Temperature-dependent breakdown of hydrogen peroxide-treated ZnO and TiO₂ nanoparticle agglomerates

• Sinan Sabuncu and
• Mustafa Çulha

Beilstein J. Nanotechnol. 2015, 6, 1897–1903, doi:10.3762/bjnano.6.193

• hot plate before analysis. DLS analysis of the hydroxylated ZnO and TiO2 NPs The hydrodynamic radius and zeta potential of the NPs in suspension were monitored using a Zetasizer NanoZS (Malvern, UK) instrument equipped with a 4 mW HeNe laser (633 nm). The hydroxylated ZnO or TiO2 NPs were added to

• the temperature. The suspension was placed into a folded capillary cell for zeta potential measurement and the zeta potential of the NPs was measured at 30 °C. All experiments were performed at least three times. Results and Discussion Representative TEM images of the ZnO and TiO2 NPs are provided in

• Figure 1. As can be seen, both types of NPs are composed of NPs with a range of sizes. The average size of the ZnO and TiO2 NPs were 98 and 18 nm, respectively. Change in zeta potential after NP hydroxylation The zeta potential (ζ) of the NPs provides information about the surface charge of the particle

NanoE-Tox: New and in-depth database concerning ecotoxicity of nanomaterials

• Katre Juganson,
• Angela Ivask,
• Irina Blinova,
• Monika Mortimer and
• Anne Kahru

Beilstein J. Nanotechnol. 2015, 6, 1788–1804, doi:10.3762/bjnano.6.183

• , primary size, possible impurities, surface area and other observations, and the test environment-specific characteristics are: media, size, dissolution and zeta potential (Supporting Information File 2). Figure 4 illustrates the distribution of the data on ENM characteristics in NanoE-Tox database

Template-controlled mineralization: Determining film granularity and structure by surface functionality patterns

• Nina J. Blumenstein,
• Jonathan Berson,
• Stefan Walheim,
• Petia Atanasova,
• Johannes Baier,
• Joachim Bill and
• Thomas Schimmel

Beilstein J. Nanotechnol. 2015, 6, 1763–1768, doi:10.3762/bjnano.6.180

• (data not shown). The investigation of the suspensions from the reaction solution by zeta potential measurements revealed that the particles possess a potential of +22.0 mV at pH 6.7 [26]. Since the pH of the reaction solution is around 5.3, the formed NPs are positively charged (Figure 2). The zeta

• potential of the amino-functionalized SAM is charged slightly positive during the reaction [28][29] due to protonation of the amino groups (–NH3+) at this pH. Additionally, a Stern layer is present, which is formed by negatively charged counterions [29][30]. The particles in solution can interact with these

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

• molecules in in vivo and in vitro microenvironments. Hence, the surface charge of the nanoparticles was investigated by means of zeta potential analysis. As shown in Table 1, the uncoated Fe3O4 nanoparticle surface charge was about −42.7, which changed to +41.5 and +23.6 after coating with TMC and chitosan

• onto the polymer/Fe3O4 nanoparticles also influenced the surface charge of the resulting nanoparticles. The results of the zeta potential analysis in Table 1 show that the surface charge of the final products are −31.6 for Au/TMC/Fe3O4 nanoparticles and −6.2 for Au/chitosan/Fe3O4 nanoparticles due to

• effect of different concentrations of Au/TMC/Fe3O4 nanoparticles on cell viability as assessed by MTT assay. Size evaluation via TEM, XRD, DLS and zeta potential analysis of the synthesized nanoparticles. Acknowledgements This research was supported by the Endocrinology and Metabolism Research Institute

The eNanoMapper database for nanomaterial safety information

• Nina Jeliazkova,
• Charalampos Chomenidis,
• Philip Doganis,
• Bengt Fadeel,
• Roland Grafström,
• Barry Hardy,
• Janna Hastings,
• Markus Hegi,
• Vedrin Jeliazkov,
• Nikolay Kochev,
• Pekka Kohonen,
• Cristian R. Munteanu,
• Haralambos Sarimveis,
• Bart Smeets,
• Pantelis Sopasakis,
• Georgia Tsiliki,
• David Vorgrimmler and
• Egon Willighagen

