Fixation mechanisms of nanoparticles on substrates by electron beam irradiation

• Daichi Morioka,
• Tomohiro Nose,
• Taiki Chikuta,
• Kazutaka Mitsuishi and
• Masayuki Shimojo

Beilstein J. Nanotechnol. 2017, 8, 1523–1529, doi:10.3762/bjnano.8.153

• nm, was deposited by sputtering on the same Si substrate as used for Au nanoparticles. The surface of the Au-deposited substrate was covered with a monolayer of amino-undecanethiol. Then, the substrate was immersed in a colloidal silica (surface-modified with –COOH) solution for 24 h to arrange

Assembly of metallic nanoparticle arrays on glass via nanoimprinting and thin-film dewetting

• Sun-Kyu Lee,
• Sori Hwang,
• Yoon-Kee Kim and
• Yong-Jun Oh

Beilstein J. Nanotechnol. 2017, 8, 1049–1055, doi:10.3762/bjnano.8.106

• on the glass (arrowed). Figure 6 shows SEM images of the regions with Ag and Au nanoparticles. The initial film thickness and dewetting temperatures determined the shape and distribution of the dewetted particles on glass. In Figure 6a,b, small nanoparticles clustered around the pits as an 8 nm thick

• at 500 °C. Black arrows in images f and h indicate surface cracks formed in imprinted sol–gel silica. Size distribution of (a–c) Ag and (d) Au particles formed at different dewetting temperatures on imprinted sol–gel silica, and (e) Au particles formed on the silicon master mold. (a) SEM image of Au

• nanoparticles dewetted on the silicon master mold by annealing at 500 °C and (b) a comparison of XRD spectra for Au particle arrays formed on the imprinted sol–gel silica in Figure 6h and silicon master mold in Figure 8a.

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

• nanostructure. Keywords: Au–DNA nanocomposites; enhanced fluorescence emission; metal-ion detection; Mg2+ ion detection; Introduction The interactions between Au nanoparticles (AuNPs) and DNA are essential to classify and expand upon, given the potential applications for NP–DNA complexes such as gene therapy

• ]. Also, in DNA, the specific base pairing and the availability of free hydroxyl and phosphate groups have been used to build the structured assembly of particles [4]. DNA-functionalized Au nanoparticles are often applied as nanoscale building blocks in assembly strategies, nanotherapeutics and antisense

• Tanushree Basu Khyati Rana Niranjan Das Bonamali Pal School of Chemistry and Biochemistry, Thapar University, Patiala 147004, Punjab, India Department of Biotechnology, Thapar University, Patiala 147004, Punjab, India 10.3762/bjnano.8.79 Abstract The biophysical properties of DNA-modified Au

Electric field induced structural colour tuning of a silver/titanium dioxide nanoparticle one-dimensional photonic crystal

• Eduardo Aluicio-Sarduy,
• Simone Callegari,
• Diana Gisell Figueroa del Valle,
• Andrea Desii,
• Ilka Kriegel and
• Francesco Scotognella

Beilstein J. Nanotechnol. 2016, 7, 1404–1410, doi:10.3762/bjnano.7.131

• effect of applied voltage on thin films of Ag would be required for an exact evaluation of the effect on the Drude parameters and a more precise extraction of the number of carriers injected. Nevertheless, our estimation is in good agreement with results on the electrochemical doping of Au nanoparticles

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

• living cells and different types of nanoparticles of specific shape, surface charge, and chemical composition [4]. For example, elongated, rod-like gold (Au) nanoparticles affect the viability of endothelial cells more than spherical ones, which have better biocompatibility [5]. However, multiwalled

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

• nanoparticles [26][27]. Birojou et al. have also observed that in the case of nonfunctionalized graphene decorated by gold nanoparticles via electrostatic interactions, the defect sites on the graphene are preferentially decorated by the Au nanoparticles with an increase in the sp2 hybridization of graphene in

NO gas sensing at room temperature using single titanium oxide nanodot sensors created by atomic force microscopy nanolithography

