Bright fluorescent silica-nanoparticle probes for high-resolution STED and confocal microscopy

• Isabella Tavernaro,
• Christian Cavelius,
• Henrike Peuschel and
• Annette Kraegeloh

Beilstein J. Nanotechnol. 2017, 8, 1283–1296, doi:10.3762/bjnano.8.130

• methods. For this purpose different sizes of Atto647N-doped silica nanoparticles were synthesised following either the method of Stöber [36] or the C-dots method [42]. Both methods utilise ammonia as a catalyst, which has a large influence on the dimension and morphology of the obtained silica

• nanoparticles. Indeed, it is well known that the particle size increases with an increase in ammonia concentration [53][54]. The use of ammonia could be a major limitation for dyes, which are sensitive to high-alkaline pH values. Another drawback of both methods is a broader particle size distribution (Table 2

• /ammonia mixture (0.41 mL/23.57 mL/0.50 mL) directly before the corresponding amount of TEOS. The reaction mixture was stirred for 2 d at room temperature. To gain larger dyed silica nanoparticles (d = 60 nm) the same amount of dye was added to the changed ratio of TEOS (1.05 mL, 4.7 mmol) and the water

Characterization of ferrite nanoparticles for preparation of biocomposites

• Urszula Klekotka,
• Magdalena Rogowska,
• Dariusz Satuła and
• Beata Kalska-Szostko

Beilstein J. Nanotechnol. 2017, 8, 1257–1265, doi:10.3762/bjnano.8.127

• ), Mn (Mn0.5Fe2.5O4) and Ni (Ni0.5Fe2.5O4) were prepared. The synthesis of these materials was done by the modification of Massart’s method [33]. This is based on the co-precipitation of (0.81 g) Fe(III) and (0.29 g) Fe(II) chlorides in 0.5% ammonia aqueous solution at a temperature of 80 °C under Ar

Preparation of thick silica coatings on carbon fibers with fine-structured silica nanotubes induced by a self-assembly process

• Benjamin Baumgärtner,
• Hendrik Möller,
• Thomas Neumann and
• Dirk Volkmer

Beilstein J. Nanotechnol. 2017, 8, 1145–1155, doi:10.3762/bjnano.8.116

• methanol, dried under ambient conditions and subsequently dissolved in water by neutralizing with 25 wt % aqueous ammonia solution. The clear polymer solution was transferred into dialysis tubing (Aldrich, cellulose membrane, typical molecular weight cut-off: 3500 kDa) and the dialysis was carried out

• against 5 M ammonia solution for 3 days with 6 changes of the ammonia solution. The obtained white crystalline LPEI was washed with water and acetone and dried in a desiccator over silica gel under vacuum. The remaining water content is about 20 wt % as determined by thermogravimetric analysis

Hierarchically structured nanoporous carbon tubes for high pressure carbon dioxide adsorption

• Julia Patzsch,
• Deepu J. Babu and
• Jörg J. Schneider

Beilstein J. Nanotechnol. 2017, 8, 1135–1144, doi:10.3762/bjnano.8.115

• material. Experimental Materials Polystyrene (PS, pro-plast from BASF), tetraethylorthosilicate (TEOS, ABCR), ammonia (NH3, Grüssing), dimethylformamide (DMF, Merck), tetrahydrofuran (THF, Merck), and ethanol (EtOH, Brenntag) were used as received without further purification. Synthesis of polystyrene

CVD transfer-free graphene for sensing applications

• Chiara Schiattarella,
• Sten Vollebregt,
• Tiziana Polichetti,
• Brigida Alfano,
• Ettore Massera,
• Maria Lucia Miglietta,
• Girolamo Di Francia and
• Pasqualina Maria Sarro

Beilstein J. Nanotechnol. 2017, 8, 1015–1022, doi:10.3762/bjnano.8.102

• straightforward integration in electronic devices. Keywords: ammonia; chemiresistors; CMOS-compatible process; graphene; nitrogen dioxide; transfer-free growth; Introduction Due to its extraordinary electronic, chemical, mechanical, thermal and optical properties, graphene has been defined as the “wonder

• have been exposed to NH3. Even in this case both chemiresistors exhibit a comparable percentage variation of the conductance, as well as similar kinetics (Figure 4). Because ammonia is an electron-donor analyte, the conductance show a decrease, further confirming the p-type nature of the synthesized