Beilstein J. Nanotechnol. 2015, 6, 1609–1634, doi:10.3762/bjnano.6.165

• similarity and substructure search enhances the data exploration capabilities of the system (e.g., finding nanoparticles with similar coatings). The data exploration is also supported by REST API calls retrieving data summaries (e.g., number of zeta potential entries) and endpoint prefix queries, allowing

• sizes and visualizes it with d3.js, resulting in Figure 17. A variation of the second example shows a scatter plot of the zeta potential values against nanomaterial sizes. Here, the same approach is used and the bits of information are aggregated in a global variable. The results are shown in Figure 18

Influence of surface chemical properties on the toxicity of engineered zinc oxide nanoparticles to embryonic zebrafish

• Zitao Zhou,
• Jino Son,
• Bryan Harper,
• Zheng Zhou and
• Stacey Harper

Beilstein J. Nanotechnol. 2015, 6, 1568–1579, doi:10.3762/bjnano.6.160

• membrane proteins [37]. Although zeta potential is known to be crucial to biological response [38]; it’s dependent on the environment in which it is measured and thus is not an intrinsic feature of the NP and thus was omitted from the model. Following PCA, the ordinary kriging (OK) method was applied to

• with biological membranes may drive toxicity more than the size of the particle itself. NP agglomeration in aquatic environments often occurs and can be influenced by physicochemical properties of the particle surface and environmental factors affecting the zeta potential [27][45][46]. Therefore, it is

Using natural language processing techniques to inform research on nanotechnology

• Nastassja A. Lewinski and
• Bridget T. McInnes

Beilstein J. Nanotechnol. 2015, 6, 1439–1449, doi:10.3762/bjnano.6.149

• the numeric values and dendrimer property terms. The entities associated with PAMAM were based on the NanoParticle Ontology and included: (1) hydrodynamic diameter, (2) particle diameter, (3) molecular weight, (4) zeta potential, (5) cytotoxicity, (6) IC50, (7) cell viability, (8) encapsulation

Peptide-equipped tobacco mosaic virus templates for selective and controllable biomineral deposition

• Klara Altintoprak,
• Axel Seidenstücker,
• Alexander Welle,
• Sabine Eiben,
• Petia Atanasova,
• Nina Stitz,
• Alfred Plettl,
• Joachim Bill,
• Hartmut Gliemann,
• Holger Jeske,
• Dirk Rothenstein,
• Fania Geiger and
• Christina Wege

Beilstein J. Nanotechnol. 2015, 6, 1399–1412, doi:10.3762/bjnano.6.145

• applied: both samples did not migrate into the gel phase to a sufficient extent. Zeta potential measurement The zeta potentials (ZPs) of TMV–Lys nanorods and their derivatives were determined using a Malvern NanoSizer at a virus particle concentration of 0.5 mg/mL in ultrapure water (ddH2O) and in 30 mM

• buffer (10 mM SPP pH 7.2, 0.1% (w/v) bromophenol blue, 10% glycerol) were applied per lane. TMV bands were stained with Coomassie Brilliant Blue R250. Zeta potential determination and charge calculation The zeta potential was measured with a Malvern Zetasizer Nano ZS (Malvern Instruments, Worcestershire

• , UK) using disposable folded cuvettes. The Smoluchowski approximation was used according to instrument settings to convert the electrophoretic mobility to a zeta potential. The experiments consisted of 30 runs per measurement. All experiments were conducted in triplicate. The zeta potential was

PLGA nanoparticles as a platform for vitamin D-based cancer therapy

• Maria J. Ramalho,
• Joana A. Loureiro,
• Bárbara Gomes,
• Manuela F. Frasco,
• Manuel A. N. Coelho and
• M. Carmo Pereira

