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

• ; polyelectrolyte; Introduction Surface-enhanced Raman scattering (SERS) spectroscopy, which relies on metal nanostructures made of noble metals (Au, Ag and Cu) that sustain localized surface plasmon resonance (LSPR), is applied as a promising analytical tool for detecting and identifying trace amounts of

• mainly driven by electrostatic interaction. Especially, multilayer thin films consisting of polymers and metal nanoparticles (NPs) have been extensively explored, and show interesting optical and SERS properties [9][10][11][12][13][14]. Wang and Dong et al. reported that polyelectrolyte–gold nanorod

• be assembled onto polyelectrolyte multilayer films and act as seeds for the following NP growth [16]. The grown NP films were demonstrated to be stable and reproducible SERS substrates. In addition to assembling only one type of NPs, Zhang et al. fabricated bimetallic gold–silver multilayer films by

3D solid supported inter-polyelectrolyte complexes obtained by the alternate deposition of poly(diallyldimethylammonium chloride) and poly(sodium 4-styrenesulfonate)

• Eduardo Guzmán,
• Armando Maestro,
• Sara Llamas,
• Jesús Álvarez-Rodríguez,
• Francisco Ortega,
• Ángel Maroto-Valiente and
• Ramón G. Rubio

Beilstein J. Nanotechnol. 2016, 7, 197–208, doi:10.3762/bjnano.7.18

• Ciencias Universidad Nacional de Educación a Distancia, C/ Senda del Rey 9, 28040 Madrid Instituto Pluridisciplinar, Universidad Complutense de Madrid Avda. Juan XXIII 1, 28040 Madrid, Spain 10.3762/bjnano.7.18 Abstract This work addresses the formation and the internal morphology of polyelectrolyte

• -dimensional solid-supported inter-polyelectrolyte films. The growth mechanism of the multilayers, followed using a quartz crystal microbalance, evidences two different growth trends, which show a dependency on the ionic strength due to its influence onto the polymer conformation. The hydration state does not

• modify the multilayer growth, but it contributes to the total adsorbed mass of the film. The water associated with the polyelectrolyte films leads to their swelling and plastification. The use of X-ray photoelectron spectroscopy has allowed for deeper insights on the internal structure and composition of

Fabrication and characterization of novel multilayered structures by stereocomplexion of poly(D-lactic acid)/poly(L-lactic acid) and self-assembly of polyelectrolytes

• Elena Dellacasa,
• Li Zhao,
• Gesheng Yang,
• Laura Pastorino and
• Gleb B. Sukhorukov

Beilstein J. Nanotechnol. 2016, 7, 81–90, doi:10.3762/bjnano.7.10

• , which only gave information about mass change [35]. Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) was used to verify the stereocomplex formation and its effective adsorption onto the polyelectrolyte precursor. Differential scanning calorimetry (DSC) and wide X-ray

• nm while the thickness of the PLL/(PDLA/PLLA)5 multilayers deposited onto bare silicon (Figure 4b) was found to be 23.5 nm, indicating again that the polyelectrolyte multilayer precursor has no particular effect on the thickness of the PLA multilayer. This is different from the results of other

• research on the behavior of the growth of conventional polyelectrolyte multilayers, where the underlying precursor was shown to have some influence [47]. Another phenomenon that was observed is that an odd number of PLA layers is always thicker than an even number of layers. This is due to the “dotted

Counterion effects on nano-confined metal–drug–DNA complexes

• Nupur Biswas,
• Sreeja Chakraborty,
• Alokmay Datta,
• Munna Sarkar,
• Mrinmay K. Mukhopadhyay,
• Mrinal K. Bera and
• Hideki Seto

Beilstein J. Nanotechnol. 2016, 7, 62–67, doi:10.3762/bjnano.7.7

• –DNA composites; polyelectrolyte; X-ray scattering; Introduction Condensed state behaviour of DNA, the best-known biopolymer, in a confined space is a matter of interest due to its relevance in living systems. Within cells DNA molecules remain in a confined space crowded by other molecules and ions

pH-Triggered release from surface-modified poly(lactic-co-glycolic acid) nanoparticles

