Synthesis and functionalization of NaGdF₄:Yb,Er@NaGdF₄ core–shell nanoparticles for possible application as multimodal contrast agents

• Dovile Baziulyte-Paulaviciene,
• Vitalijus Karabanovas,
• Marius Stasys,
• Greta Jarockyte,
• Vilius Poderys,
• Simas Sakirzanovas and
• Ricardas Rotomskis

Beilstein J. Nanotechnol. 2017, 8, 1815–1824, doi:10.3762/bjnano.8.183

• (Figure 3c), indicating that the Tween 80 was successfully coated onto the UCNPs. Additionally, dynamic light scattering (DLS) was employed to measure the hydrodynamic diameter of Tween-coated UCNPs in the cell culture medium as well as their surface zeta potential. The measured mean hydrodynamic diameter

• of the Tween-coated core NaGdF4:Yb,Er UCNPs was 38 nm and the core–shell NaGdF4:Yb,Er@NaGdF4 particles was 48 nm. The zeta potential of Tween 80-coated core nanoparticles was about 26 mV and for core–shell nanoparticles it was slightly higher at about 33 mV. More detailed information about the DLS

• equations: where ni and Di are the number and diameter of the particle, respectively. Dynamic light scattering (DLS) was used to determine the hydrodynamic particle diameter and zeta potential. These experiments were performed with Brookhaven ZetaPALS zeta potential analyzer (Brookhaven Instruments, USA

Uptake and intracellular accumulation of diamond nanoparticles – a metabolic and cytotoxic study

• Antonín Brož,
• Lucie Bačáková,
• Pavla Štenclová,
• Alexander Kromka and
• Štěpán Potocký

Beilstein J. Nanotechnol. 2017, 8, 1649–1657, doi:10.3762/bjnano.8.165

• NDs exhibited rapid penetration into the cells from the beginning of the cultivation period, and also rapid cell congestion and a rapid reduction in viability. These findings are discussed with reference to relevant properties of NDs such as surface chemical bonds, zeta potential and nanoparticle

• influencing the bulk of the NDs (formation of vacancies, and N-V sites supported by high-temperature annealing in vacuum) [39]. This was confirmed by the fact that there was no obvious difference in the FTIR spectra between the MR-18 sample and the AR-40 sample. The zeta potential of MR-type NDs were negative

• , typically in the range of −20 to −40 mV [40][41], comparable with the −37 mV zeta potential value of the AR-40 sample. The stock concentration of AR-40 did not allow us to test the effect of the highest ND concentration (1000 µg/mL, 300 µg/cm2). Next, we compared the influence of surface treatment by

Development of an advanced diagnostic concept for intestinal inflammation: molecular visualisation of nitric oxide in macrophages by functional poly(lactic-co-glycolic acid) microspheres

• Kathleen Lange,
• Christian Lautenschläger,
• Maria Wallert,
• Stefan Lorkowski,
• Andreas Stallmach and
• Alexander Schiller

Beilstein J. Nanotechnol. 2017, 8, 1637–1641, doi:10.3762/bjnano.8.163

• ) (PLGA). PLGA microspheres loaded with NO550 dye were prepared through a modified solvent-evaporation method. Microparticles were characterized by a mean hydrodynamic diameter of 3000 nm, zeta potential of −26.000 ± 0.351 mV and a PDI of 0.828 ± 0.298. Under abiotic conditions, NO release was triggered

• and reproducible process (for more experimental data please see Section 1 and Section 2 of Supporting Information File 1). The particles showed a mean hydrodynamic diameter of 3000 nm, a zeta potential of −26.000 ± 0.351 mV and a PDI of 0.828 ± 0.298. Furthermore, NO550-loaded microspheres were

• characterised by a slightly more irregular surface with small pores compared to blank microspheres (Figure 1). In contrast, blank microspheres showed a mean hydrodynamic diameter of 3000 nm, a zeta potential of −1.250 ± 0.132 mV and a PDI of 0.253 ± 0.042. The blank microspheres are similarly sized spherical

The effect of the electrical double layer on hydrodynamic lubrication: a non-monotonic trend with increasing zeta potential