Beilstein J. Nanotechnol. 2015, 6, 1306–1318, doi:10.3762/bjnano.6.135

• cell growth, cell cycle arrest and morphological changes. Results Nanoparticle physicochemical properties PLGA NPs were prepared by a single emulsion solvent evaporation method and stabilized with Pluronic®F127. The obtained results for mean the diameter, polydispersity index (PDI) and zeta potential

• for the unloaded PLGA NPs are shown in Table 1. According to the literature, the PLGA NPs size is found to be in the range of 100 to 250 nm [20]. The prepared unloaded NPs are within the expected range, exhibiting a mean diameter of 172 ± 4 nm, and presenting a zeta potential value of −38 mV: negative

• , as expected, due to their carboxylic end groups (Table 1). The single emulsion solvent evaporation method allowed the encapsulation of vitamin D3 in the PLGA NPs. The obtained results for the mean diameter, PDI, zeta potential, encapsulation efficiency and loading capacity values for the PLGA NPs

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

• electrostatic stability of the particles. Note that the variation of the zeta potential is probably within the range of the experimental noise. Table 1shows all size-related data of the alloyed nanoparticles. The experimental molar compositions of the nanoparticles were examined by AAS. The silver and gold

• were performed at (A) 5 h, (B) 24 h, (C) and 72 h after the nanoparticle addition. The dotted lines indicate the viability of the control (untreated cells). Results of nanoparticle diameters determined from TEM, DCS and DLS (by number) and zeta potential measurements of PVP-functionalized Ag/Au

Protein corona – from molecular adsorption to physiological complexity

• Lennart Treuel,
• Dominic Docter,
• Michael Maskos and
• Roland H. Stauber

Beilstein J. Nanotechnol. 2015, 6, 857–873, doi:10.3762/bjnano.6.88

• the ε-amino group of lysine with succinic anhydride, Treuel et al. [4], turned these positively charged groups into negatively charged carboxylate functions, obtaining succinylated HSA (HSAsuc). In addition to the surface charge distribution, this succinylation changed the overall zeta potential of

• aminated HSA molecule (HSAam). This amination expectedly decreased the magnitude of the zeta potential of native HSA, (−10.5 ± 1.3) mV, to (−6.1 ± 0.4) mV (in PBS at pH 7.4). DLS measurements confirmed that the protein size remained essentially unchanged after all chemical modifications and the overall

Influence of gold, silver and gold–silver alloy nanoparticles on germ cell function and embryo development

• Ulrike Taylor,
• Daniela Tiedemann,
• Christoph Rehbock,
• Wilfried A. Kues,
• Stephan Barcikowski and
• Detlef Rath

Beilstein J. Nanotechnol. 2015, 6, 651–664, doi:10.3762/bjnano.6.66

• another safety feature was noted: Compared to somatic cells which readily incorporate nanoparticles [58][59][60], the sperm plasma membrane, prior to acrosome reaction, seems literally impenetrable for any nanoparticles we tested which encompassed ligand-free AuNP (diameter 10.8 nm, Zeta potential −25 mV

• ) and oligonucleotide conjugated AuNP (diameter 7.3 nm, 94 biomolecules per particle, Zeta potential −32 mV) which were tested by using bovine sperm, as well as bovine serum albumin (BSA) coated gold (diameter 6–20 nm), silver (diameter 11 nm; AgNP) and various gold silver alloy nanoparticles (silver

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

• temperature. The magnetization curve proved that the magnetic NPs retained their superparamagnetic property in the silica sphere, attaining a saturation magnetization value of 3.21 emu·g−1. It was found that after amine functionalization, the corresponding zeta potential peaks shifted from negative to

Pulmonary surfactant augments cytotoxicity of silica nanoparticles: Studies on an in vitro air–blood barrier model

• Jennifer Y. Kasper,
• Lisa Feiden,
• Maria I. Hermanns,
• Christoph Bantz,
• Michael Maskos,
• Ronald E. Unger and
• C. James Kirkpatrick

