Colloidal solution of silver nanoparticles for label-free colorimetric sensing of ammonia in aqueous solutions

• Alessandro Buccolieri,
• Antonio Serra,
• Gabriele Giancane and
• Daniela Manno

Beilstein J. Nanotechnol. 2018, 9, 499–507, doi:10.3762/bjnano.9.48

• sensors [14]. The optical properties of gold and silver nanoparticles in the UV–vis region (200–800 nm) are well known. As an example, the peak of the optical absorption SPR is a feature of the colloidal metal nanoparticle solutions. The exact position of the absorption maximum and the shape of the peak

• are strongly dependent on the size, shape and interparticle distance of the nanoparticles, but also on the surrounding environment and on the number of interacting nanoparticles [15]. The optical properties of nanoparticles have allowed researchers to develop new diagnostic methods that are

• concentrations ranging from 0.01 to 0.2 ppm, high concentrations of ammonia ranging from 20 to 350 ppm and especially intermediate or physiological ammonia concentrations ranging from 0.5 to 10 ppm. Results and Discussion To analyse the role of ammonia on the optical properties of colloidal solutions of silver

Kinetics of solvent supported tubule formation of Lotus (Nelumbo nucifera) wax on highly oriented pyrolytic graphite (HOPG) investigated by atomic force microscopy

• Sujit Kumar Dora,
• Kerstin Koch,
• Wilhelm Barthlott and
• Klaus Wandelt

Beilstein J. Nanotechnol. 2018, 9, 468–481, doi:10.3762/bjnano.9.45

• , hydrophobicity, protection of photo synthetic cells, interaction with chemicals and other organisms, providing optical properties etc. [2][3][4][5][6][7][8][9]. Plant waxes are a conglomerate of various long chain (>C20) hydrocarbons, aldehydes, ketones, acids, alcohols etc. [10]. Further, cyclic compounds, e.g

High-contrast and reversible scattering switching via hybrid metal-dielectric metasurfaces

• Jonathan Ward,
• Khosro Zangeneh Kamali,
• Lei Xu,
• Guoquan Zhang,
• Andrey E. Miroshnichenko and
• Mohsen Rahmani

Beilstein J. Nanotechnol. 2018, 9, 460–467, doi:10.3762/bjnano.9.44

• magnetic modes, and subsequently, the Kerker condition, as a directive radiation pattern with zero backscattering, via temperature control as a versatile tool. This control allows precise tuning optical properties of the system and stimulating switchable sharp spectral Fano-like resonance. Furthermore, it

• ; Introduction Metasurfaces are thin and flat surfaces that are created using subwavelength optical antennas with various optical properties patterned at interfaces [1][2], enabling control over the polarization, phase, amplitude, and dispersion of light. Metasurfaces are growing in popularity as their optical

• an easy and reversible way. The large thermo-optical coefficient of dielectrics allows for active control of the devices optical properties by heating. This tunability can be done in a reversible and dynamic way using a parameter that is controlled externally. This tunable device then allows for flat

Influence of the preparation method on the photocatalytic activity of Nd-modified TiO₂

• Patrycja Parnicka,
• Paweł Mazierski,
• Tomasz Grzyb,
• Wojciech Lisowski,
• Ewa Kowalska,
• Bunsho Ohtani,
• Adriana Zaleska-Medynska and
• Joanna Nadolna

Beilstein J. Nanotechnol. 2018, 9, 447–459, doi:10.3762/bjnano.9.43

• , due to the 4f electron structure, can act as conversion luminescent media [14][16][17][18]. Neodymium (Nd3+) ions are well known as one of the more interesting lanthanides due to unique electronic and optical properties [19][20]. Several reports suggested that the transformation of light from near

Facile synthesis of ZnFe₂O₄ photocatalysts for decolourization of organic dyes under solar irradiation

• Arjun Behera,
• Debasmita Kandi,
• Sanjit Manohar Majhi,
• Satyabadi Martha and
• Kulamani Parida

Beilstein J. Nanotechnol. 2018, 9, 436–446, doi:10.3762/bjnano.9.42

• magnetic in nature [10][11][12][13]. Among different metal ferrite materials, zinc ferrite (ZnFe2O4) plays a significant role because of its low band gap (1.88 eV), high thermal conductivity, good chemical stability, higher specific strength, magneto-resistive and magneto optical properties and low