• Dalei Jing,
• Yunlu Pan and
• Xiaoming Wang

Beilstein J. Nanotechnol. 2017, 8, 1515–1522, doi:10.3762/bjnano.8.152

• lubricant under the influence of the EDL shows a non-monotonic trend, changing from enhancement to attenuation with a gradual increase in the absolute value of the zeta potential. This non-monotonic hydrodynamic lubrication is dependent on the non-monotonic electroviscous effect of the lubricant generated

• lubrication; zeta potential; Introduction As one of the oldest techniques in modern engineering, lubrication is widely recognized and has inspired significant scientific interest [1][2][3][4]. The use of a layer of lubricant film, either in solid or fluid state, between frictional pairs can effectively

• the EDL on modifying the conventional Reynolds equation, analyzing the hydrodynamic lubrication. They found that the minimum lubricant film thickness increased with the increasing absolute value of zeta potential (an important parameter of EDL to manifest the surface charge at the solid–liquid

A nanocomplex of C₆₀ fullerene with cisplatin: design, characterization and toxicity

• Svitlana Prylutska,
• Svitlana Politenkova,
• Kateryna Afanasieva,
• Volodymyr Korolovych,
• Kateryna Bogutska,
• Andriy Sivolob,
• Larysa Skivka,
• Maxim Evstigneev,
• Viktor Kostjukov,
• Yuriy Prylutskyy and
• Uwe Ritter

Beilstein J. Nanotechnol. 2017, 8, 1494–1501, doi:10.3762/bjnano.8.149

• wavelength of 633 nm. The measurements were performed at a 173° scattering angle (NIBS technology). The autocorrelation function of the scattered light intensity was analyzed by the Malvern Zetasizer software. The zeta potential was measured with a Zetasizer Nano ZS (Malvern Ins. Ltd) using a universal dip

• cell in disposable cuvettes. The Smoluchowski approximation was used to convert the electrophoretic mobility to the zeta potential. AFM study The surface morphology of the particles was examined using atomic force microscopy (AFM). AFM images were collected using an Integra Spectra microscope (NTMDT

• previous study of C60+Cis complexation [39]. The zeta potential of the C60+Cis mixture measured in this work equals to −16.8 mV at room temperature. It is known from previous studies that C60 fullerene clusters not containing any guest molecules have a zeta potential equal to −23 mV in water solution [41

Development of polycationic amphiphilic cyclodextrin nanoparticles for anticancer drug delivery

• Gamze Varan,
• Juan M. Benito,
• Carmen Ortiz Mellet and
• Erem Bilensoy

Beilstein J. Nanotechnol. 2017, 8, 1457–1468, doi:10.3762/bjnano.8.145

• -formulation studies were used as a basis for selecting the suitable organic solvent and surfactant concentration for the novel polycationic cyclodextrin nanoparticles. The nanoparticles were then extensively characterized with particle size distribution, polydispersity index, zeta potential, drug loading

• PCX not only in the hydrophobic cavity but also between the long cationic aliphatic chains of the cyclodextrin as PCX and CD are co-nanoprecipitated during the preparation method. Table 4 shows the final mean particle size, PDI and zeta potential values of PCX-loaded amphiphilic CD nanoparticles. The

• therapy can be provided with lower drug dose. Zeta potential measurements indicate that 6OCaproβCD has a negative surface charge unlike the other formulations. In this study, PC βCDC6 has a strong positive surface charge owing to polycationic amino groups. This amphiphilic CD derivative was previously

Cationic PEGylated polycaprolactone nanoparticles carrying post-operation docetaxel for glioma treatment

• Cem Varan and
• Erem Bilensoy

Beilstein J. Nanotechnol. 2017, 8, 1446–1456, doi:10.3762/bjnano.8.144

• , the particle size increases in each emulsification step. In addition, double emulsion resulted in a significant difference in the zeta potential of nanoparticles (p < 0.05). The surface charge of blank nanoparticles prepared by double emulsification was closer to neutral charge as compared to those

• formation of an extra surfactant layer and this layer increases the particle size. Besides that, this surfactant layer probably covered the polymer surface and thus the zeta potential of the nanoparticles approached a more neutral value. To render a positive surface charge to blank PCL or mePEG-PCL