• Manuel Häuser,
• Klaus Langer and
• Monika Schönhoff

Beilstein J. Nanotechnol. 2015, 6, 2504–2512, doi:10.3762/bjnano.6.260

• the nanoparticles with high concentrations of sodium chloride shows no further release and thus demonstrates the pH-driven release to be quantitative. Keywords: layer-by-layer self-assembly; pH-triggered release; PLGA nanoparticles; polyelectrolyte multilayers; weak polyelectrolyte; Introduction The

• ultrathin polyelectrolyte multilayers (PEM) with well adjustable properties and architecture. Layer build-up is based on alternating adsorption of cationic and anionic compounds, such as polyelectrolytes [15], proteins [16], nucleic acids [17][18], dyes [19], and even colloids [14] onto the surface of

• they are adsorbed. In case of PAA, a shift of acidity has been reported by several research groups, comparing free polyelectrolyte chains in solution to PAA in multilayers [20], and also the growth behaviour of the layer was shown to depend strongly on the pH value [21]. In the meantime

Fabrication of hybrid graphene oxide/polyelectrolyte capsules by means of layer-by-layer assembly on erythrocyte cell templates

• Joseba Irigoyen,
• Nikolaos Politakos,
• Eleftheria Diamanti,
• Elena Rojas,
• Marco Marradi,
• Raquel Ledezma,
• Layza Arizmendi,
• J. Alberto Rodríguez,
• Ronald F. Ziolo and
• Sergio E. Moya

Beilstein J. Nanotechnol. 2015, 6, 2310–2318, doi:10.3762/bjnano.6.237

• , Centro de Investigación en Química Aplicada, Blvd. Enrique Reyna Hermosillo No.140 C.P. 25294 Saltillo, Coahuila, México 10.3762/bjnano.6.237 Abstract A novel and facile method was developed to produce hybrid graphene oxide (GO)–polyelectrolyte (PE) capsules using erythrocyte cells as templates. The

• capsules are easily produced through the layer-by-layer technique using alternating polyelectrolyte layers and GO sheets. The amount of GO and therefore its coverage in the resulting capsules can be tuned by adjusting the concentration of the GO dispersion during the assembly. The capsules retain the

• FTIR spectroscopies. Keywords: capsules; erythrocytes; graphene; layer by layer; polyelectrolyte membranes; Introduction The past decades have witnessed explosive growth in research on low-dimensional carbon forms with graphene and carbon nanotubes in the forefront [1][2][3]. The unique electrical

Self-assembled anchor layers/polysaccharide coatings on titanium surfaces: a study of functionalization and stability

• Ognen Pop-Georgievski,
• Dana Kubies,
• Josef Zemek,
• Neda Neykova,
• Roman Demianchuk,
• Eliška Mázl Chánová,
• Miroslav Šlouf,
• Milan Houska and
• František Rypáček

Beilstein J. Nanotechnol. 2015, 6, 617–631, doi:10.3762/bjnano.6.63

• ]. Chitosan/alginate, multilayered, 3D networks prepared by the layer-by-layer method enabled encapsulation of bone marrow stromal cells on the surface of dental or joint implants [18]. Polyelectrolyte (chitosan, poly(L-glutamic acid), and poly-L-lysine) coatings increased the surface ionic nature and

Exploring plasmonic coupling in hole-cap arrays

• Thomas M. Schmidt,
• Maj Frederiksen,
• Vladimir Bochenkov and
• Duncan S. Sutherland

Beilstein J. Nanotechnol. 2015, 6, 1–10, doi:10.3762/bjnano.6.1

• mercury grid lamp from BHK Inc. Colloidal assembly of the nanoparticles to generate dispersed colloidal monolayers masks was carried out by an approach described elsewhere [24]. In brief the surfaces were modified with a polyelectrolyte triple layer by sequential deposition from a 2% w/v PDDA, a 2% w/v

