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

• Alessandro Buccolieri Antonio Serra Gabriele Giancane Daniela Manno GFA-Gruppo di Fisica Applicata, Dipartimento di Matematica e Fisica “E. De Giorgi”, Università del Salento Lecce, Italy 10.3762/bjnano.9.48 Abstract Silver nanoparticles were synthesized in the presence of saccharides and ammonia

• been identified: very low ammonia concentrations from 0.01 to 0.2 ppm, high ammonia concentrations from 20 to 350 ppm and, most importantly, the intermediate or physiological range of ammonia from 0.5 to 10 ppm. Keywords: electron diffraction; electron microscopy; NH3 sensors; silver nanoparticles; UV

• particular silver nanoparticles (AgNPs), are often considered for analytical application because of their peculiar optical and electrical properties [13]. The surface plasmon resonance (SPR) properties of metal nanoparticles are considered very useful for the use of colloidal solutions in the field of

Gas-assisted silver deposition with a focused electron beam

• Luisa Berger,
• Katarzyna Madajska,
• Iwona B. Szymanska,
• Katja Höflich,
• Mikhail N. Polyakov,
• Jakub Jurczyk,
• Carlos Guerra-Nuñez and
• Ivo Utke

Beilstein J. Nanotechnol. 2018, 9, 224–232, doi:10.3762/bjnano.9.24

• Figure 6b recorded on the background particles indicate that they are silver nanoparticles. The pattern corresponds to the Ag fcc pattern (green rings). Additionally, the EDX line scan spectrum in Figure 6c over two particles (indicated by red line in inset) confirms this assumption by clearly showing a

• high silver content in those particles. The particle sizes are significantly smaller than those in the FEBID structures and can range from 4 to 10 nm, as shown in the histogram in Figure 6d. We attribute this background deposition of silver nanoparticles either to competing thermal decomposition of the

Facile synthesis of silver/silver thiocyanate (Ag@AgSCN) plasmonic nanostructures with enhanced photocatalytic performance

• Xinfu Zhao,
• Dairong Chen,
• Abdul Qayum,
• Bo Chen and
• Xiuling Jiao

Beilstein J. Nanotechnol. 2017, 8, 2781–2789, doi:10.3762/bjnano.8.277

• nm. The absorption peak of silver nanoparticles becomes gradually stronger as the content of Ag increases, indicating that the sunlight utilization efficiency increases steadily. During UV irradiation, many defects are formed in AgSCN, including different interstitial sites and vacancies [29]. The

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

• of particle layers. For example, inks based on PVP-coated silver nanoparticles of different geometries were used to prepare conductive layers. Inks that contained only spheres (64 nm in diameter) formed layers with a conductivity of 769.2 S/cm at 70% metal mass fraction. Mixtures of spheres and

• -printed from inks based on silver–copper nanoparticles in 2-butoxyethanol acetate or electrocircuits from silver nanoparticles in water were inkjet-printed on paper substrates [50][91]. Alkanethiol-functionalized gold and silver nanoparticles in water exhibited increased dispersion stability with

• between the cores in deposited layers [96][97]. Silver nanoparticles stabilized by oleylamine ligands were immersed in 99.9% acetic acid in order to partially remove oleylamine, substitute it with acetic acid (Figure 2), and reduce the overall density of the ligand shell on the metal surface. The decrease

Fabrication of gold-coated PDMS surfaces with arrayed triangular micro/nanopyramids for use as SERS substrates

• Jingran Zhang,
• Yongda Yan,
• Peng Miao and
• Jianxiong Cai

Beilstein J. Nanotechnol. 2017, 8, 2271–2282, doi:10.3762/bjnano.8.227

• nanoparticles on a poly(methyl methacrylate) (PMMA) template, and malachite green on fish skin [27] was successfully detected. A flexible and transparent substrate consisting of silver nanoparticles on polyethylene terephthalate (PET) sheets was fabricated for in situ detection of R6G and thiram residues with a

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

• silver nanoparticles, respectively. The stirring was kept up for 12 h. After this time, the synthesized CSNs were centrifuged and washed several times with ethanol. Tunable resistive pulse sensing (TRPS) measurements Analogous to the description in [64], TRPS size distribution measurements were carried

Luminescent supramolecular hydrogels from a tripeptide and nitrogen-doped carbon nanodots

• Maria C. Cringoli,
• Slavko Kralj,
• Marina Kurbasic,
• Massimo Urban and
• Silvia Marchesan