Beilstein J. Nanotechnol. 2015, 6, 517–528, doi:10.3762/bjnano.6.54

• directly the production of reactive oxygen species. This would explain the increased toxicity for aSNP–plain in combination with lung surfactant, but also for aSNP–NH2, taking into account the zeta potential of all three aSNPs (aSNP–plain: −23.4 mV; –NH2: −24.6 mV and –COOH: −29.3 mV, data kindly provided

• by the manufacturer micromod GmbH). aSNP–NH2 retained a negative “netto” surface charge according to their zeta potential, although it is supposed to display a positive charge on the basis of the amino-groups. This phenomenon was already described by Tenzer et al., who concluded that according to the

• zeta potential the functionalization of similar aSNPs with amino groups was not saturated so as to mask negative charge of the surface silanols [38]. In terms of chemistry aSNP–NH2 and –COOH have remaining silanol groups to a similar extent. Since aSNP–COOH (with a similar amount of free silanol groups

Tailoring the ligand shell for the control of cellular uptake and optical properties of nanocrystals

• Johannes Ostermann,
• Christian Schmidtke,
• Christopher Wolter,
• Jan-Philip Merkl,
• Hauke Kloust and
• Horst Weller

Beilstein J. Nanotechnol. 2015, 6, 232–242, doi:10.3762/bjnano.6.22

• indicates, that the functional groups embedded on the outer part of the micelle do not interact significantly with the surface of the inorganic NP. In contrast, the surface charge was influenced by the end-group of the polymer as it was expected. This could be proven by zeta potential measurements in

• , MeOH, Amberlite® IR120 (hydrogen form). Reproduced with permission from [30]. Copyright 2013 The Royal Society of Chemistry. Zeta potential of PI-b-PEG encapsulated QDs with different end groups in deionized water. Reproduced with permission from [30]. Copyright 2013 The Royal Society of Chemistry

Caveolin-1 and CDC42 mediated endocytosis of silica-coated iron oxide nanoparticles in HeLa cells

• Nils Bohmer and
• Andreas Jordan

Beilstein J. Nanotechnol. 2015, 6, 167–176, doi:10.3762/bjnano.6.16

• ). These modifications resulted in different physicochemical properties referring to SPIONs surface charge and their size distribution under physiological conditions (Table 1). The primary particle size was determined by transmission electron microscopy (EM906, Zeiss). The zeta potential and the average

The fate of a designed protein corona on nanoparticles in vitro and in vivo

• Denise Bargheer,
• Julius Nielsen,
• Gabriella Gébel,
• Markus Heine,
• Sunhild C. Salmen,
• Roland Stauber,
• Horst Weller,
• Joerg Heeren and
• Peter Nielsen

Beilstein J. Nanotechnol. 2015, 6, 36–46, doi:10.3762/bjnano.6.5

• reported to play significant roles [1][2][3][4][5][6][7]. A small size, neutral or negative zeta potential, and extended PEGylation of the surface material are correlated with increased circulation time in blood after intravenous (i.v.) injection [4][6]. One important implication is that NP upon contact

Interaction of dermatologically relevant nanoparticles with skin cells and skin

• Annika Vogt,
• Fiorenza Rancan,
• Sebastian Ahlberg,
• Berouz Nazemi,
• Chun Sik Choe,
• Maxim E. Darvin,
• Sabrina Hadam,
• Ulrike Blume-Peytavi,
• Kateryna Loza,
• Jörg Diendorf,
• Matthias Epple,
• Christina Graf,
• Eckart Rühl,
• Martina C. Meinke and
• Jürgen Lademann

Beilstein J. Nanotechnol. 2014, 5, 2363–2373, doi:10.3762/bjnano.5.245

• heavily aggregated but still taken up into cells in large numbers. However, N-(6-aminohexyl)-aminopropyltrimethoxysilane (AHAPS)-functionalized particles, which had also a highly positive zeta-potential due to the amino groups but did not aggregate in cell culture media were also found in large numbers in

