Facile phase transfer of gold nanorods and nanospheres stabilized with block copolymers

• Yaroslav I. Derikov,
• Georgiy A. Shandryuk,
• Raisa V. Talroze,
• Alexander A. Ezhov and
• Yaroslav V. Kudryavtsev

Beilstein J. Nanotechnol. 2018, 9, 616–627, doi:10.3762/bjnano.9.58

• nanorods depend on the refractive index of a medium bordering the nanorod surface. The effect is more pronounced for the TM mode. As shown in [47], in hydrosols, CTAB forms a 4–5 nm bilayer at the surface of Au nanoparticles. The optical dispersion curves for the substances relevant to this study are

• presented in Figure 3. For the sodium D-line, the refractive index of CTAB equals 1.4350 [48], which is close to 1.4440 for chloroform [49], but markedly different from 1.3333 for water [43], 1.4956 for benzene [44], 1.4920 for toluene [44], 1.5915 for polystyrene [50] and 1.622 for poly(2-vinylpyridine) at

• 436 nm [51]. Thus, the presence of a CTAB bilayer at the Au nanorod surface should noticeably shift the maximum position of the TM plasmon resonance in water and benzene. This can be checked by simulations for a model in which a single nanorod is coated with a surface layer with the refractive index

The role of ligands in coinage-metal nanoparticles for electronics

• Ioannis Kanelidis and
• Tobias Kraus

Beilstein J. Nanotechnol. 2017, 8, 2625–2639, doi:10.3762/bjnano.8.263

• initial nucleation processes of particle synthesis; this is probably the mechanism of the formation of ultrathin gold nanowires [64]. Silver nanoparticle synthesis by reduction of silver salts is an important case of ligand-directed nanoparticle growth. Cetyltrimethylammonium bromide (CTAB, Figure 2) in

• combination with ascorbic acid and spherical silver seeds yielded rod-like structures in water by reduction of AgNO3. Jana, Gearheart, and Murphy suggested that CTAB forms micellar templates for the anisotropic growth of nanostructures [65]. Recent studies modified this picture and indicated that CTAB

• formation of gold nanorods with controllable aspect ratios. In the presence of CTAB alone, rods with a broad size distribution formed (see above [65]) in a mixture with other shapes. An improved protocol with a binary surfactant mixture of CTAB and sodium oleate led to gold nanorods with a narrower size

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

• the latter approach, control over the shape and size of the synthesized particles is limited. The metal nanoparticles were stabilized before the coating step using various surfactants or stabilizing agents such as Lutensol ON50 [21], cetyltrimethylammonium bromide (CTAB) [27][28][29][30][40], anionic

Fabrication of hierarchically porous TiO₂ nanofibers by microemulsion electrospinning and their application as anode material for lithium-ion batteries

• Jin Zhang,
• Yibing Cai,
• Xuebin Hou,
• Xiaofei Song,
• Pengfei Lv,
• Huimin Zhou and
• Qufu Wei

Beilstein J. Nanotechnol. 2017, 8, 1297–1306, doi:10.3762/bjnano.8.131

• acid and cetyltrimethylammonium bromide (CTAB) were supplied by Shanghai Chemical Regents Co. (Shanghai, China). Additionally, polyvinyl pyrrolidone (PVP) (Mw = 1300000) was purchased from Tianjin Bodi Chemical Reagent Co., Ltd. (Tianjin, China). All chemicals were used as received without further

• purification. Preparation of the spinning solution 0.5 g PVP and 0.3 g CTAB were firstly dissolved into 6.5 g ethanol and 0.4 g acetic acid followed by vigorously stirring to form a homogeneous solution. Subsequently, 1 g paraffin oil and stoichiometric amounts of TBT with different TBT/paraffin oil ratios (w

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

• AuNPs. The TEM images of AuNSs and AuNRs are shown in Figure 3, which reveal the formation of Au–DNA NCs [29]. These AuNSs were found to be separated from each other due to the CTAB coating on their surface, which renders them to have a positive charge [30]. The dynamic light scattering (DLS) results