Investigation of growth dynamics of carbon nanotubes

• Marianna V. Kharlamova

Beilstein J. Nanotechnol. 2017, 8, 826–856, doi:10.3762/bjnano.8.85

• floating-catalyst CVD process with a use of ferrocene as catalyst precursor and a small amount of ammonia. Over 90% of SWCNTs had near-armchair structure. It was suggested that NH3, which is a strong etchant, selectively etched off SWCNTs with small chiral angles due to their higher reactivity and lower

Synthesis of graphene–transition metal oxide hybrid nanoparticles and their application in various fields

• Arpita Jana,
• Elke Scheer and
• Sebastian Polarz

Beilstein J. Nanotechnol. 2017, 8, 688–714, doi:10.3762/bjnano.8.74

• lithium storage upon cycling contribute to an enhanced specific capacity [142]. N-doped MnO–graphene prepared by a simple hydrothermal method followed by a heat treatment under ammonia atmosphere, shows a higher capacity and cycle life due to the unique N-doped nanostructure and the efficient mixing with

Gas sensing properties of MWCNT layers electrochemically decorated with Au and Pd nanoparticles

• Elena Dilonardo,
• Michele Penza,
• Marco Alvisi,
• Riccardo Rossi,
• Gennaro Cassano,
• Cinzia Di Franco,
• Francesco Palmisano,
• Luisa Torsi and
• Nicola Cioffi

Beilstein J. Nanotechnol. 2017, 8, 592–603, doi:10.3762/bjnano.8.64

• this case, to explain the higher sensitivity of Pd-functionalized MWCNTs in the detection of ammonia and small hydrocarbon gas molecules like butane [54]. According to [54][55], when present on the MWCNT surface, Pd NPs form a weakly bonded complex between Pd atoms and adsorbed oxygen molecules at room

Graphene functionalised by laser-ablated V₂O₅ for a highly sensitive NH₃ sensor

• Margus Kodu,
• Artjom Berholts,
• Tauno Kahro,
• Mati Kook,
• Peeter Ritslaid,
• Helina Seemen,
• Tea Avarmaa,
• Harry Alles and
• Raivo Jaaniso

Beilstein J. Nanotechnol. 2017, 8, 571–578, doi:10.3762/bjnano.8.61

• on graphene with average thickness of ≈0.6 nm. From Raman spectroscopy, it was concluded that the PLD process also induced defects in graphene. Compared to unmodified graphene, the obtained chemiresistive sensor showed considerable improvement of sensing ammonia at room temperature. In addition, the

• between deposited V2O5 and graphene. Keywords: ammonia; electric conductivity; gas sensor; graphene; pulsed laser deposition; UV light activation; vanadium(V) oxide; Introduction Graphene, being a thin (semi)conducting material, is a promising gas sensing system. Highly sensitive response, down to

• gases, such as ammonia. Vanadium oxide based films and nanostructured layers have been previously synthesised for gas sensing applications by various methods [11], including pulsed laser deposition (PLD) [12]. PLD is a highly versatile method for relatively well-controlled preparation of thin films, and

Fiber optic sensors based on hybrid phenyl-silica xerogel films to detect n-hexane: determination of the isosteric enthalpy of adsorption

• Jesús C. Echeverría,
• Ignacio Calleja,
• Paula Moriones and
• Julián J. Garrido

Beilstein J. Nanotechnol. 2017, 8, 475–484, doi:10.3762/bjnano.8.51

• ammonia were supplied by Merck (Darmstadt, Germany). Silicon precursors with purity greater than 98% were obtained from Sigma-Aldrich (Steinheim, Germany). All chemicals were used without further purification. Water was deionized and purified with a Milli-Q system (model 185, Millipore, Mosheim, France

Tailoring bifunctional hybrid organic–inorganic nanoadsorbents by the choice of functional layer composition probed by adsorption of Cu²⁺ ions

• Veronika V. Tomina,
• Inna V. Melnyk,
• Yuriy L. Zub,
• Aivaras Kareiva,
• Miroslava Vaclavikova,
• Gulaim A. Seisenbaeva and
• Vadim G. Kessler

Beilstein J. Nanotechnol. 2017, 8, 334–347, doi:10.3762/bjnano.8.36

• into account the already developed principles of the production of APTES-derived materials [48][49]. The particles are generally smaller when higher TEOS/APTES ratios are applied [31]. They are less coalesced in the presence of higher ammonia content because of a stronger negative charging of the

• growing entities, which is especially important for highly hydrophobic materials that can otherwise form gels separating from solutions [50][51][52]. The most efficient way to keep the aminopropyl groups on the surface is to add TEOS after the APTES and, especially, to slightly increase the ammonia