• that have a zeta potential value smaller than 30 are more stable and show reduced aggregation [68][69]. In vitro characterization of docetaxel-loaded nanoparticles According to the results of the pre-formulation studies, the final formulation parameters were determined and nanoparticles were prepared

Bright fluorescent silica-nanoparticle probes for high-resolution STED and confocal microscopy

• Isabella Tavernaro,
• Christian Cavelius,
• Henrike Peuschel and
• Annette Kraegeloh

Beilstein J. Nanotechnol. 2017, 8, 1283–1296, doi:10.3762/bjnano.8.130

• software ImageJ (Version: 1.45a; http://rsbweb.nih.gov/ij/). In brief, after background subtraction and adjustment of brightness and contrast the SEM or TEM images were converted to 8-bit binary images. Particle size diameter and shape were counted automatically. Zeta-potential measurements: The ζ

Evaluation of quantum dot conjugated antibodies for immunofluorescent labelling of cellular targets

• Jennifer E. Francis,
• David Mason and
• Raphaël Lévy

Beilstein J. Nanotechnol. 2017, 8, 1238–1249, doi:10.3762/bjnano.8.125

• protein adsorption and thus the formation of a protein corona [38]. Qdots with a zwitterionic surface have a zeta potential of near zero, are resistant to non-specific binding onto cells, and have a high colloidal stability [39]. Commercially available Qdot-Abs evaluated in this report were used in fixed

Nano-engineered skin mesenchymal stem cells: potential vehicles for tumour-targeted quantum-dot delivery

• Liga Saulite,
• Dominyka Dapkute,
• Karlis Pleiko,
• Ineta Popena,
• Simona Steponkiene,
• Ricardas Rotomskis and
• Una Riekstina

Beilstein J. Nanotechnol. 2017, 8, 1218–1230, doi:10.3762/bjnano.8.123

• Thermo Fisher Scientific, USA. QDs are composed of a CdSe core with a ZnS shell that are coated with amphiphilic polymers and functionalized with carboxylate. The QDs have an emission maximum at 655 nm. Xu et al. measured the hydrodynamic diameter of the nanoparticles to be 14.55 ± 4.157 nm and a zeta

• potential of −35.1 mV [60]. The stock solution is 8 µM in 50 mM borate, pH 9.0. Further preparations of the QD solution are described in each methodological part separately. QD uptake dynamics using flow cytometry To estimate the optimal QD concentration for uptake experiments, MSCs were seeded at a density

ZnO nanoparticles sensitized by CuInZn_xS_2+x quantum dots as highly efficient solar light driven photocatalysts

• Florian Donat,
• Serge Corbel,
• Halima Alem,
• Steve Pontvianne,
• Lavinia Balan,
• Ghouti Medjahdi and
• Raphaël Schneider

Beilstein J. Nanotechnol. 2017, 8, 1080–1093, doi:10.3762/bjnano.8.110

• peak fitting procedures and the areas of each component were modified according to classical Scofield sensitivity factors. The initial and final total organic carbon (TOC) content was determined using a Shimadzu TOC-VCSH analyzer to evaluate the degree of photomineralization. The zeta potential (ζ) of

• -equilibrated and N2-purged aqueous solutions. Supporting Information File 68: Additional figures. Acknowledgements This work is supported by the Agence Nationale pour la Recherche (ANR CD2I 2013, project PRUMOS). The authors thank Dr. Khalid Ferji (LCPM, Université de Lorraine) for the zeta potential

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

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

• from the observed changes in the optical absorption, plasmon band, zeta potential, DLS particle size distribution, as well as TEM and AFM surface morphology analysis. Circular dichroism studies also revealed that DNA-functionalized AuNP binding caused a conformational change in the DNA structure. Due

• 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

• AuNSs and AuNRs to be +22.8 mV and +26.16 mV, respectively. However, zeta potential of DNA was −16.84 mV and upon binding with AuNSs and AuNRs changed to +16.67 mV and +10.40 mV, respectively. It was observed that after DNA–AuNP binding, the resultant electronic charge of the Au–DNA nanocomposite is