• propionic acid (MPA). The synthesized AuNSs had a CTAB coating and were positively charged in nature. The values obtained for the zeta potential, conductance and mobility are summarized in Supporting Information File 1, Table S2. In Figure 7, the zeta potential is given before binding with DNA for bare

• bromide (CTAB) and DL-dithiothreitol solution (DTT) were purchased from Sigma Aldrich. Sodium borohydride (NaBH4) and silver nitrate (AgNO3) were purchased from Rankem and Fisher Scientific, respectively. Chloroauric acid (HAuCl4·H2O), ascorbic acid, mercaptopropionic acid (MPA) and magnesium acetate (Mg

Dispersion of single-wall carbon nanotubes with supramolecular Congo red – properties of the complexes and mechanism of the interaction

• Anna Jagusiak,
• Barbara Piekarska,
• Tomasz Pańczyk,
• Małgorzata Jemioła-Rzemińska,
• Elżbieta Bielańska,
• Barbara Stopa,
• Grzegorz Zemanek,
• Janina Rybarska,
• Irena Roterman and
• Leszek Konieczny

Beilstein J. Nanotechnol. 2017, 8, 636–648, doi:10.3762/bjnano.8.68

• length influences CNT toxicity and cellular uptake [22][23]. Surfactants commonly used for dispersion of CNTs include SDS, CTAB, Triton X-100 or sodium cholate [24][25][26]. A less known approach is based on the interaction of CNTs with a bis-azo dye – Congo red (CR) [27]. This original procedure was

Comparison of four methods for the biofunctionalization of gold nanorods by the introduction of sulfhydryl groups to antibodies

• Xuefeng Wang,
• Zhong Mei,
• Yanyan Wang and
• Liang Tang

Beilstein J. Nanotechnol. 2017, 8, 372–380, doi:10.3762/bjnano.8.39

• solution and the CTAB bilayer density [15]. The common ligand exchange is the replacement of the CTAB of GNR with thiol-terminated ligands, such as thiolated poly(ethylene glycol) and mercaptoundecanoic acid [10][11]. These agents can link the amino groups of biomolecules with the carboxylic group from

• the GNR surfaces after binding of anti-IgG. The four modified anti-IgG all induced a decrease in zeta potential after conjugation. This is consistent with previously reported observations that GNR surface potentials decrease after bioconjugation from highly positive surface charges packed with CTAB, a

• cationic surfactant bilayer [17][24], because of the replacement of CTAB by thiolated anti-IgG [17][25]. Anti-IgG were detected in thiolation and nanoconjugates with GNRs, but not in free GNRs, by gel electrophoresis followed by Coomassie brilliant blue staining (Figure S1, Supporting Information File 1

Nanoscale isoindigo-carriers: self-assembly and tunable properties

• Tatiana N. Pashirova,
• Andrei V. Bogdanov,
• Lenar I. Musin,
• Julia K. Voronina,
• Irek R. Nizameev,
• Marsil K. Kadirov,
• Vladimir F. Mironov,
• Lucia Ya. Zakharova,
• Shamil K. Latypov and
• Oleg G. Sinyashin

Beilstein J. Nanotechnol. 2017, 8, 313–324, doi:10.3762/bjnano.8.34

• , respectively, two times and 20 times higher than that of the classical surfactants, CTAB and SDS. Fluorescence studies showed that significant changes occur in the pyrene spectrum of the isoindigo derivatives in solution for all the compounds under study, regardless the length of the alkyl chain (Figure 4b

• available classical anionic (SDS), cationic (CTAB) and nonionic (Tween 80) surfactants. Because isatin and isoindigo derivatives are new dyes, their extinction coefficients were determined for the first time. UV–vis absorption spectra of 2a–h and 3 in chloroform are presented in Figures S11–S18 (Supporting

• of that of isoindigo 2a. The solubilization of compound 3 is observed in micellar solutions of CTAB and Tween 80 (Figure S23 and Figure S24, Supporting Information File 1). It is noteworthy that apart from the solubilization mechanism by typical interaction between surfactants and dyes, mixed