• microscope (Zeiss EM906). Detection of silver particle-mediated production of reactive oxygen specimen by EPR spectroscopy: The PVP-coated silver nanoparticles were prepared as described in Loza et al. [46]. They had a negative zeta-potential of −20 mV and a diameter of the metallic core of 70 nm. They were

Liquid-phase exfoliated graphene: functionalization, characterization, and applications

• Mildred Quintana,
• Jesús Iván Tapia and
• Maurizio Prato

Beilstein J. Nanotechnol. 2014, 5, 2328–2338, doi:10.3762/bjnano.5.242

• the square of the zeta potential of the surfactant-coated sheets. This means that the concentration is proportional to the magnitude of the electrostatic potential barrier, which prevents graphene π–π stabilization. In contrast, for non-ionic surfactants, the dispersed graphene concentration increased

Nanobioarchitectures based on chlorophyll photopigment, artificial lipid bilayers and carbon nanotubes

• Marcela Elisabeta Barbinta-Patrascu,
• Stefan Marian Iordache,
• Ana Maria Iordache,
• Nicoleta Badea and
• Camelia Ungureanu

Beilstein J. Nanotechnol. 2014, 5, 2316–2325, doi:10.3762/bjnano.5.240

• structures with single-walled carbon nanotubes. Different biophysical methods were employed to characterize these biohybrids such as: UV–vis absorption and emission spectroscopy, zeta potential measurements, AFM and chemiluminescence techniques. The designed, carbon-based biohybrids exhibited good physical

• stability, good antioxidant and antimicrobial properties, and could be used as biocoating materials. As compared to the cholesterol-free samples, the cholesterol-containing hybrid structures demonstrated better stability (i.e., their zeta potential reached the value of −36.4 mV), more pronounced oxygen

• excitation and emission polarizers, respectively, and G, the instrumental grating factor, is defined as the ratio of the sensitivities of the detection system for vertically and horizontally polarized light [26]. Zeta potential determination The measurement of the electrokinetic potential is used to assess

Nanoencapsulation of ultra-small superparamagnetic particles of iron oxide into human serum albumin nanoparticles

• Matthias G. Wacker,
• Mahmut Altinok,
• Stephan Urfels and
• Johann Bauer

Beilstein J. Nanotechnol. 2014, 5, 2259–2266, doi:10.3762/bjnano.5.235

• desolvation in absence and in presence of USPIO. The particle size and zeta potential observed by dynamic light scattering (DLS) measurements significantly increased with the amount of iron oxide particles present during the desolvation process (ANOVA). Particles with the highest content of iron oxide were

• shown). A pH of 8.5 was optimal for all tested USPIO concentrations. Interestingly, zeta potential increased with rising amounts of USPIO present during the preparation process. A total value of −20 mV was not exceeded. Since similar values have been reported for stable unmodified HSA particles [15] and

• , polydispersity, and zeta potential were determined by dynamic light scattering using a Malvern Zetasizer Nano (Malvern Instruments, Malvern, UK). For determination of the zeta potential a Malvern Dip Cell was used. All samples were diluted 1:50 with purified water before the measurement. The nanoparticle content

Effect of silver nanoparticles on human mesenchymal stem cell differentiation

• Christina Sengstock,
• Jörg Diendorf,
• Matthias Epple,
• Thomas A. Schildhauer and
• Manfred Köller

Beilstein J. Nanotechnol. 2014, 5, 2058–2069, doi:10.3762/bjnano.5.214

• atomic absorption spectroscopy (AAS, Thermo Electron Corporation, M-Series). The hydrodynamic diameter and the zeta-potential of the dispersed particles were measured by dynamic light scattering (DLS) using a Malvern Zetasizer Nano ZS. The z-average value was used as the average particle diameter. The

Effects of surface functionalization on the adsorption of human serum albumin onto nanoparticles – a fluorescence correlation spectroscopy study

• Pauline Maffre,
• Stefan Brandholt,
• Karin Nienhaus,
• Li Shang,
• Wolfgang J. Parak and
• G. Ulrich Nienhaus