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

• removed from the heating bath for DLS and zeta-potential measurements. Analytical methods Gel permeation chromatography. GPC measurements were done on two 300 × 8 mm2 PSS-GRAM (7 µm particles) columns with porosities of 102–103 Å in N-methyl-2-pyrrolidone (NMP + 0.5 wt % LiBr at 70 °C and a flow rate of

• synthesis, that is, no dilution or other sample processing was performed prior to Raman analysis. NMR spectroscopy. 1H NMR spectra were recorded on a Bruker Avance 300 MHz or 500 MHz spectrometer in D2O with TMS as an internal standard. Light scattering and zeta potential. The hydrodynamic diameter Rh and

Uptake of the proteins HTRA1 and HTRA2 by cells mediated by calcium phosphate nanoparticles

• Olga Rotan,
• Katharina N. Severin,
• Simon Pöpsel,
• Alexander Peetsch,
• Melisa Merdanovic,
• Michael Ehrmann and
• Matthias Epple

Beilstein J. Nanotechnol. 2017, 8, 381–393, doi:10.3762/bjnano.8.40

• temperature. Analytical methods Dynamic light scattering (DLS) and zeta potential determinations were performed with a Zetasizer Nano series instrument (Malvern Nano-ZS, laser: λ = 532 nm) using the Smoluchowski approximation and taking the data from the Malvern software without further correction. The

• (Table 2). All nanoparticles had a hydrodynamic diameter between 250 and 350 nm. The zeta potential reflects the corresponding charge of the polyelectrolyte polymer used for the stabilization (CMC: negative charge, PEI: positive charge) that indicates the colloidal stability of the nanoparticles in

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

• treatment induced a 5 nm red shift after the binding of anti-IgG. Moreover, the nanorods showed no aggregation as can be deduced from the lack of peak broadening and alteration of the spectra for all samples. Table S1 (Supporting Information File 1) presents a summary of the change in the zeta potential of

• 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

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

• only little with increasing concentration (Table S2, Supporting Information File 1). The zeta potential of 2h particles is about −30 ± 1 mV (Figure S5, Supporting Information File 1). The increase in temperature up to 50 °С is shown to result in the breaking of the particles of the short-chain

• about 1 and about 200 nm in diameter (Figure 6b). The former most likely correspond to SDS micelles, while the latter represent mixed structures of SDS and the isoindigo derivative. In the SDS–2a system an increase in zeta potential is observed (Figure 6c). According to our results and literature data

• [77][78], the zeta potential of SDS micelles is about −70 mV, while the mixed aggregates of SDS and 2a have a zeta potential of about −110 mV. In the case of compound 3, there is a decrease in the zeta potential of SDS micelles by ca. 20 mV. Most probably, 2a molecules are incorporated and dissolved

Template-controlled piezoactivity of ZnO thin films grown via a bioinspired approach

• Nina J. Blumenstein,
• Fabian Streb,
• Stefan Walheim,
• Thomas Schimmel,
• Zaklina Burghard and
• Joachim Bill

Beilstein J. Nanotechnol. 2017, 8, 296–303, doi:10.3762/bjnano.8.32

• zeta potential of SAMs with COOH- and SO3H-functional groups in dependence on the pH [40]. They found that the sulfonate SAM is more negatively charged (−115 mV) compared to the carboxylate one (−75 mV) at a pH of 9, which corresponds to the pH of the mineralization solution used in this study. This

• ions as can be seen from the pKa values reported by Rived et al. [43]. Therefore, it is probable that the surface charge of the used templates is lower in methanol than it could be expected from zeta potential measurements in water. Nevertheless, the polarity of the two templates is high enough to

Comparison of four functionalization methods of gold nanoparticles for enhancing the enzyme-linked immunosorbent assay (ELISA)

• Paula Ciaurriz,
• Fátima Fernández,
• Edurne Tellechea,
• Jose F. Moran and
• Aaron C. Asensio