Organoclay hybrid materials as precursors of porous ZnO/silica-clay heterostructures for photocatalytic applications

• Marwa Akkari,
• Pilar Aranda,
• Abdessalem Ben Haj Amara and
• Eduardo Ruiz-Hitzky

Beilstein J. Nanotechnol. 2016, 7, 1971–1982, doi:10.3762/bjnano.7.188

• the Experimental section, the intermediate/silica-organoclay samples were firstly prepared and, in a second step, were treated with freshly synthesized ZnO NP dispersed in 2-propanol (Figure 1A). The XRD diagrams (Figure 2) of the two layered silicates treated with CTAB, Cloisite® (CLO-CTA) and

• and the organoclay obtained by treatment with CTAB revealed not changes, confirming that the surfactant is just assembled to the external surface of the clay (Figure 6). This technique also reveals that the hydrolysis and polycondensation of TMOS to produce silica NP on the organo-sepiolite surface

• incorporation of SiO2 NP giving rise to delaminated heterostructures, whereas sepiolite is modified exclusively on its external surface. The SiO2 NP are generated by controlled hydrolysis and polycondensation of TMOS on the organophilic surface of both types of silicates previously treated with CTAB surfactant

Straightforward and robust synthesis of monodisperse surface-functionalized gold nanoclusters

• Silvia Varela-Aramburu,
• Richard Wirth,
• Chian-Hui Lai,
• Guillermo Orts-Gil and
• Peter H. Seeberger

Beilstein J. Nanotechnol. 2016, 7, 1278–1283, doi:10.3762/bjnano.7.118

• bromide (CTAB-NCs) and tetrakis(hydroxymethyl)phosphonium chloride (THPC-NCs) as determined by UV absorbance. Gold nanoparticles smaller than 5 nm do not display a plasmon band. The Glc-NCs are stable and showed the same absorbance profile after three days of dialysis (Figure 1B). In contrast, the CTAB

• -NCs and the THPC-NCs exhibit plasmon bands (Figure S6, Supporting Information File 1). The CTAB-NCs showed a plasmon band directly after synthesis, which shifted to longer wavelengths after three days, suggesting an increasing rate of aggregation. TEM images of freshly prepared CTAB-NCs revealed

• for one day with the mouse cell line L929 for a proof-of-principle study. Cell viability was measured using the MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium inner salt] assay [30]. The cytotoxicity of Glc-NCs, CTAB-NCs and THPC-NCs was compared. CTAB

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

• [35]. In the second step a mesoporous shell was grown on the spheres by employing tetraethyl orthosilicate in presence of cetyltrimethylammonium bromide (CTAB) as a structure-directing agent. Combustion of CTAB in air generated the core–shell silica spheres. The diameter of the solid core was

Tunable longitudinal modes in extended silver nanoparticle assemblies

• Serene S. Bayram,
• Klas Lindfors and
• Amy Szuchmacher Blum

Beilstein J. Nanotechnol. 2016, 7, 1219–1228, doi:10.3762/bjnano.7.113

• by CTAB (cetyltrimethylammonium bromide) also did not reveal well-resolved anisotropy [25]. Our simulation results suggest that the inability of either of these AgNPs assemblies to support anisotropic optical modes could have been due to reduced polarizability, the short length of the nanoparticle

• solvent intervention in the mode of self-assembly of nanostructures was presented by Fava and co-workers. Side-to-side (via the CTAB-capped (100) facet) assembly of gold nanorods was favoured at a high content of the solvent tetrahydrofuran (THF), where THF is known to poorly solubilize CTAB. In contrast

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

• size and preferred growth planes of {111}. On the other hand, it is proposed [40] that cetyltrimethylammonium bromide (CTAB), used as a surfactant in this work, has a preferential binding to specific side faces of gold particles, slowing down the nucleation on these side planes and allowing growth of

• of 0.2 M cetyltrimethylammonium bromide (CTAB), 250 μL of 0.01 M AuCl4−, 50 μL of 0.1 M ascorbic acid and 20 μL of 0.1 M HNO3 and kept undisturbed overnight at room temperature (ca. 24 °C). This step leads to the growth of protruded gold seeds into GNRs via seed-mediated growth. Atomic force