Beilstein J. Nanotechnol. 2014, 5, 2036–2047, doi:10.3762/bjnano.5.212

• centered at ≈580 nm). The results from multiple zeta potential and DLS measurements, that is, the zeta potential and number distributions, were individually fitted with Gaussian functions and then averaged to determine the zeta potentials and hydrodynamic diameters of the particles. HSA modification

• of a perhaps incomplete QD coating during protein adsorption. The complete reversibility of the corona formation on DHLA–QDs (see below) suggests that protein denaturation does not occur. A problem with incomplete surface coverage with DHLA is also highly unlikely in view of the negative zeta

• potential and the excellent colloidal stability of the DHLA-coated NPs. Zwitterionic surfaces, however, are famous for their hydrophobicity, protein adsorption resistance and anti-fouling properties, which strongly argues against a destabilizing effect of DPA-QDs [51]. Of note is that our measured ΔRH value

PVP-coated, negatively charged silver nanoparticles: A multi-center study of their physicochemical characteristics, cell culture and in vivo experiments

• Sebastian Ahlberg,
• Alexandra Antonopulos,
• Jörg Diendorf,
• Ralf Dringen,
• Matthias Epple,
• Rebekka Flöck,
• Wolfgang Goedecke,
• Christina Graf,
• Nadine Haberl,
• Jens Helmlinger,
• Fabian Herzog,
• Frederike Heuer,
• Stephanie Hirn,
• Christian Johannes,
• Stefanie Kittler,
• Manfred Köller,
• Katrin Korn,
• Wolfgang G. Kreyling,
• Fritz Krombach,
• Jürgen Lademann,
• Kateryna Loza,
• Eva M. Luther,
• Marcelina Malissek,
• Martina C. Meinke,
• Daniel Nordmeyer,
• Anne Pailliart,
• Jörg Raabe,
• Fiorenza Rancan,
• Barbara Rothen-Rutishauser,
• Eckart Rühl,
• Carsten Schleh,
• Andreas Seibel,
• Christina Sengstock,
• Lennart Treuel,
• Annika Vogt,
• Katrin Weber and
• Reinhard Zellner

Beilstein J. Nanotechnol. 2014, 5, 1944–1965, doi:10.3762/bjnano.5.205

• main text. 10.3762/bjnano.5.205 Abstract PVP-capped silver nanoparticles with a diameter of the metallic core of 70 nm, a hydrodynamic diameter of 120 nm and a zeta potential of −20 mV were prepared and investigated with regard to their biological activity. This review summarizes the physicochemical

• zeta potential of −20 mV and a metallic core diameter of about 70 nm. All concentrations given refer to the amount of silver. This review article summarizes the results of all groups who participated in this study. Synthesis and colloid-chemical characterization of silver nanoparticles The synthesis of

The surface properties of nanoparticles determine the agglomeration state and the size of the particles under physiological conditions

• Christoph Bantz,
• Olga Koshkina,
• Thomas Lang,
• Hans-Joachim Galla,
• C. James Kirkpatrick,
• Roland H. Stauber and
• Michael Maskos

Beilstein J. Nanotechnol. 2014, 5, 1774–1786, doi:10.3762/bjnano.5.188

• TEM, one is not able to detect agglomerates due to the fact that the arrangement of the particles is influenced by the preparation. Zeta potential (ZP) determination in water containing small amounts of salt (5 mM NaBr) yielded a value of −40 mV, which clearly shows the negative surface charge that is

• responsible for the colloidal stability of the dispersion. Generally, the absolute value of the zeta potential decreases under conditions of high salinity, which are predominant in cell culture medium. For example, for NexSil20, a zeta potential value of −20 mV is found. However, under conditions of

• physiological salinity, zeta potential determinations based on electrophoretic mobility measurements should be treated with great care. As they are influenced by a multitude of factors, such as surface charge, salinity and by the interactions that are present in the colloid, the applied models to derive zeta