmittance measurements of a colloidal suspension in ethanol are summarized in

Sandwich-like layer-by-layer assembly of gold nanoparticles with tunable SERS properties

• Zhicheng Liu,
• Lu Bai,
• Guizhe Zhao and
• Yaqing Liu

Beilstein J. Nanotechnol. 2016, 7, 1028–1032, doi:10.3762/bjnano.7.95

• sodium citrate solution was injected, as shown in Figure 1. The optical absorption peaks located at 520 and 532 nm indicate the strong surface plasmon resonance of the NPs. These uniform negatively charged citrate-protected Au NPs could be readily used in electrostatic LbL assembly. Typical sandwich-like

Optical absorption signature of a self-assembled dye monolayer on graphene

• Tessnim Sghaier,
• Sylvain Le Liepvre,
• Céline Fiorini,
• Ludovic Douillard and
• Fabrice Charra

Beilstein J. Nanotechnol. 2016, 7, 862–868, doi:10.3762/bjnano.7.78

• combining two successive images with downward and upward slow-scan directions. Optical absorption spectra at normal incidence were obtained with a Perkin-Elmer Lambda 650 spectrometer. Optical microspectroscopy was adapted on an Olympus IX71 microscope equipped with an Ocean Optics spectrometer QE-Pro

Selective photocatalytic reduction of CO₂ to methanol in CuO-loaded NaTaO₃ nanocubes in isopropanol

• Tianyu Xiang,
• Feng Xin,
• Jingshuai Chen,
• Yuwen Wang,
• Xiaohong Yin and
• Xiao Shao

Beilstein J. Nanotechnol. 2016, 7, 776–783, doi:10.3762/bjnano.7.69

• –precipitation mechanism, where the concentration of the NaOH solution played a crucial role on the morphology of the crystal. This was confirmed in our work. Figure 3 shows UV–vis diffuse reflectance spectra and optical absorption edges of NaTaO3 nanocubes prepared with different concentrations of NaOH. From

• isopropanol to methanol was also proposed and explained by band theory. XRD patterns of NaTaO3 nanocubes. SEM images of NaTaO3 nanocubes: (a) 1M-NaTaO3, (b) 2M-NaTaO3, (c) 3M-NaTaO3, and (d) 4M-NaTaO3. UV–vis diffuse reflectance spectra (a) and optical absorption band edges (b) of NaTaO3 nanocubes. XRD

Correlative infrared nanospectroscopic and nanomechanical imaging of block copolymer microdomains

• Benjamin Pollard and
• Markus B. Raschke

Beilstein J. Nanotechnol. 2016, 7, 605–612, doi:10.3762/bjnano.7.53

• the s-SNOM spectral phase in our analysis, which for weak molecular oscillators provides a good approximation of the spectral shape of the optical absorption or extinction coefficient [1]. Gaussian resonance curves are computationally fit to the spectra in order to extract peak position and

Bacteriorhodopsin–ZnO hybrid as a potential sensing element for low-temperature detection of ethanol vapour

• Saurav Kumar,
• Sudeshna Bagchi,
• Senthil Prasad,
• Anupma Sharma,
• Ritesh Kumar,
• Rishemjit Kaur,
• Jagvir Singh and
• Amol P. Bhondekar

Beilstein J. Nanotechnol. 2016, 7, 501–510, doi:10.3762/bjnano.7.44

• scanning electron microscope (SEM, Hitachi) with an accelerating voltage of 5–15 kV. The film thickness was measured using a surface profilometer in contact mode (Taly-surf PGI 120). Raman and optical spectral analysis The optical absorption spectra of all the nanostructures were recorded using a UV–vis

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

• cantilever geometry. As an alternative approach, the improvement of excitation efficiency using a short wavelength laser beam has been reported [27]. The high efficiency when using a short wavelength laser beam compared to a long wavelength laser beam is explained by the optical absorption characteristics of

Chemiresistive/SERS dual sensor based on densely packed gold nanoparticles

• Sanda Boca,
• Cosmin Leordean,
• Simion Astilean and
• Cosmin Farcau

Beilstein J. Nanotechnol. 2015, 6, 2498–2503, doi:10.3762/bjnano.6.259

• biological molecules. Optical absorption spectra of the colloidal suspension recorded before and after incubation with folic acid confirmed the capping of AuNPs (redshift of the dipolar plasmon band) (Figure S1, Supporting Information File 1). DLS measurements correlate with the optical absorption results