Surface coating affects behavior of metallic nanoparticles in a biological environment

• Darija Domazet Jurašin,
• Marija Ćurlin,
• Ivona Capjak,
• Tea Crnković,
• Marija Lovrić,
• Michal Babič,
• Daniel Horák,
• Ivana Vinković Vrček and
• Srećko Gajović

Beilstein J. Nanotechnol. 2016, 7, 246–262, doi:10.3762/bjnano.7.23

• ), agglomerated NPs are characterized by very high polydispersity. The CTAB and Tween coatings prevented severe agglomeration of AgNPs in BM due to steric repulsion effects. According to the volume-weighted size distribution data, less than 10% of TweenAgNPs population agglomerated in BM, while 50% of CTAAgNPs

• coated with AOT, Brij, Tween, PLL and CTAB, and SPIONs were strongly damaged and had irregular surfaces (Figure 6). In summary, different coating agents used on AgNPs and SPIONs imparted different colloidal stabilities in the same biological media. The obtained data clearly show that a combination of

• stirring on an IKA RCT basic magnetic stirrer plate (IKA Werke, Germany). To this solution, a volume of 2 mL of 0.4 M NaBH4 solution was added dropwise (about 1 drop/s). The final concentrations of AOT, CTAB, PVP, PLL, and Tween were 500, 500, 75, 20 and 6 mM, respectively. The reaction mixture was stirred

Characterisation of thin films of graphene–surfactant composites produced through a novel semi-automated method

• Nik J. Walch,
• Alexei Nabok,
• Frank Davis and
• Séamus P. J. Higson

Beilstein J. Nanotechnol. 2016, 7, 209–219, doi:10.3762/bjnano.7.19

• bromide (CTAB). The formation of individual graphene flakes was confirmed by Raman spectroscopy, while the interaction of graphene with surfactants was proven by NMR spectroscopy. The resulting graphene–surfactant composite material formed a stable suspension in water and some organic solvents, such as

• Semi-automated sonochemical exfoliation of graphene Two different surfactants were used to synthesise graphene–surfactant complexes: sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB). Firstly the surfactant solutions were prepared by dissolving in water. The SDS solution was made

• to a concentration of 462.9 mg·mL−1 while the CTAB solution concentration was made up to 49.7 mg·mL−1. These solutions were prepared and then placed into a water bath heated to 50 °C to aid dissolution. Once dissolved, the surfactant solution was placed into the surfactant reservoir of the

Morphology control of zinc oxide films via polysaccharide-mediated, low temperature, chemical bath deposition

• Florian Waltz,
• Hans-Christoph Schwarz,
• Andreas M. Schneider,
• Stefanie Eiden and
• Peter Behrens

Beilstein J. Nanotechnol. 2015, 6, 799–808, doi:10.3762/bjnano.6.83

• (malate) [36], ascorbate [37], diaminopropane [38], hexadecyl(trimethyl)azanium bromide (CTAB) [39], and block copolymers [40] have been used for this purpose, in addition to naturally occurring amino acids and peptides [41], which have already been successfully applied in this respect. We recently

Silica micro/nanospheres for theranostics: from bimodal MRI and fluorescent imaging probes to cancer therapy

• Shanka Walia and
• Amitabha Acharya

Beilstein J. Nanotechnol. 2015, 6, 546–558, doi:10.3762/bjnano.6.57

• trimethylammonium bromide (CTAB), butanol and hexane as surfactant, co-surfactant and oil phase, respectively. The silica coating of the Gd2(CO3)3:Tb complex was done by using tetraethylorthosilicate (TEOS) under ammonical conditions. The synthesized NPs were characterized by HRTEM, EDX and FTIR. The size of the

• synthesis was enhanced by using Y(NO3)3·6H2O and Eu2O3 as reactants, CTAB as surfactant and TEOS as alkyl silicate. Finally, the anticancer drug doxyrubicin (DOX) was loaded into the prepared NPs. Characterization of mesoporous silica NPs (MSN), YVO4:Eu3+ NPs and YVO4-MSNs were done by XRD, FTIR, TEM and