• Li-Yang Hong and
• Heh-Nan Lin

Beilstein J. Nanotechnol. 2016, 7, 1044–1051, doi:10.3762/bjnano.7.97

• with these reported results. Furthermore, it can be seen that the performances of metal oxides with Au are much better those of pure metal oxides, which is due to the plasmonic effect [18][20]. It is expected that the present ND sensors can be improved in a similar fashion, e.g., by creating Au

• nanoparticles on the ND surface. Conclusion In summary, single titanium oxide ND sensors are realized by AFM nanolithography and used for NO gas sensing. A Ti NW is generated first by AFM nanomachining and a titanium oxide ND is then produced in the NW by AFM nano-oxidation. With contact electrodes, a resistive

Direct formation of gold nanorods on surfaces using polymer-immobilised gold seeds

• Majid K. Abyaneh,
• Pietro Parisse and
• Loredana Casalis

Beilstein J. Nanotechnol. 2016, 7, 809–816, doi:10.3762/bjnano.7.72

• polymer matrix, and formed Au nanoparticles can be observed on top of them. This means that there are few blisters formed on the polymer surface during UV irradiation. Figure 3 shows AFM images for low- and high-Mw PMMA matrices with 60 wt % gold salt which are denominated as P1-60 and P2-60, respectively

Fabrication and properties of luminescence polymer composites with erbium/ytterbium oxides and gold nanoparticles

• Julia A. Burunkova,
• Ihor Yu. Denisiuk,
• Dmitri I. Zhuk,
• Lajos Daroczi,
• Attila Csik,
• István Csarnovics and
• Sándor Kokenyesi

Beilstein J. Nanotechnol. 2016, 7, 630–636, doi:10.3762/bjnano.7.55

• use of SiO2 nanoparticles increases the reaction yield of this technology process. Polymer nanocomposites containing Er/Yb oxide nanoparticles as well as SiO2 nanoparticles and Au nanoparticles were created. SiO2 nanoparticles compatible with the selected polymer matrix can be used to ensure a uniform

Evaluation of gas-sensing properties of ZnO nanostructures electrochemically doped with Au nanophases

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

Beilstein J. Nanotechnol. 2016, 7, 22–31, doi:10.3762/bjnano.7.3

• washed with distilled water until complete elimination of chlorine ions in the liquid phase and then dehydrated at 120 °C for 2 h to maintain hydroxy (–OH) groups on the oxide surface, that are ideal to stabilize Au nanoparticles during the electrosynthesis [43][44][45][46]. Electrochemical decoration of

• rpm to separate unsupported colloidal Au nanoparticles from the heavier Au@ZnO nanocomposite. After separation, Au@ZnO were thermally annealed at 300 or 550 °C for 2 h in air to study the effect of thermal annealing on the structural stability of Au NPs [45], and of ZnO [44][49], and on the surface

Self-organization of gold nanoparticles on silanated surfaces

• Htet H. Kyaw,
• Salim H. Al-Harthi,
• Azzouz Sellai and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2015, 6, 2345–2353, doi:10.3762/bjnano.6.242

• silanes (Figure 2, type III). Surface morphology analysis of Au nanoparticles deposited on APTES-functionalized glass substrates The surface morphology of AuNPs deposited on self-assembled APTES-functionalized glass substrates (functionalization time of 24 h) are shown in Figure 4. The surface morphology

Electrochemical behavior of polypyrrol/AuNP composites deposited by different electrochemical methods: sensing properties towards catechol

• Celia García-Hernández,
• Cristina García-Cabezón,
• Cristina Medina-Plaza,
• Fernando Martín-Pedrosa,
• Yolanda Blanco,
• José Antonio de Saja and
• María Luz Rodríguez-Méndez

Beilstein J. Nanotechnol. 2015, 6, 2052–2061, doi:10.3762/bjnano.6.209

• synergy between Pt and Au nanoparticles gave rise to lower LODs. In turn, stainless steel can be used as the substrate in the absence of KCl, with a LOD only slightly higher than those obtained in sensors deposited on Pt, but at a lower cost. Experimental Reagents and solutions All experiments were