Influence of wide band gap oxide substrates on the photoelectrochemical properties and structural disorder of CdS nanoparticles grown by the successive ionic layer adsorption and reaction (SILAR) method

• Mikalai V. Malashchonak,
• Alexander V. Mazanik,
• Olga V. Korolik,
• Еugene А. Streltsov and
• Anatoly I. Kulak

Beilstein J. Nanotechnol. 2015, 6, 2252–2262, doi:10.3762/bjnano.6.231

• optical absorption and photocarrier recombination. The maximal IPCE values for the In2O3/CdS and ZnO/CdS heterostructures are attained at N ≈ 20, whereas for TiO2/CdS, the appropriate N value is an order of magnitude higher. The photocurrent and Raman spectroscopy studies of CdS nanoparticles revealed the

• , is non-monotonic and influenced by the competition of two processes: the increase in the optical absorption with N (i.e., with the amount of CdS) and the simultaneous enhancement of the recombination role due to the increased distance the photogenerated charge carriers must overcome. The number of N

• substrate, ensuring improved electron transfer from the NPs to the oxide matrix. For all types of WBGO substrates the dependence of IPCE (Y) on the number of SILAR cycles passes through a maximum (Figure 2d). The increase in IPCE in the range of small N is naturally related to the increase in optical

Nonlinear optical properties of near-infrared region Ag₂S quantum dots pumped by nanosecond laser pulses

• Li-wei Liu,
• Si-yi Hu,
• Yin-ping Dou,
• Tian-hang Liu,
• Jing-quan Lin and
• Yue Wang

Beilstein J. Nanotechnol. 2015, 6, 1781–1787, doi:10.3762/bjnano.6.182

• ionic currents contribute to the absorption of the Ag2S QDs, which is affected by the pulse width waveforms. It could also be explained by an effect of nonlinear optical absorption that depends othe pump energy. This may reflect the dynamic behavior of gain or feedback mechanisms in the nonlinear

Current–voltage characteristics of manganite–titanite perovskite junctions

• Benedikt Ifland,
• Patrick Peretzki,
• Birte Kressdorf,
• Philipp Saring,
• Andreas Kelling,
• Michael Seibt and
• Christian Jooss

Beilstein J. Nanotechnol. 2015, 6, 1467–1484, doi:10.3762/bjnano.6.152

• , mixed halides. The constituents for manganite oxide are: A = rare earth, alkali metal, mixed composition, B = Mn, and X = O. The organic/inorganic halide perovskites exhibit good optical absorption and favorable electrical properties, thus offering the possibility for use in high efficiency solar cells

Electronic interaction in composites of a conjugated polymer and carbon nanotubes: first-principles calculation and photophysical approaches

• Florian Massuyeau,
• Jany Wéry,
• Jean-Luc Duvail,
• Serge Lefrant,
• Abu Yaya,
• Chris Ewels and
• Eric Faulques

Beilstein J. Nanotechnol. 2015, 6, 1138–1144, doi:10.3762/bjnano.6.115

• transfer between the polymer and the nanotubes is supported by examining steady-state PL energies of a series of composites films containing both metallic and SC nanotubes with x increasing from 0% to 64% compared to the optical absorption of SWNTs (Figure 5). We have substracted the absorption background

• of SWNTs which is due to the π plasmons. In this way, only the contribution of SC and metallic tubes is clearly displayed. These experiments show that there is substantial spectral overlap of PL and optical absorption of SWNTs which could, in principle, favor the occurrence of Förster energy transfer

Experimental determination of the light-trapping-induced absorption enhancement factor in DSSC photoanodes

• Serena Gagliardi and
• Mauro Falconieri

Beilstein J. Nanotechnol. 2015, 6, 886–892, doi:10.3762/bjnano.6.91

• , which therefore enhances the optical absorption. This approach describes a useful, functional characterization for the study of new morphologies of DSSC photoanodes. In fact, it can be applied both to simple structures and layered structures because it considers the photoanode as an effective layer and