• inside the silica spheres by using CTAB as template surfactant. Finally complexes of lanthanides, namely Eu3+, Tb3+ with nicotinic and isonicotinic acid were introduce inside silica. The characterization of these multifunctional nanostructures was achieved by UV–vis absorption spectroscopy, XRD

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

• [7] are suggested. Gold nanorods were shown to have better optical imaging properties compared to spherical gold nanoparticles [8][9][10]. Importantly, the cytotoxicity of gold nanoparticles depends on the surface coating. Cetyltrimethylammonium bromide (CTAB), an important material during synthesis

• microscopy (TEM) investigations were performed. Spherical CTAB-modified gold nanoparticles with a size of 40 nm were localized in vacuoles after 1 h of incubation (Figure 5a). After a 1 h treatment of cells only, Au-NH2@Fe3O4 (20 nm) and spherical Au (4 nm) nanoparticles were shown to be internalized into

• nanoparticle type due to the inhibition of ATP utilizing enzymes [59]. A strong cytotoxicity of genistein per se on endothelial cells could be excluded by the intact cell morphology shown in Figure S2 (Supporting Information File 1). The incubation of cells with CTAB-modified gold rods and spheres showed a

Mechanical properties of MDCK II cells exposed to gold nanorods

• Anna Pietuch,
• Bastian Rouven Brückner,
• David Schneider,
• Marco Tarantola,
• Christina Rosman,
• Carsten Sönnichsen and
• Andreas Janshoff

Beilstein J. Nanotechnol. 2015, 6, 223–231, doi:10.3762/bjnano.6.21

• fluorescence and dark-field microscopy. Conclusion: We found that cells exposed to CTAB coated gold nanorods display a concentration-dependent stiffening that cannot be explained by the presence of CTAB alone. The stiffening results presumably from endocytosis of particles removing excess membrane area from

• CTAB coated rods suggesting an increase in acoustic load corresponding to a larger stiffness (storage modulus). Keywords: atomic force microscopy; CTAB; gold nanorods; membrane tension; MDCK II cells; QCM; Introduction The interest in gold nanoparticles (NP) for biomedical applications in the field

• either cetyl-trimethylammonium bromide (CTAB) or biocompatible polyethylene glycol (PEG) coated gold nanoparticles in different concentrations. We also examined structural rearrangement of the cytoskeleton via fluorescence microscopy and by that tried to gain a deeper understanding of how gold

Mammalian cell growth on gold nanoparticle-decorated substrates is influenced by the nanoparticle coating

• Christina Rosman,
• Sebastien Pierrat,
• Marco Tarantola,
• David Schneider,
• Eva Sunnick,
• Andreas Janshoff and
• Carsten Sönnichsen

Beilstein J. Nanotechnol. 2014, 5, 2479–2488, doi:10.3762/bjnano.5.257

• results to cell growth on bare substrates. The study utilized three different surface coatings because the particle-bound molecules (stabilizing agents) are expected to promote diverse interactions with the cell membrane [21][22]. One coating consists of cetyltrimethylammonium bromide (CTAB), which is a

• relatively cytotoxic cationic surfactant [11] present on the particle surface after synthesis. These CTAB molecules can be replaced by the inert polymer poly(ethylene glycol) (PEG), which is known to be biocompatible [23]. To investigate the influence of reactive groups, we use PEG chains exhibiting either

• amine (NH2–PEG) or carboxy groups (COOH–PEG). The different surface coatings result in positively charged (CTAB, ζ-potential approx. +50 mV) [24], neutral (NH2–PEG, ζ-potential approx. 0 mV), and negatively charged (COOH–PEG, ζ-potential approx. −20 mV) nanoparticles, respectively. The ζ-potentials