Beilstein J. Nanotechnol. 2017, 8, 1553–1562, doi:10.3762/bjnano.8.157

• allows several molecular precursors to be employed, such as amino acids in aqueous solution [3]. As an example, L-tyrosine was used to form hydrophobic CNDs able to sense ions and silver nanoparticles [4]. Arginine or cysteine have also been efficiently employed as starting materials through a

Surface-enhanced Raman spectroscopy of cell lysates mixed with silver nanoparticles for tumor classification

• Mohamed Hassoun,
• Iwan W.Schie,
• Tatiana Tolstik,
• Sarmiza E. Stanca,
• Christoph Krafft and
• Juergen Popp

Beilstein J. Nanotechnol. 2017, 8, 1183–1190, doi:10.3762/bjnano.8.120

• immuno-functionalized nanoparticles turned out to be challenging for cell identification because they require complex preparation procedures. Here, a new SERS strategy is presented for cell classification using non-functionalized silver nanoparticles and potassium chloride to induce aggregation. To

• silver nanoparticles. Keywords: cell lysate; silver nanoparticles; surface-enhanced Raman spectroscopy (SERS); tumor-cell differentiation; Introduction Cytopathology is the histopathologic inspection of cells. Dyes, such as hematoxylin for cell nuclei or eosin for cytoplasm, are commonly used to stain

• developed to disrupt the cell walls by sonication and to allow for the interaction of silver nanoparticles with the released cellular biomolecules. The measured SERS spectra from six different batches were subjected to a support vector machine (SVM) to train classification models. The sensitivities

Needs and challenges for assessing the environmental impacts of engineered nanomaterials (ENMs)

• Michelle Romero-Franco,
• Hilary A. Godwin,
• Muhammad Bilal and
• Yoram Cohen

Beilstein J. Nanotechnol. 2017, 8, 989–1014, doi:10.3762/bjnano.8.101

α-((4-Cyanobenzoyl)oxy)-ω-methyl poly(ethylene glycol): a new stabilizer for silver nanoparticles

• Jana Lutze,
• Miguel A. Bañares,
• Marcos Pita,
• Andrea Haase,
• Andreas Luch and
• Andreas Taubert

Beilstein J. Nanotechnol. 2017, 8, 627–635, doi:10.3762/bjnano.8.67

• function of the pH value both for the free stabilizer and for the polymers bound to the surface of the silver nanoparticles using 1H NMR spectroscopy and zeta potential measurements. The polymer shows a high stability between pH 3 and 9. At pH 12 and higher the polymer coating is degraded over time

• anchors. Keywords: cyano anchor group; poly(ethylene glycol); polymer coating; silver nanoparticles; Introduction Nanoparticles (NPs), especially metal NPs such as gold and silver NPs (SNPs), are currently among the most popular research subjects and many particles have been suggested for applications

• are currently of high interest [4][5]. Arguably, the most common stabilizer for gold and silver nanoparticles is PEG and the most common anchor group is the thiol/thiolate group. As stated in the introduction, there may however be situations where the thiol group may be unwanted. The new stabilizer

Microfluidic setup for on-line SERS monitoring using laser induced nanoparticle spots as SERS active substrate

• Oana-M. Buja,
• Ovidiu D. Gordan,
• Nicolae Leopold,
• Andreas Morschhauser,
• Jörg Nestler and
• Dietrich R. T. Zahn

Beilstein J. Nanotechnol. 2017, 8, 237–243, doi:10.3762/bjnano.8.26

• substrate. Keywords: gold nanoparticles; malachite green; microfluidic setup; SERS; silver nanoparticles; Introduction Over the past decade special attention has been given to the investigation of hazardous environmental chemicals with impact on human health [1][2][3][4]. Surface-enhanced Raman scattering

• attached to a rough metallic surface of silver, gold, or copper [10]. While metallic substrates are available in different shapes and sizes [9], colloidal citrate-reduced silver nanoparticles, synthesized following the method by Lee and Meisel [11] under boiling conditions, are amongst the most common

• ][14][15][16][17][18][19][20], so far, for a successful experiment the procedures require the synthesis of the colloids and previous mixing of the analyte and the silver nanoparticles. This study focuses on the on-line SERS monitoring of malachite green (MG) as a model analyte. However, the detection

Influence of hydrofluoric acid treatment on electroless deposition of Au clusters