Engineering of oriented carbon nanotubes in composite materials

• Razieh Beigmoradi,
• Abdolreza Samimi and
• Davod Mohebbi-Kalhori

Beilstein J. Nanotechnol. 2018, 9, 415–435, doi:10.3762/bjnano.9.41

• , many researchers indicate that the macroscopic optical properties of CNTs depend on the tube orientation with respect to the direction of beam propagation. Thus, FTIR results can be related to the morphology of the CNT mixture such as bundling, length and straightness [125]. X-ray photoelectron

Temperature-tunable lasing from dye-doped chiral microdroplets encapsulated in a thin polymeric film

• Gia Petriashvili,
• Mauro Daniel Luigi Bruno,
• Maria Penelope De Santo and
• Riccardo Barberi

Beilstein J. Nanotechnol. 2018, 9, 379–383, doi:10.3762/bjnano.9.37

• the field of sensors and for the development of anti-counterfeiting labels. Keywords: chiral microdroplets; dye-doped cholesteric liquid crystals; laser; polymeric films; temperature tuning; Introduction Liquid crystalline materials show peculiar optical properties. Cholesteric liquid crystals (CLCs

Sugarcane juice derived carbon dot–graphitic carbon nitride composites for bisphenol A degradation under sunlight irradiation

• Lan Ching Sim,
• Jing Lin Wong,
• Chen Hong Hak,
• Jun Yan Tai,
• Kah Hon Leong and
• Pichiah Saravanan

Beilstein J. Nanotechnol. 2018, 9, 353–363, doi:10.3762/bjnano.9.35

• urea and sugarcane juice as starting materials. The chemical composition, morphological structure and optical properties of the composites and CDs were characterized using various spectroscopic techniques as well as transmission electron microscopy. X-ray photoelectron spectroscopy (XPS) results

• degradation of endocrine disrupting chemicals (EDCs). Bisphenol A (BPA) was chosen as a model pollutant under natural sunlight irradiation. Herein, the structural and optical properties of samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), photoluminescence

• content. Optical properties Figure 3a shows the UV–vis absorption spectra of CDs in an aqueous solution in the range from 200 nm to 750 nm. The obvious peak at about 330 nm could be ascribed to the n–π* transition of C=O bond [56]. The inset of Figure 3a shows that the CD solution emitted a strong blue

Al₂O₃/TiO₂ inverse opals from electrosprayed self-assembled templates

• Arnau Coll,
• Sandra Bermejo,
• David Hernández and
• Luís Castañer

Beilstein J. Nanotechnol. 2018, 9, 216–223, doi:10.3762/bjnano.9.23

• material deposition process with the maximum temperature that the polymeric nanoparticles can sustain, which is typically below 90–100 °C. This low temperature reduces the choices of materials that have suitable optical properties for a given application [35][36]. As an example, TiO2 deposited at <150 °C

Dopant-stimulated growth of GaN nanotube-like nanostructures on Si(111) by molecular beam epitaxy

• Alexey D. Bolshakov,
• Alexey M. Mozharov,
• Georgiy A. Sapunov,
• Igor V. Shtrom,
• Nickolay V. Sibirev,
• Vladimir V. Fedorov,
• Evgeniy V. Ubyivovk,
• Maria Tchernycheva,
• George E. Cirlin and
• Ivan S. Mukhin

Beilstein J. Nanotechnol. 2018, 9, 146–154, doi:10.3762/bjnano.9.17

• about half of the nanostructure length and has a horizontal bottom. A bright shade of a thin carbon layer supporting the nanostructure during the measurement can be seen to the right of the nanostructure. Optical properties of silicon-doped GaN nanostructures In this work, we study the influence of the

Co-reductive fabrication of carbon nanodots with high quantum yield for bioimaging of bacteria

• Jiajun Wang,
• Xia Liu,
• Gesmi Milcovich,
• Tzu-Yu Chen,
• Edel Durack,
• Sarah Mallen,
• Yongming Ruan,
• Xuexiang Weng and
• Sarah P. Hudson

Beilstein J. Nanotechnol. 2018, 9, 137–145, doi:10.3762/bjnano.9.16

• sp2-bonded carbon atoms [36], which agrees well with the proposed co-reduction pathway to effectively produce more reduced carbon with a higher C-dot QY. UV–vis absorption and fluorescence properties were studied at room temperature to explore the optical properties of the three optimized C-dots. As