Synthesis, characterization and in vitro biocompatibility study of Au/TMC/Fe₃O₄ nanocomposites as a promising, nontoxic system for biomedical applications

• Hanieh Shirazi,
• Maryam Daneshpour,
• Soheila Kashanian and
• Kobra Omidfar

Beilstein J. Nanotechnol. 2015, 6, 1677–1689, doi:10.3762/bjnano.6.170

• Institute, Tehran University of Medical Sciences, Tehran, Iran, Faculty of Chemistry, Nanoscience and Nanotechnology Research Center, Razi University, Kermanshah, Iran 10.3762/bjnano.6.170 Abstract The unique properties and applications of iron oxide and Au nanoparticles have motivated researchers to

• . Moreover, the results of the MTT assay showed no significant cytotoxicity effect when the Au/TMC/Fe3O4 nanocomposites were applied in vitro. These TMC-containing magnetic nanoparticles are well-coated by Au nanoparticles and have good biocompatibility and can thus play the role of a platform or a label in

• various fields of application, especially the biomedical sciences and biosensors. Keywords: Au/polymer/Fe3O4 nanocomposites; Au nanoparticles; cell viability; magnetic nanoparticles; N-trimethyl chitosan; Introduction Nanotechnology is the science of the fabrication of novel materials, devices and

Possibilities and limitations of advanced transmission electron microscopy for carbon-based nanomaterials

• Xiaoxing Ke,
• Carla Bittencourt and
• Gustaaf Van Tendeloo

Beilstein J. Nanotechnol. 2015, 6, 1541–1557, doi:10.3762/bjnano.6.158

• reported that the deformation of Au-contacted CNT walls is more prominent compared to Pd-contacted CNT walls (not shwon), which could be associated to higher wettability of Pd over Au nanoparticles on one hand. On the other hand, a deformation mechanism through elastic strain relaxation is also proposed

Synthesis, characterization and in vitro effects of 7 nm alloyed silver–gold nanoparticles

• Simon Ristig,
• Svitlana Chernousova,
• Wolfgang Meyer-Zaika and
• Matthias Epple

Beilstein J. Nanotechnol. 2015, 6, 1212–1220, doi:10.3762/bjnano.6.124

• nanoparticles were characterized with respect to their physicochemical properties and their in vitro reaction. Results Nanoparticle characterization Alloyed Ag/Au nanoparticles were synthesized similar to the previously reported synthesis of alloyed Ag/Au 50:50 nanoparticles [30]; however, higher amounts of the

• values were close to the theoretical compositions (Table 2). To confirm the alloying of the two metals, UV–vis spectra were recorded for all samples. From the spectra it is possible to gain information about the inner structure of the nanoparticles. In case of alloyed Ag/Au nanoparticles, the plasmon

• presented herein is well suited for the generation of monodisperse, bimetallic, Ag/Au nanoparticles of different molar compositions. The particles can be coated with a polymer shell (e.g., PVP) for enhanced colloidal stability in aqueous medium. The characterization of the nanoparticles using complementary

Improved optical limiting performance of laser-ablation-generated metal nanoparticles due to silica-microsphere-induced local field enhancement

• Zheren Du,
• Lianwei Chen,
• Tsung-Sheng Kao,
• Mengxue Wu and
• Minghui Hong

Beilstein J. Nanotechnol. 2015, 6, 1199–1204, doi:10.3762/bjnano.6.122

• the colloidal solution. The silver nanoparticle diameters range from 20 to 500 nm with maximum at 80 nm. It can be seen that a few Ag nanoparticles have a relatively larger diameter in the range of a few hundred nanometers. Comparing these two types of nanoparticles, the Au nanoparticles have a

• -generated metallic nanoparticles are promising optical limiting materials. Several mechanisms, as discussed in the Introduction, could be responsible for the optical limiting behavior of these materials. Under the illumination of ns laser pulses at 1064 nm, the optical limiting effect of Au nanoparticles