• –ammonia complexes are well known. They also correlate well with the data obtained by some other physical methods (e.g., electron spectroscopy and EPR) as is traced in detail in [53]. Comparing the values of the sorption rate constants for monofunctional and amino/methyl samples, we can conclude, that the

Nitrogen-doped twisted graphene grown on copper by atmospheric pressure CVD from a decane precursor

• Ivan V. Komissarov,
• Nikolai G. Kovalchuk,
• Vladimir A. Labunov,
• Ksenia V. Girel,
• Olga V. Korolik,
• Mikhail S. Tivanov,
• Algirdas Lazauskas,
• Mindaugas Andrulevičius,
• Tomas Tamulevičius,
• Viktoras Grigaliūnas,
• Šarunas Meškinis,
• Sigitas Tamulevičius and
• Serghej L. Prischepa

Beilstein J. Nanotechnol. 2017, 8, 145–158, doi:10.3762/bjnano.8.15

• edges [13]. Finally, we turn to the problem of nitrogen incorporation into graphene. Nitrogen can be incorporated into graphene sheet (i) in situ, using ammonia as a component of the gas carrier mixture [43] or with nitrogen containing precursors [60][61] and (ii) by post-treatment, e.g., by treatment

• in ammonia plasma [62] or N-ion irradiation [63]. To the best of our knowledge, there is only one article where N2 gas was used as the nitrogen source during the CVD growth [64]. In our opinion, the main difficulties in using N2 gas as a nitrogen source arises from the fact that nitrogen molecule

From iron coordination compounds to metal oxide nanoparticles

• Mihail Iacob,
• Carmen Racles,
• Codrin Tugui,
• George Stiubianu,
• Adrian Bele,
• Liviu Sacarescu,
• Daniel Timpu and
• Maria Cazacu

Beilstein J. Nanotechnol. 2016, 7, 2074–2087, doi:10.3762/bjnano.7.198

• for NPM1 the pH of the reaction system was adjusted to 11. The sample NPM0 was obtained by adding ammonia water to the aqueous solution of FeAc2, without any additional operations (stirring, heating, etc.) and used as a control. The NPM1 and NPM2 samples were obtained by adding ammonia water to an

• , (0.5 g in each case) in a furnace up to 600 °C in air (heating rate 50 °C/min) and maintained at this temperature for 5 h. Preparation of iron oxide nanoparticles under microwave irradiation (NPM series). FeAc2 (0.3 mmol) was dissolved in 1 mL of distilled water, after which 2 mL of ammonia water (25

• ultrasonicated for 1 min at 100 °C, then 40 mL of ammonia water (25%) were added to the solution. The ultrasonication time was 10 min for sample NPU1, and 30 min for NPU2. TEM images and particle size distribution histograms of NPT1a (a,c) and NPT1b (b,d). The TEM images (a,c) and the histogram of the particle

Solvent-mediated conductance increase of dodecanethiol-stabilized gold nanoparticle monolayers

• Patrick A. Reissner,
• Jean-Nicolas Tisserant,
• Antoni Sánchez-Ferrer,
• Raffaele Mezzenga and
• Andreas Stemmer

Beilstein J. Nanotechnol. 2016, 7, 2057–2064, doi:10.3762/bjnano.7.196

• nitrogen prior to immersion. For OPE/THF and TPT/EtOH immersion the molecular concentration was 1 mM. In the case of OPE, the acetyl protecting group was removed by addition of 20 µL ammonia (30%) in 3 mL solution while bubbling with nitrogen. The samples were immersed upside down. After immersion the

A dioxaborine cyanine dye as a photoluminescence probe for sensing carbon nanotubes

• Mohammed Al Araimi,
• Petro Lutsyk,
• Anatoly Verbitsky,
• Yuri Piryatinski,
• Mykola Shandura and
• Aleksey Rozhin

Beilstein J. Nanotechnol. 2016, 7, 1991–1999, doi:10.3762/bjnano.7.190

• probes for amines and ammonia [14][15][16]. Optical properties (absorption and PL) of monomeric and dimeric forms of DOB-719 were reported in [16] showing that there is a weak interaction of SWNTs with DOB-719. The novelty of the present study is an elucidation of the interaction of the dye with the

Facile fabrication of luminescent organic dots by thermolysis of citric acid in urea melt, and their use for cell staining and polyelectrolyte microcapsule labelling