• Rachela G. Milazzo,
• Antonio M. Mio,
• Giuseppe D’Arrigo,
• Emanuele Smecca,
• Alessandra Alberti,
• Gabriele Fisichella,
• Filippo Giannazzo,
• Corrado Spinella and
• Emanuele Rimini

Beilstein J. Nanotechnol. 2017, 8, 183–189, doi:10.3762/bjnano.8.19

• papers dealing with dynamic coalescence of metal nanoparticles in liquids [34][35][36]. In a previous work, we found that silver nanoparticles are subjected to Smoluchowski [37] ripening in DHF solutions by increasing their size and decreasing their surface density. For the case of gold nanoparticles on

Surface-enhanced infrared absorption studies towards a new optical biosensor

• Lothar Leidner,
• Julia Stäb,
• Jennifer T. Adam and
• Günter Gauglitz

Beilstein J. Nanotechnol. 2016, 7, 1736–1742, doi:10.3762/bjnano.7.166

• nanoparticles. According to Yang and Griffiths [12], the ideal substrate for SEIRA is a thin film of isolated nanoparticles distributed over a suitable infrared transparent substrate. They report enhancement factors of approximately 100 for silver nanoparticles on a germanium substrate. An interesting approach

• . The deposition of the water molecules leads to an increase of water absorption features due to adsorption of water molecules to the nanoparticle layer on top of the ATR waveguide. In the current work, water absorption spectra have been studied under the influence of silver nanoparticles present in an

• solution of 50 nm silver nanoparticles, the typical water features appear (a combination of water stretching and bending overtone bands). The signal increases and after about 90 min reaches its equilibrium (green line). 24 hours later, equilibrium is still preserved. After the addition of 10× concentrated

Hydrophilic silver nanoparticles with tunable optical properties: application for the detection of heavy metals in water

• Paolo Prosposito,
• Federico Mochi,
• Erica Ciotta,
• Mauro Casalboni,
• Fabio De Matteis,
• Iole Venditti,
• Laura Fontana,
• Giovanna Testa and
• Ilaria Fratoddi

Beilstein J. Nanotechnol. 2016, 7, 1654–1661, doi:10.3762/bjnano.7.157

• , University of Rome Sapienza, Rome, P.le A. Moro 5, 00187, Italy 10.3762/bjnano.7.157 Abstract Due their excellent chemo-physical properties and ability to exhibit surface plasmon resonance, silver nanoparticles (AgNPs) have become a material of choice in various applications, such as nanosensors, electronic

• devices, nanobiotechnology and nanomedicine. In particular, from the environmental monitoring perspective, sensors based on silver nanoparticles are in great demand because of their antibacterial and inexpensive synthetic method. In the present study, we synthesized AgNPs in water phase using silver

• AgNPs show good response to nickel (II) and presented good sensibility properties for the detection of low amount of ions in water in the working range of 1.0–0.1 ppm. Keywords: heavy metal sensor; nickel (II); optical materials; optical sensors; silver nanoparticles; Introduction Nanomaterials have

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

• . In this work, we demonstrate structural colour in a photonic crystal device comprised of alternating layers of silver nanoparticles and titanium dioxide nanoparticles, exhibiting spectral shifts of around 10 nm for an applied voltage of only 10 V. The accumulation of charge at the metal/dielectric

• evidence of structural colour tuning with an electric field in a one-dimensional photonic crystal made of alternating layers of silver nanoparticles and titanium dioxide nanoparticles. We have observed a blue shift of about 10 nm with an applied voltage of 10 V. We give an interpretation of the phenomenon

• nanoparticles and titanium dioxide nanoparticles deposited on top of an indium tin oxide (ITO) substrate. A scheme of the photonic crystal is shown in Figure 1. The silver nanoparticles have a diameter of about 50 nm, while the TiO2 nanoparticles are smaller than 15 nm. The surface topography and phase atomic

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

• triggered or directed by solution conditions such as temperature, illumination, pH and metal ion concentration [21]. Amongst the various self-assembled nanostructures, silver nanoparticles (AgNPs) are of great significance due to their sharp plasmon resonance, the antimicrobial function and a distinguished

• AgNPs modified by increasing amounts of the three H-bonding ligands: cysteamine, dithiothreitol (DTT) and cysteine. All spectra show a band at 398–410 nm, corresponding to the expected local plasmon resonance for spherical silver nanoparticles of this size. With the addition of a ditopic ligand, this