Scanning reflection ion microscopy in a helium ion microscope

• Yuri V. Petrov and
• Oleg F. Vyvenko

Beilstein J. Nanotechnol. 2015, 6, 1125–1137, doi:10.3762/bjnano.6.114

• to be 2.5 nm. These values gave the angle of the beam divergence of approximately 0.5 mrad, which is in a good agreement with the manufacturer’s data. Figure 2 represents the images of a Au on carbon sample that is partially covered by Au nanoparticles in the central part only. As expected, the Au

• imaging modes of Au on carbon. One can see that in both imaging modes there is no noticeable signal level difference between the Au nanoparticles in the central part of the image and the carbon substrate in the upper and the lower parts of the image. This implies that the RI yield at low ion incidence

Patterning technique for gold nanoparticles on substrates using a focused electron beam

• Takahiro Noriki,
• Shogo Abe,
• Kotaro Kajikawa and
• Masayuki Shimojo

Beilstein J. Nanotechnol. 2015, 6, 1010–1015, doi:10.3762/bjnano.6.104

• electron beam irradiation, and finally, the unfixed nanoparticles are removed. Results and Discussion In this technique, the sample was made by implementing the following steps: Step (i): Au nanoparticles are placed on a substrate. Step (ii): Selected nanoparticles are immobilized on the substrate by

• ]. Then, the sample was immersed for 3 h in a colloidal gold solution containing gold particles of 50 nm diameter. Although this method will not produce a two-dimensional close packing of Au nanoparticles, it will result in the relatively uniform distribution of Au nanoparticles. Step (ii): electron beam

Pt- and Pd-decorated MWCNTs for vapour and gas detection at room temperature

• Hamdi Baccar,
• Atef Thamri,
• Pierrick Clément,
• Eduard Llobet and
• Adnane Abdelghani

Beilstein J. Nanotechnol. 2015, 6, 919–927, doi:10.3762/bjnano.6.95

• , recovering the sensor baseline required heating at 150 °C. This heat treatment to regain the sensor baseline was also observed by Mudimela and co-workers when they used vertically aligned carbon nanotubes decorated with sputtered Au nanoparticles to detect nitrogen dioxide [37]. Finally, Clément and co

Palladium nanoparticles anchored to anatase TiO₂ for enhanced surface plasmon resonance-stimulated, visible-light-driven photocatalytic activity

• Kah Hon Leong,
• Hong Ye Chu,
• Shaliza Ibrahim and
• Pichiah Saravanan

Beilstein J. Nanotechnol. 2015, 6, 428–437, doi:10.3762/bjnano.6.43

• plasmonic Au nanoparticles deposited on top of TiO2 [27]. While Mohapatra et al. had synthesized TiO2 nanotubes with palladium (Pd) NPs for the photocatalytic decomposition of azo dyes under sunlight irradiation. Pd/TiO2 nanotubes showed a faster degradation time (150 min) to completely decompose azo dye as

Nanoparticle shapes by using Wulff constructions and first-principles calculations

• Georgios D. Barmparis,
• Zbigniew Lodziana,
• Nuria Lopez and
• Ioannis N. Remediakis

Beilstein J. Nanotechnol. 2015, 6, 361–368, doi:10.3762/bjnano.6.35

• the center of the nanoparticle might not coincide with the symmetry center of the crystal structure. For Au nanoparticles, for example, two different classes of nanoparticles can be found depending on whether the center of the nanoparticle is at an fcc lattice point or at the octahedral site of the

• accommodate a single atom, let alone a unit cell of the (hkl) plane they represent. This leads to shapes for small nanoparticles that are significantly simpler than the Wulff polyhedron. For example, Au nanoparticles with diameter less than 16 nm contain only (111) and (100) surfaces, although the Wulff shape

• contains (111), (332), (100), (211), and (322) [15]. An example of atomistic Wulff construction for relatively large Au nanoparticles is shown in Figure 2. Upon exposure to CO or CH3S radical gas, the nanoparticle changes towards more spherical shapes, in accordance with experiments [58]. Nanoparticles