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

• dots starting with a CdSe core. Adapted with permission from [13]. Copyright 2005 American Chemical Society. Summary of synthetic routes towards organic Janus particles. (a) Directed functionalization after immobilization, (b) ellipsoidal complex core coacervate micelle with an inter-polyelectrolyte

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

• polyelectrolyte that is protonated in acidic solutions, whereas at pH > 8, it exists in the free alkaline form [23]. PEI is often used as a colloidal metal nanoparticle and metal oxide stabiliser. Studies show that many metal nanoparticles (such as silver, gold, zinc oxide or tin dioxide) synthesised in solutions

• processes can be effectively controlled with the acidity of the solution, because PEI (which has undergone deprotonation) does not stabilise the nanoparticles. In the presence of PVP (the second of the stabilisers used, Table 2 and Table 5), the process happens differently. PVP is a linear, polyelectrolyte

Biopolymer colloids for controlling and templating inorganic synthesis

• Laura C. Preiss,
• Katharina Landfester and
• Rafael Muñoz-Espí

Beilstein J. Nanotechnol. 2014, 5, 2129–2138, doi:10.3762/bjnano.5.222

• which biocompatibility or biodegradability are an issue, such as biomedical applications. In addition, biopolymers may be also good model systems. In this sense, for instance, peptides or nucleic acids of defined length and structure can be very convenient models for studying polyelectrolyte systems

Influence of surface-modified maghemite nanoparticles on in vitro survival of human stem cells

• Michal Babič,
• Daniel Horák,
• Lyubov L. Lukash,
• Tetiana A. Ruban,
• Yurii N. Kolomiets,
• Svitlana P. Shpylova and
• Oksana A. Grypych

Beilstein J. Nanotechnol. 2014, 5, 1732–1737, doi:10.3762/bjnano.5.183

• ., dextran [18][19] (in Feridex® and Endorem® developed as contrast agents for magnetic resonance imaging, MRI), poly(ethylene glycol) (PEG) [1], poly(N,N-dimethylacrylamide) (PDMAAm) [20], poly(L-lysine) [21][22], protamine sulfate [23], or layer-by-layer polyelectrolyte complexes [24]. The aim of this

In vitro and in vivo interactions of selected nanoparticles with rodent serum proteins and their consequences in biokinetics

• Wolfgang G. Kreyling,
• Stefanie Fertsch-Gapp,
• Martin Schäffler,
• Blair D. Johnston,
• Nadine Haberl,
• Christian Pfeiffer,
• Jörg Diendorf,
• Carsten Schleh,
• Stephanie Hirn,
• Manuela Semmler-Behnke,
• Matthias Epple and
• Wolfgang J. Parak

Beilstein J. Nanotechnol. 2014, 5, 1699–1711, doi:10.3762/bjnano.5.180

• –protein conjugates we engineered such conjugates by using either albumin or apolipoprotein E grafted through polyelectrolyte links onto the surface of 15 nm or 80 nm AuNP prior to intravenous injection into mice [15]. Indeed, we observed remarkable differences in the biokinetics pattern during the first

In vitro toxicity and bioimaging studies of gold nanorods formulations coated with biofunctional thiol-PEG molecules and Pluronic block copolymers

• Tianxun Gong,
• Douglas Goh,
• Malini Olivo and
• Ken-Tye Yong

Beilstein J. Nanotechnol. 2014, 5, 546–553, doi:10.3762/bjnano.5.64

• nanoparticle formulations. For example, Alkilany et al. demonstrated the use of polyacrylic acid (PAA) and polyelectrolyte poly(allylamine) hydrochloride (PAH) to coat AuNRs surface. The coating was performed on as-synthesized CTAB-coated AuNRs after a washing treatment by centrifugation [15]. The CTAB-coated

Controlled synthesis and tunable properties of ultrathin silica nanotubes through spontaneous polycondensation on polyamine fibrils