• Nadezhda M. Zholobak,
• Anton L. Popov,
• Alexander B. Shcherbakov,
• Nelly R. Popova,
• Mykhailo M. Guzyk,
• Valeriy P. Antonovich,
• Alla V. Yegorova,
• Yuliya V. Scrypynets,
• Inna I. Leonenko,
• Alexander Ye. Baranchikov and
• Vladimir K. Ivanov

Beilstein J. Nanotechnol. 2016, 7, 1905–1917, doi:10.3762/bjnano.7.182

• spectral properties Citric acid reacts with ammonia in a molar ratio of 1:3 to form triammonium citrate, and with urea in a molar ratio of 1:1 [37] to form urea citrate. Thermolysis of ammonium citrate or urea citrate leads to formation of the luminescent O-dots, proceeding readily and at moderate

• non-linear (Figure 2, right). More details on the absorption, excitation and emission spectra of the samples are presented in Supporting Information File 1, Figures S5–S10. Upon heating, decomposition and release of gaseous products such as water, ammonia, carbon dioxide took place. Useful indicators

• acid and ammonia [41][42] released in the course of urea decomposition. It was found that the heating of pure ammonium citrazinate at 160 °C for 120 min did not affect its absorption and emission spectra. Conversely, heating ammonium citrazinate in the urea melt led to O-dots formation (Supporting

Role of RGO support and irradiation source on the photocatalytic activity of CdS–ZnO semiconductor nanostructures

• Suneel Kumar,
• Rahul Sharma,
• Vipul Sharma,
• Gurunarayanan Harith,
• Vaidyanathan Sivakumar and
• Venkata Krishnan

Beilstein J. Nanotechnol. 2016, 7, 1684–1697, doi:10.3762/bjnano.7.161

• permanganate (KMnO4) and hydrogen peroxide (H2O2) were purchased from Merck. Zinc chloride (ZnCl2), sodium hydroxide (NaOH), cadmium acetate dihydrate (Cd(OOCCH3)2·2H2O), sodium sulfide (Na2S), ammonia solution and methyl orange were also supplied by Merck. Polyvinyl pyrrolidone (PVP) used in synthesis was

• adding ammonia solution. The resultant solution was refluxed for about 1 h at 70 °C. Upon completion of the reaction, the product was washed with deionized water and ethanol thrice and finally yellow colored CdS NP were formed after drying in an oven at 80 °C for 2 h. Synthesis of CdS–ZnO binary

• nanocomposite CdS–ZnO binary nanocomposite was prepared by employing a reported hydrothermal strategy [39]. In short, 0.2 M ZnCl2 was dispersed in 40 mL deionized water, followed by the addition of 0.5 M NaOH solution dropwise with continuous stirring. Aqueous ammonia was added to maintain the pH value around 8

Graphene-enhanced plasmonic nanohole arrays for environmental sensing in aqueous samples

• Christa Genslein,
• Peter Hausler,
• Eva-Maria Kirchner,
• Rudolf Bierl,
• Antje J. Baeumner and
• Thomas Hirsch

Beilstein J. Nanotechnol. 2016, 7, 1564–1573, doi:10.3762/bjnano.7.150

• . Experimental Nanohole array fabrication All substrates are based on glass slides (20 × 20 mm2) of F1-Type with a refractive index of 1.61 (Mivitec GmbH, Sinzing, Germany). All glass slides were cleaned in piranha solution for 90 min and in a mixture of water, ammonia and hydrogen peroxide at a 5:1:1 (v/v/v

Viability and proliferation of endothelial cells upon exposure to GaN nanoparticles

• Tudor Braniste,
• Ion Tiginyanu,
• Tibor Horvath,
• Simion Raevschi,
• Serghei Cebotari,
• Marco Lux,
• Axel Haverich and
• Andres Hilfiker

Beilstein J. Nanotechnol. 2016, 7, 1330–1337, doi:10.3762/bjnano.7.124

• epitaxy (HVPE) in two stages, as previously described [29]. Metallic gallium, ammonia (NH3) gas, hydrogen chloride (HCl) gas, and hydrogen (H2) were used as source materials and carrier gases. In the source zone, GaCl was formed as a result of chemical reactions between gaseous HCl and liquid Ga. GaCl and

Ammonia gas sensors based on In₂O₃/PANI hetero-nanofibers operating at room temperature