Influence of stabilising agents and pH on the size of SnO₂ nanoparticles

• Olga Rac,
• Patrycja Suchorska-Woźniak,
• Marta Fiedot and
• Helena Teterycz

Beilstein J. Nanotechnol. 2014, 5, 2192–2201, doi:10.3762/bjnano.5.228

• were obtained by combining a spray pyrolysis method and annealing carried out under atmospheric pressure. The subject of the synthesis of SnO2 nanoparticles in aqueous solution rarely occurs in the literature. SnO2 colloidal synthesis in cetyltrimethylammonium bromide (CTAB) micelles (where tin

Non-covalent and reversible functionalization of carbon nanotubes

• Antonello Di Crescenzo,
• Valeria Ettorre and
• Antonella Fontana

Beilstein J. Nanotechnol. 2014, 5, 1675–1690, doi:10.3762/bjnano.5.178

• suspensions. During the years stable aqueous CNTs dispersions were obtained with differently charged and non-ionic commercial surfactants such as sodium dodecylbenzen sulfonate (SDBS), cetyltrimethylammonium p-toluenesulfonate (CTAT), cetyltrimethylammonium bromide (CTAB) and sodium cholate (SC) enhanced by

Current state of laser synthesis of metal and alloy nanoparticles as ligand-free reference materials for nano-toxicological assays

• Christoph Rehbock,
• Jurij Jakobi,
• Lisa Gamrad,
• Selina van der Meer,
• Daniela Tiedemann,
• Ulrike Taylor,
• Wilfried Kues,
• Detlef Rath and
• Stephan Barcikowski

Beilstein J. Nanotechnol. 2014, 5, 1523–1541, doi:10.3762/bjnano.5.165

• the presence of artificial stabilizers. These stabilizers are known to interfere with toxicological assays [15], as reported, e.g., for cytotoxic CTAB [16][17] as well as for citrate [18][19], which is generally believed to be biocompatible. Next to toxicity, ligands like citrate may also influence

• pulse lengths but has not yet been sufficiently explained [43]. However, even though oxidation is meant to generate a positive surface charge, zeta potentials of laser-generated gold nanoparticles are all negative and titration with the positively charged ligand CTAB was used to confirm the presence of

In vitro interaction of colloidal nanoparticles with mammalian cells: What have we learned thus far?

• Moritz Nazarenus,
• Qian Zhang,
• Mahmoud G. Soliman,
• Pablo del Pino,
• Beatriz Pelaz,
• Susana Carregal-Romero,
• Joanna Rejman,
• Barbara Rothen-Rutishauser,
• Martin J. D. Clift,
• Reinhard Zellner,
• G. Ulrich Nienhaus,
• James B. Delehanty,
• Igor L. Medintz and
• Wolfgang J. Parak

Beilstein J. Nanotechnol. 2014, 5, 1477–1490, doi:10.3762/bjnano.5.161

• effects can result from the NPs themselves (e.g., by their catalytic surface or by their organic coating, such as in the case of cetyltrimethylammonium bromide (CTAB), a surfactant commonly used to synthesize gold nanorods) or by ions released from the NPs [154][155]. Ion release from certain materials

Synthesis, characterization, and growth simulations of Cu–Pt bimetallic nanoclusters

• Subarna Khanal,
• Ana Spitale,
• Nabraj Bhattarai,
• Daniel Bahena,
• J. Jesus Velazquez-Salazar,
• Sergio Mejía-Rosales,
• Marcelo M. Mariscal and
• Miguel José-Yacaman

Beilstein J. Nanotechnol. 2014, 5, 1371–1379, doi:10.3762/bjnano.5.150

• . Experimental Chemicals and materials Reagent-grade chemicals from Sigma-Aldrich such as chloroplatinic acid hydrate (H2PtCl6·xH2O, 99.9%), copper(I) acetate (CuCO2CH3, 97%), tetraoctylammonium bromide (TOAB, 99%), hexadecyltrimethylammonium bromide (CTAB), sodium borohydrate (NaBH4), 1-dodecanethiol, toluene

• of 10 mL solution of tetraoctylammonium bromide (TOAB, 99%) by vigorously stirring for 15 min. The organic phase was separated and formed 15 mM concentration stock solution. In a second step, 0.03 g of copper(I) acetate and 0.240 g of hexadecyltrimethylammonium bromide (CTAB) were added into the 10