Design of photonic microcavities in hexagonal boron nitride

• Sejeong Kim,
• Milos Toth and
• Igor Aharonovich

Beilstein J. Nanotechnol. 2018, 9, 102–108, doi:10.3762/bjnano.9.12

• silicon carbide [19][20]. The hybrid approach is easier from the fabrication point of view but is inherently limited by the fact that the electric field maxima of optical modes are situated within the cavities, and optimal coupling therefore remains a challenge. The optical properties of hBN make it an

Thermo- and electro-optical properties of photonic liquid crystal fibers doped with gold nanoparticles

• Agata Siarkowska,
• Miłosz Chychłowski,
• Daniel Budaszewski,
• Bartłomiej Jankiewicz,
• Bartosz Bartosewicz and
• Tomasz R. Woliński

Beilstein J. Nanotechnol. 2017, 8, 2790–2801, doi:10.3762/bjnano.8.278

• , Warsaw, Poland 10.3762/bjnano.8.278 Abstract Thermo- and electro-optical properties of a photonic liquid crystal fiber (PLCF) enhanced by the use of dopants have been investigated. A 6CHBT nematic liquid crystal was doped with four different concentrations of gold nanoparticles (NPs), 0.1, 0.3, 0.5 and

• transition temperature, thus improving the thermo- and electro-optical properties of the PLCF. Keywords: fiber optics; gold nanoparticle; liquid crystal; phase transition temperature; photonic crystal fiber; Introduction Since their discovery in 1888, liquid crystals (LCs) have attracted nonstop research

• interest for their unique electro-optical properties that are essential in various optical and photonic applications such as LC displays, attenuators, tunable polarizers, spatial light modulators, photonic sensors, etc. [1][2]. However, current values of electro-optic response times and switch-on voltages

Patterning of supported gold monolayers via chemical lift-off lithography

• Liane S. Slaughter,
• Kevin M. Cheung,
• Sami Kaappa,
• Huan H. Cao,
• Qing Yang,
• Thomas D. Young,
• Andrew C. Serino,
• Sami Malola,
• Jana M. Olson,
• Stephan Link,
• Hannu Häkkinen,
• Anne M. Andrews and
• Paul S. Weiss

Beilstein J. Nanotechnol. 2017, 8, 2648–2661, doi:10.3762/bjnano.8.265

• on PDMS samples were stable for at least six months (Figure S6, Supporting Information File 1). These results suggest that while the optical properties of the lifted-off monolayers are different from those of bulk Au (i.e., the former are optically transparent), lifted-off Au monolayers are

PTFE-based microreactor system for the continuous synthesis of full-visible-spectrum emitting cesium lead halide perovskite nanocrystals

• Chengxi Zhang,
• Weiling Luan,
• Yuhang Yin and
• Fuqian Yang

Beilstein J. Nanotechnol. 2017, 8, 2521–2529, doi:10.3762/bjnano.8.252

• nanocrystals are continuously synthesized via a microreactor system consisting of poly(tetrafluoroethylene) (PTFE) capillaries. The synthesized nanocrystals possess excellent optical properties, including a full width at half maximum of 19–35 nm, high fluorescence quantum yield of 47.8–90.55%, and

• spectra of the CsPbX3 nanocrystals cover the range of 450–700 nm. The prepared nanocrystals possess excellent optical properties with a FWHM of 19–35 nm and a high fluorescence quantum yield (FLQY) of 47.8–90.55%. The CsPbX3 nanocrystals prepared by the PTFE-based microreactor system exhibit three

Refractive index sensing and surface-enhanced Raman spectroscopy using silver–gold layered bimetallic plasmonic crystals

• Somi Kang,
• Sean E. Lehman,
• Matthew V. Schulmerich,
• An-Phong Le,
• Tae-woo Lee,
• Stephen K. Gray,
• Rohit Bhargava and
• Ralph G. Nuzzo

Beilstein J. Nanotechnol. 2017, 8, 2492–2503, doi:10.3762/bjnano.8.249

• that would otherwise degrade their performance in use. Efforts in this field have been directed particularly toward the unique optical properties of periodic nanostructures because of their capacities for extraordinary optical transmission, visual wavelength responsiveness, and high optical sensitivity

• confirm this correlation between the magnitude of the SERS enhancement and the underlying optical properties of the plasmonic substrate. FDTD simulations theoretically confirm the underlying mechanism and optimized PC structures for SERS enhancement. Calculated top field intensity distributions at 5 nm

• spectroscopic response of the PC optic. These correlations are not fully predictive of optimal performance in SERS for a broader range of PC design rules. The larger data, for example, specifically show that the p580 PC is not the best design rule for SERS measurements and that the optical properties needed to