• Qingxin Nie,
• Zengyuan Pang,
• Hangyi Lu,
• Yibing Cai and
• Qufu Wei

Beilstein J. Nanotechnol. 2016, 7, 1312–1321, doi:10.3762/bjnano.7.122

• PANI influences the sensing performance of the In2O3/PANI composite nanofibers. In this paper, In2O3/PANI composite nanofibers with a mass ratio of 1:2 exhibited the highest response values, excellent selectivity, good repeatability and reversibility. Keywords: ammonia (NH3); electrospinning; gas

• pollution. Ammonia (NH3), as a highly toxic gas, can be emitted by natural and industrial sources and threaten human health [2][3][4]. NH3 at concentrations of 50 ppm may irritate the human respiratory system, skin and eyes [4]. Higher concentrations of NH3 will cause blindness, seizures, lung disease and

• even death [5][6][7]. So, there is an urgent need to develop a kind of gas sensor with high sensitivity and selectivity to detect NH3 at room temperature. Metal oxide semiconductors can be applied as sensing materials for monitoring NH3. Ammonia sensors based on In2O3 [8], TiO2 [9], SnO2 [10], ZnO [11

Mesoporous hollow carbon spheres for lithium–sulfur batteries: distribution of sulfur and electrochemical performance

• Anika C. Juhl,
• Artur Schneider,
• Boris Ufer,
• Torsten Brezesinski,
• Jürgen Janek and
• Michael Fröba

Beilstein J. Nanotechnol. 2016, 7, 1229–1240, doi:10.3762/bjnano.7.114

• methods in a two-step procedure [33][34]. For synthesis of the core, 536 mL of ethanol were mixed with 45 mL of aqueous ammonia (32%) and 6.8 mL of deionized water. After stirring for 30 min, 24 mL of tetraethyl orthosilicate (TEOS) were added and the mixture was stirred at room temperature for 18 h. The

Reasons and remedies for the agglomeration of multilayered graphene and carbon nanotubes in polymers

• Rasheed Atif and
• Fawad Inam

Beilstein J. Nanotechnol. 2016, 7, 1174–1196, doi:10.3762/bjnano.7.109

• introduction of heteroatoms in SWNTs can lead to novel properties. Heating may remove the attached functionalized groups. The functionalized SWNTs can be dissolved in organic solvents up to about 100 mg/L. The functionalization of SWNTs in liquid ammonia by reductive alkylation using lithium and alkyl halides

Phenalenyl-based mononuclear dysprosium complexes

• Yanhua Lan,
• Andrea Magri,
• Olaf Fuhr and
• Mario Ruben

Beilstein J. Nanotechnol. 2016, 7, 995–1009, doi:10.3762/bjnano.7.92

• ’ was characterized confirming its thermal stability. Results and Discussion Synthesis Van Deun et al. [23][24] synthesized 1:3 metal-to-ligand complexes using ammonia as a base and 1:4 metal-to-ligand complexes using the stronger base NaOH. In addition, phenalenyl-based europium and gadolinium

• nonanuclear complexes [26] were obtained by using (Et)3N as base in a 1:1.8 metal-to-ligand ratio. The synthetic procedures reported in our work are illustrated in Scheme 1. Instead of ammonia or NaOH as a base [23][24], we used NaH or diisopropyl amine to deprotonate the HPLN ligand. In order to obtain

Dielectrophoresis of gold nanoparticles conjugated to DNA origami structures

• Anja Henning-Knechtel,
• Matthew Wiens,
• Mathias Lakatos,
• Andreas Heerwig,
• Frieder Ostermaier,
• Nora Haufe and
• Michael Mertig

Beilstein J. Nanotechnol. 2016, 7, 948–956, doi:10.3762/bjnano.7.87

• peroxide (30 wt % in water; Merck), ammonia solution (25 wt % in water; Merck) and ddH2O in the ratio 1:1:5] and rinsed with ddH2O. Then, such a glass slide was placed in an inverted optical microscope (Axiovert 200M, Carl Zeiss MicroImaging) equipped with a 100×/1.45 numerical aperture oil immersion

Synthesis and applications of carbon nanomaterials for energy generation and storage

• Marco Notarianni,
• Jinzhang Liu,
• Kristy Vernon and
• Nunzio Motta

Beilstein J. Nanotechnol. 2016, 7, 149–196, doi:10.3762/bjnano.7.17

• can help to decrease the required annealing temperature to 450 °C and still give a high C/O ratio of ≈15, as was demonstrate by Wu et al. [120]. Li et al. [121] instead used a mixture of ammonia and argon (2 Torr, NH3/Ar (10% NH3), 500 °C) to produce good quality, doped rGO. The drawbacks of thermal