• -defined, distinct longitudinal band implies that the silver nanoparticles are forming anisotropic aggregates. For cysteine and DTT, at very high ligand-to-nanoparticle ratios, the transverse and longitudinal collapse into a single very broad resonance, which indicates a loss of structural anisotropy in

Templated green synthesis of plasmonic silver nanoparticles in onion epidermal cells suitable for surface-enhanced Raman and hyper-Raman scattering

• Marta Espina Palanco,
• Klaus Bo Mogensen,
• Marina Gühlke,
• Zsuzsanna Heiner,
• Janina Kneipp and
• Katrin Kneipp

Beilstein J. Nanotechnol. 2016, 7, 834–840, doi:10.3762/bjnano.7.75

• affiliation: Philips Biocell, Gydevang 42, 3450 Allerød, Denmark Humboldt Universität zu Berlin, 12489 Berlin, Germany 10.3762/bjnano.7.75 Abstract We report fast and simple green synthesis of plasmonic silver nanoparticles in the epidermal cells of onions after incubation with AgNO3 solution. The biological

• the extracellular matrix provides a biological template for the growth of plasmonic nanostructures. This is indicated by red glowing images of extracellular spaces in dark field microscopy of onion layers a few hours after AgNO3 exposure due to the formation of silver nanoparticles. Silver

• demonstrate a templated green preparation of enhancing plasmonic nanoparticles and suggest a new route to deliver silver nanoparticles as basic building blocks of plasmonic nanosensors to plants by the uptake of solutions of metal salts. Keywords: biotemplates; green preparation; onion; plasmonic

Tight junction between endothelial cells: the interaction between nanoparticles and blood vessels

• Yue Zhang and
• Wan-Xi Yang

Beilstein J. Nanotechnol. 2016, 7, 675–684, doi:10.3762/bjnano.7.60

• inhibited (79%) by silver nanoparticles (2–6 nm) [80]. Also, AuNPs have the ability to prevent vascular endothelial growth factor (VEGF)- and interleukin-1 beta (IL-1β)-induced proliferation and migration in bovine retinal pigment epithelial cells (BRPEs) through the suppression of the Src kinase pathway

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

• and modeled in [6] for nanocomposites with silver nanoparticles and different distances between ions and silver nanoparticles in the range between 10 and 300 nm. Indeed, as it follows from our results (Figure 7) enhancement of the luminescence output was observed in nanocomposites with AuNPs. This

Antibacterial activity of silver nanoparticles obtained by pulsed laser ablation in pure water and in chloride solution

• Brunella Perito,
• Emilia Giorgetti,
• Paolo Marsili and
• Maurizio Muniz-Miranda

Beilstein J. Nanotechnol. 2016, 7, 465–473, doi:10.3762/bjnano.7.40

• Physics “Enrico Fermi”, University of Pisa, Largo Bruno Pontecorvo 3, Pisa, 56127, Italy, Department of Chemistry “Ugo Schiff”, University of Florence, Via della Lastruccia 3, Sesto Fiorentino (FI) 50019, Italy 10.3762/bjnano.7.40 Abstract Silver nanoparticles (AgNPs) have increasingly gained importance

• particular, silver nanoparticles (AgNPs) have increasingly gained importance as promising new antimicrobial agents with application in several biomedical fields, in water and air filtration, as well as in conservation of cultural heritage [11][12][13][14]. Although the mode of action of AgNPs against

• in the presence of LiCl would be less oxidized [32]. In addition, the plasmon bands of the silver nanoparticles obtained by ps ablation in both pure water and LiCl solution appear significantly red-shifted compared to those observed for colloids obtained by ns ablation. This result could also be

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

• currently in use for medical purposes [3], for example silver nanoparticles (AgNPs) and superparamagnetic iron oxide nanoparticles (SPIONs). AgNPs are exploited in medicine for biocidal therapy owing to their antibacterial, antifungal, antiviral, and anti-inflammatory properties. In addition, they attract

• bromide (CTA), poly(vinylpyrrolidone) (PVP), poly(L-lysine) (PLL), bovine serum albumin (BSA), Brij 35 (Brij), Tween 20 (Tween) and D-mannose (MAN). Silver nanoparticles coated with sodium bis(2-ethylhexyl) sulfosuccinate (AOTAgNP), cetyltrimethylammonium bromide (CTAAgNP), poly(vinylpyrrolidone) (PVPAgNP