Dynamic behavior of a nematic liquid crystal mixed with CoFe₂O₄ ferromagnetic nanoparticles in a magnetic field

• Emil Petrescu,
• Cristina Cirtoaje and
• Cristina Stan

Beilstein J. Nanotechnol. 2017, 8, 2467–2473, doi:10.3762/bjnano.8.246

• , carbon nanotubes and quantum dots [14][15][16][17][18][19][20][21][22], yielding modified optical properties [23][24][25]. The main advantages of nanoparticles are given by their small dimensions and unique physical properties that strongly affect the local nematic order [26]. This leads to significant

Laser-assisted fabrication of gold nanoparticle-composed structures embedded in borosilicate glass

• Nikolay Nedyalkov,
• Mihaela Koleva,
• Nadya Stankova,
• Rosen Nikov,
• Mitsuhiro Terakawa,
• Yasutaka Nakajima,
• Lyubomir Aleksandrov and
• Reni Iordanova

Beilstein J. Nanotechnol. 2017, 8, 2454–2463, doi:10.3762/bjnano.8.244

• , the color of the irradiated areas changed to pink, with a corresponding well-defined peak in the absorbance spectrum. We relate this effect to the formation of gold nanoparticles with optical properties defined by plasmon excitation. Their presence was confirmed by high-resolution TEM analysis. No

• nanoparticle formation was observed in the samples irradiated by nanosecond pulses at 355, 532 and 1064 nm. The optical properties of the irradiated areas were found to depend on the laser processing parameters; these properties were studied based on Mie theory, which was also used to correlate the

• glass; laser nanostructuring; optical properties of composite materials; Introduction The unique optical properties of noble-metal nanoparticles continue to attract the attention of researchers, especially in view of the potential industrial applications. The basic characteristics of the interaction of

Strategy to discover full-length amyloid-beta peptide ligands using high-efficiency microarray technology

• Clelia Galati,
• Natalia Spinella,
• Lucio Renna,
• Danilo Milardi,
• Francesco Attanasio,
• Michele Francesco Maria Sciacca and
• Corrado Bongiorno

Beilstein J. Nanotechnol. 2017, 8, 2446–2453, doi:10.3762/bjnano.8.243

• the blocking process or differ from the fluorescence background level measured on the reference HESs. This result suggests that the silanization process does not critically modify optical properties of the HESs and the interference phenomena responsible for the fluorescence enhancement may still be

Au nanostructure fabrication by pulsed laser deposition in open air: Influence of the deposition geometry

• Rumen G. Nikov,
• Anna Og. Dikovska,
• Nikolay N. Nedyalkov,
• Georgi V. Avdeev and
• Petar A. Atanasov

Beilstein J. Nanotechnol. 2017, 8, 2438–2445, doi:10.3762/bjnano.8.242

• an AXIS Supra electron spectrometer (Kratos Analytical Ltd.). The thickness of the samples was measured using an optical profilometer (Zeta Instruments). The optical properties of the structures produced were estimated based on the transmission spectra taken using an optical spectrometer (Ocean

• observed. The lowest transmission of the sample is due to the highest thickness of the structure formed. Therefore, under the conditions described, the most efficient deposition of material is realized by using the on-axis configuration. It should be mentioned that the optical properties of the

• properties are defined by the collective effects (as multiple scattering and plasmon coupling) of an electromagnetic field interacting with nanoparticle ensembles. This leads to a broadening of the resonance band, where the optical properties of a single nanoparticle are not expressed. To examine the

Optical contrast and refractive index of natural van der Waals heterostructure nanosheets of franckeite

• Patricia Gant,
• Foad Ghasemi,
• David Maeso,
• Carmen Munuera,
• Elena López-Elvira,
• Riccardo Frisenda,
• David Pérez De Lara,
• Gabino Rubio-Bollinger,
• Mar Garcia-Hernandez and
• Andres Castellanos-Gomez

Beilstein J. Nanotechnol. 2017, 8, 2357–2362, doi:10.3762/bjnano.8.235

• values because they are the most common SiO2 thicknesses in the research of graphene and other 2D materials. Prior to the study of the optical properties of the franckeite nanosheets, we experimentally verify the thickness of the SiO2 capping layers of each employed substrate by means of reflectance

• available in the literature yet and it results crucial to further analysis of the optical properties of a material. For example, knowing the refractive index of a 2D material allows one to determine the substrate that optimizes its optical identification. This is done by calculating the optical contrast of