Comparative evaluation of the impact on endothelial cells induced by different nanoparticle structures and functionalization

• Lisa Landgraf,
• Ines Müller,
• Peter Ernst,
• Miriam Schäfer,
• Christina Rosman,
• Isabel Schick,
• Oskar Köhler,
• Hartmut Oehring,
• Vladimir V. Breus,
• Thomas Basché,
• Carsten Sönnichsen,
• Wolfgang Tremel and
• Ingrid Hilger

Beilstein J. Nanotechnol. 2015, 6, 300–312, doi:10.3762/bjnano.6.28

• positive surface and a small nanoparticle size. Interestingly, in the case of Au-NH2@Fe3O4 and 4 nm sized Au nanoparticles, the rapid uptake into endosomes and lysosomes leads to disturbed membrane integrity and the release of the nanoparticles into the cytoplasm. 4) A comparison of smaller and larger

• with 5µg/mL of spherical gold (Au) nanoparticles (Nanopartz). All nanoparticles are localized in lysosomes and endosomes. Au@Fe3O4 and Fe3O4 are stored in small and clear delineated endosomes and secondary lysosomes (black arrows). White arrows point to damaged intracellular membranes. White arrow

Low-cost plasmonic solar cells prepared by chemical spray pyrolysis

• Erki Kärber,
• Atanas Katerski,
• Ilona Oja Acik,
• Valdek Mikli,
• Arvo Mere,
• Ilmo Sildos and
• Malle Krunks

Beilstein J. Nanotechnol. 2014, 5, 2398–2402, doi:10.3762/bjnano.5.249

• planar ZnO were prepared entirely by chemical spray pyrolysis. Au nanoparticles (Au-NPs) were formed via thermal decomposition of a gold(III) chloride trihydrate (HAuCl4·3H2O) precursor by spraying 2 mmol/L of the aqueous precursor solution onto a substrate held at 260 °C. Current–voltage scans and

• % increase (from 4.6 to 7.5 mA/cm2) of the short-circuit current density was observed when 2.5 mL of the precursor solution was deposited onto the rear side of the solar cell. Keywords: Au nanoparticles; chemical spray pyrolysis; extremely thin absorber; plasmon resonance; solar cell; Introduction The cost

Inorganic Janus particles for biomedical applications

• Isabel Schick,
• Steffen Lorenz,
• Dominik Gehrig,
• Stefan Tenzer,
• Wiebke Storck,
• Karl Fischer,
• Dennis Strand,
• Frédéric Laquai and
• Wolfgang Tremel

Beilstein J. Nanotechnol. 2014, 5, 2346–2362, doi:10.3762/bjnano.5.244

• efficiencies. This influence was mainly ascribed to the enhanced dye absorption by the magnified near-field of Au nanoparticles and the plasmon-enhanced photocurrent generation (Figure 6c) [51]. Synthesis of inorganic Janus particles The synthesis of hetero-nanoparticles requires an even higher degree of

• monitored by optical spectroscopy [56][73]. The synthetic route can easily be applied to other material compositions as previously demonstrated by the formation of heterostructures composed out of gold and manganese oxide [39]. Au@MnO heterodimers were prepared using preformed Au nanoparticles as seeds, as

• the domain sizes of Au@MnO heterodimer nanoparticles in comparison to spherical Au nanoparticles. The shift of the absorption maximum amounts to 30 to 60 nm depending on the ratio of the domain sizes of Au and MnO. Mie’s theory describes the direct dependence of the surface plasmon resonance from the

Electrical contacts to individual SWCNTs: A review

• Wei Liu,
• Christofer Hierold and
• Miroslav Haluska

Beilstein J. Nanotechnol. 2014, 5, 2202–2215, doi:10.3762/bjnano.5.229

• most cases. This can be explained by the relatively poor wettability of gold to SWCNTs. As shown in Figure 7a, discrete Au nanoparticles are formed on suspended SWCNTs [57]. In contrast, Pd forms a nearly continuous coating on the SWCNT [57], which indicates a good adhesion to the sidewall of carbon