• redispersed in ultrapure water by sonification. Silver nanoparticles directly conjugated to bovine serum albumin (BSAAgNPs) were prepared as follows: 7.6 mL of 50 mM AgNO3 was added dropwise under stirring to 33 mL of ultrapure water containing dissolved 90 mg of BSA. Then, sodium borohydride (1 mL, 0.397 M

Linear and nonlinear optical properties of hybrid metallic–dielectric plasmonic nanoantennas

• Mario Hentschel,
• Bernd Metzger,
• Bastian Knabe,
• Karsten Buse and
• Harald Giessen

Beilstein J. Nanotechnol. 2016, 7, 111–120, doi:10.3762/bjnano.7.13

• from metal-island films and microstructured silver films were shown to be related to the enhanced local near-field [22]. Gold and silver nanoparticles in water were shown to enable optical phase conjugation [23][24] with an order of magnitude enhanced optical Kerr coefficient when exciting the

Controlled graphene oxide assembly on silver nanocube monolayers for SERS detection: dependence on nanocube packing procedure

• Martina Banchelli,
• Bruno Tiribilli,
• Roberto Pini,
• Luigi Dei,
• Paolo Matteini and
• Gabriella Caminati

Beilstein J. Nanotechnol. 2016, 7, 9–21, doi:10.3762/bjnano.7.2

• (AFM) measurements of the resulting samples revealed that a similar surface coverage was achieved with both procedures but with a different distribution of silver nanoparticles. In the GO covered LB film, the AgNC distribution is characterized by densely packed regions alternating with empty surface

• GO. Although fabrication of GO-covered nanoparticles has been explored using several methods such as voltammetric co-reduction [33], formation of composite graphene oxide/PAMAM–silver nanoparticles through self-assembly followed by microwave irradiation [34] and GO drop-casting onto amino

• ] proposed to assemble silver nanoparticles to graphene oxide sheets employing electrostatic interactions and a polymer, as adhesive agent, to impart greater stability against aggregation of AgNPs. Previous investigations are generally focused on spherical nanoparticles and only recently Fan et al. reported

Ultrastructural changes in methicillin-resistant Staphylococcus aureus induced by positively charged silver nanoparticles

• Dulce G. Romero-Urbina,
• Humberto H. Lara,
• J. Jesús Velázquez-Salazar,
• M. Josefina Arellano-Jiménez,
• Eduardo Larios,
• Anand Srinivasan,
• Jose L. Lopez-Ribot and
• Miguel José Yacamán

Beilstein J. Nanotechnol. 2015, 6, 2396–2405, doi:10.3762/bjnano.6.246

• Abstract Silver nanoparticles offer a possible means of fighting antibacterial resistance. Most of their antibacterial properties are attributed to their silver ions. In the present work, we study the actions of positively charged silver nanoparticles against both methicillin-sensitive Staphylococcus

• aureus and methicillin-resistant Staphylococcus aureus. We use aberration-corrected transmission electron microscopy to examine the bactericidal effects of silver nanoparticles and the ultrastructural changes in bacteria that are induced by silver nanoparticles. The study revealed that our 1 nm average

• size silver nanoparticles induced thinning and permeabilization of the cell wall, destabilization of the peptidoglycan layer, and subsequent leakage of intracellular content, causing bacterial cell lysis. We hypothesize that positively charged silver nanoparticles bind to the negatively charged

Nanotechnology in the real world: Redeveloping the nanomaterial consumer products inventory

• Marina E. Vance,
• Todd Kuiken,
• Eric P. Vejerano,
• Sean P. McGinnis,
• Michael F. Hochella Jr.,
• David Rejeski and
• Matthew S. Hull

Beilstein J. Nanotechnol. 2015, 6, 1769–1780, doi:10.3762/bjnano.6.181

• in Standardization (ANEC), joined efforts to develop an inventory of “consumer products with nano-claims” available to consumers in Europe [10]. A new inventory was generated annually from 2009 to 2012, but the 2011 and 2012 versions focused exclusively on products containing silver nanoparticles

• . Titanium dioxide (TiO2), silicon dioxide, and zinc oxide are the most produced nanomaterials worldwide (on a mass basis) and the global annual production of silver nanoparticles represents only 2% of that of TiO2 [20][21]. However, silver nanoparticles are the most popular advertised nanomaterial in the

• compositions, silver is also the most frequently advertised nanomaterial component, with 207 products or 14.5% [11]. Silver nanoparticles are popular consumer product additives due to their well-documented antimicrobial properties [22]. Figure 3 shows how the availability of these major nanomaterial