• thickness-dependent optical contrast also allows us to determine the refractive index of franckeite in the visible range of the spectrum (to our knowledge this physical property was not reported in the literature yet) and therefore this work can be a starting point for further studies focused on the optical

Photobleaching of YOYO-1 in super-resolution single DNA fluorescence imaging

• Joseph R. Pyle and
• Jixin Chen

Beilstein J. Nanotechnol. 2017, 8, 2296–2306, doi:10.3762/bjnano.8.229

• ], DNA protein studies [6][7], and optical mapping [8][9][10]. YOYO-1 is a common dye chosen for these studies due to its favorable optical properties. YOYO-1 has a high extinction coefficient of 105 M−1 cm−1 [11] and strongly binds to DNA (binding constant 108–109 M−1) [12] with little sequence

Ta₂N₃ nanocrystals grown in Al₂O₃ thin layers

• Krešimir Salamon,
• Maja Buljan,
• Iva Šarić,
• Mladen Petravić and
• Sigrid Bernstorff

Beilstein J. Nanotechnol. 2017, 8, 2162–2170, doi:10.3762/bjnano.8.215

• generic procedure to realize highly tunable and designable optical properties of thin films containing transition-metal nitride nanocrystals. Keywords: nanocomposites; multilayers; refractory plasmonics; self-assembly; Ta2N3 nanoparticles; Introduction Metallic nanoparticles (NPs) can confine visible

• isolated nitride NPs within thin dielectric layers. An emphasis is placed here on the control of size and spatial arrangement of NPs, which should then ensure the desired optical properties. This is achieved by using reactive magnetron sputtering and the deposition procedure we already used for the self

• the geometrical parameters, on the structure configuration and on the surrounding media of the nanostructures. By using the ML deposition procedure and annealing, we have demonstrated in this work a potential strategy to accomplish highly tunable and designable optical properties of thin films

Substrate and Mg doping effects in GaAs nanowires

• Perumal Kannappan,
• Nabiha Ben Sedrine,
• Jennifer P. Teixeira,
• Maria R. Soares,
• Bruno P. Falcão,
• Maria R. Correia,
• Nestor Cifuentes,
• Emilson R. Viana,
• Marcus V. B. Moreira,
• Geraldo M. Ribeiro,
• Alfredo G. de Oliveira,
• Juan C. González and
• Joaquim P. Leitão

Beilstein J. Nanotechnol. 2017, 8, 2126–2138, doi:10.3762/bjnano.8.212

• Abstract Mg doping of GaAs nanowires has been established as a viable alternative to Be doping in order to achieve p-type electrical conductivity. Although reports on the optical properties are available, few reports exist about the physical properties of intermediate-to-high Mg doping in GaAs nanowires

• properties of intermediate-to-high Mg doping levels are scarce in the literature, with more relevance placed on the optical properties. The envisaged applications of GaAs nanowires depend on the use of substrates with different compositions and orientations. The epitaxial growth of GaAs on Si substrates is

• ) substrates, with the same nominal Mg doping level. A thorough investigation of the morphological, structural, electrical and optical properties of the nanowires is presented. The X-ray diffraction (XRD) measurements suggest a polytypic structure. Electrical measurements performed on individual nanowire back

Synthesis and characterization of noble metal–titania core–shell nanostructures with tunable shell thickness

• Bartosz Bartosewicz,
• Marta Michalska-Domańska,
• Malwina Liszewska,
• Dariusz Zasada and
• Bartłomiej J. Jankiewicz

Beilstein J. Nanotechnol. 2017, 8, 2083–2093, doi:10.3762/bjnano.8.208

• ). Their sizes and shell thicknesses were determined using tunable resistive pulse sensing (TRPS) technique. The optical properties of the synthesized structures were characterized using UV–vis spectroscopy. Ag@TiO2 and Au@TiO2 structures with shell thickness in the range of ≈40–70 nm and 90 nm, for the Ag

• tunable optical properties depending on the ratio of core radius and shell thickness are an excellent example of such structures [3][4]. The CSNs, with either a silica core or shell, have found many applications due to their useful properties, including surface enhanced spectroscopy or cancer therapy [4

• cheaper. More importantly, TRPS measurements are independent of particle density and optical properties such as particle labelling or refractive index [63][64][65]. In fact, it is the only technique among more common and cheaper ones which allows such valuable statistical data to be obtained in the case