• Jian-Jun Yuan,
• Pei-Xin Zhu,
• Daisuke Noda and
• Ren-Hua Jin

Beilstein J. Nanotechnol. 2013, 4, 793–804, doi:10.3762/bjnano.4.90

• controlled by polyelectrolyte adsorption. Conclusion We have demonstrated that well-defined silica nanotubes of 10 nm diameter could be easily synthesized in solution through a templated silica mineralization on self-assembled LPEI fibrils, which in turn were formed by alkali-induced rapid deprotonation

• under N2 atmosphere. Moreover, silica/carbon composite nanotubes with tunable compositions could be synthesized by adsorption of a polyelectrolyte on LPEI@silica hybrid nanotubes and the subsequent carbonization. Experimental Materials. LPEI·HCl with about 500 EI repeating units was synthesized by the

Growth behaviour and mechanical properties of PLL/HA multilayer films studied by AFM

• Cagri Üzüm,
• Johannes Hellwig,
• Narayanan Madaboosi,
• Dmitry Volodkin and
• Regine von Klitzing

Beilstein J. Nanotechnol. 2012, 3, 778–788, doi:10.3762/bjnano.3.87

• measurements show that PLL/HA films have a viscoelastic behaviour, regardless of their thickness. If indentation is performed several times at the same lateral position on the film, a viscous/plastic deformation takes place. Keywords: atomic force microscopy; polyelectrolyte multilayers; stress relaxation

• ; viscoelasticity; Young’s modulus; Introduction Polyelectrolyte multilayers (PEMs) have been studied intensely for the past two decades [1][2]. Despite their complex structure and wide range of applicability, PEMs can be prepared simply by alternating deposition of polycations and polyanions by dipping/spraying a

• substrate into/with the corresponding polyelectrolyte solutions. Potential applications of PEMs (e.g., filtration, paper making and biomaterials) require control of their adhesive behaviour by tuning the elastic/viscoelastic properties [3][4][5]. For example, the adsorption behaviour of proteins and cells

Horizontal versus vertical charge and energy transfer in hybrid assemblies of semiconductor nanoparticles

• Gilad Gotesman,
• Rahamim Guliamov and
• Ron Naaman

Beilstein J. Nanotechnol. 2012, 3, 629–636, doi:10.3762/bjnano.3.72

• ) and PL-lifetime measurements of donor–acceptor NP bilayers, separated by polyelectrolyte layers, revealed that the energy transfer rate is inversely related to the distance. This is consistent with Förster’s theory for the dipole–dipole energy transfer mechanism in the donor–acceptor bilayers [25][26

Macromolecular shape and interactions in layer-by-layer assemblies within cylindrical nanopores

• Thomas D. Lazzara,
• K. H. Aaron Lau,
• Wolfgang Knoll,
• Andreas Janshoff and
• Claudia Steinem

Beilstein J. Nanotechnol. 2012, 3, 475–484, doi:10.3762/bjnano.3.54

• , hexagonally close-packed, cylindrical pores running straight through the AAO membrane thickness, with conveniently adjustable monodisperse pore diameters, degree of lattice spacing, and membrane thickness [27][28][29], making it well suited as a model nanoporous system [30][31][32]. LbL of polyelectrolyte

• charged species, in which polyelectrolyte strength, polyelectrolyte chemical structure and solution ionic strength can strongly influence deposition within the nanopores [32]. On the other hand, the confined cylindrical nanopore environment imposes a steric constraint, in which pore walls are physical

• -workers have recently simulated the pore-filling behavior during LbL deposition of both nanoparticle–polyelectrolyte [34] and polyelectrolyte–polyelectrolyte structures [35]. For the fabrication of LbL structures, both steric and electrostatic considerations related to the confined nanoporous geometry

Self-assembled monolayers and titanium dioxide: From surface patterning to potential applications

• Yaron Paz

Beilstein J. Nanotechnol. 2011, 2, 845–861, doi:10.3762/bjnano.2.94

• acid [35][36]. By choosing sulfonate-terminated SAMs with long alkyl chains (or a sulfonate-capped polyelectrolyte multilayer) and by careful manipulation of the solution parameters, an anatase phase can be obtained with this method, without the need for high-temperature treatment. The same LPD