Beilstein J. Nanotechnol. 2017, 8, 244–253, doi:10.3762/bjnano.8.27

• maintained until the flask reached room temperature. AuNPs and conjugates were characterized by dynamic light scattering (DLS) using a zeta potential analysis system (Zetasizer Nano Z, Malvern Instrumentd, Worcestershire, UK), field emission scanning electron microscope (Carl Zeiss) and UV–vis

Performance of colloidal CdS sensitized solar cells with ZnO nanorods/nanoparticles

• Anurag Roy,
• Partha Pratim Das,
• Mukta Tathavadekar,
• Sumita Das and
• Parukuttyamma Sujatha Devi

Beilstein J. Nanotechnol. 2017, 8, 210–221, doi:10.3762/bjnano.8.23

• (150 W) as an excitation source with a bandpass of 5 nm at room temperature. The fluorescence quantum yield of the colloidal CdS solution was measured on the steady state fluorometer using an additional integrating sphere [32]. Zeta potential measurements were carried out on a Horiba Nanoparticle

• temperature. This is an indication of the ratio of the number of fluorescence quanta to the number of absorbed quanta which is directly proportional to the fluorescence lifetime. Zeta potential (ζ) measurements were also carried out to verify the stability of the CdS NPs in ethanol. A zeta potential value of

• . Photovoltaic parameters of colloidal CdS-sensitized ZnO solar cells. Reported performance of CdS-sensitized ZnO-based solar cells. Supporting Information Supporting Information File 26: Additional Experimental Information. Quantitative EDAX spectrum and zeta potential measurement of synthesized colloidal CdS

Streptavidin-coated gold nanoparticles: critical role of oligonucleotides on stability and fractal aggregation

• Roberta D'Agata,
• Pasquale Palladino and
• Giuseppe Spoto

Beilstein J. Nanotechnol. 2017, 8, 1–11, doi:10.3762/bjnano.8.1

• spectroscopic, dynamic light scattering (DLS), zeta-potential (ζ), transmission electron microscopy (TEM) and SPR investigations of ODN-functionalized SA-mediated AuNPs are here presented with the aim to provide fundamental information useful to improve performances of biosensing assays using SA-mediated AuNPs

• spectra shown in Figure 4A (left axis) and by SPR data shown in Figure 6C (right axis), respectively. Extinction spectra (400–800 nm) of AuNP-SA in the presence of free biotin (1.28 mM) titrated with unbiotinylated DNA (solutions: 100 nM, 200 nM and 400 nM, respectively). Data from TEM, DLS and zeta

• potential characterization of nanoparticles (mean ± SD; n = 6 samples × 3 replicate). 0.1 nM nanoparticle dispersion in H2O. Acknowledgements We acknowledge support from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 633937, project ULTRAPLACAD.

Facile fabrication of luminescent organic dots by thermolysis of citric acid in urea melt, and their use for cell staining and polyelectrolyte microcapsule labelling

• Nadezhda M. Zholobak,
• Anton L. Popov,
• Alexander B. Shcherbakov,
• Nelly R. Popova,
• Mykhailo M. Guzyk,
• Valeriy P. Antonovich,
• Alla V. Yegorova,
• Yuliya V. Scrypynets,
• Inna I. Leonenko,
• Alexander Ye. Baranchikov and
• Vladimir K. Ivanov

Beilstein J. Nanotechnol. 2016, 7, 1905–1917, doi:10.3762/bjnano.7.182

• polydispersity index, (in the 100 μg/mL colloidal solution of O-dots, the hydrodynamic diameter was about 300 ± 200 nm), and negative zeta-potential (in the range of pH 5.0…9.0, ζ = −31…−35 mV, see Supporting Information File 1, Figure S16). Such behaviour resembles the properties of surfactants that are prone

Chitosan-based nanoparticles for improved anticancer efficacy and bioavailability of mifepristone

• Huijuan Zhang,
• Fuqiang Wu,
• Yazhen Li,
• Xiping Yang,
• Jiamei Huang,
• Tingting Lv,
• Yingying Zhang,
• Jianzhong Chen,
• Haijun Chen,
• Yu Gao,
• Guannan Liu and
• Lee Jia

Beilstein J. Nanotechnol. 2016, 7, 1861–1870, doi:10.3762/bjnano.7.178

• (Miniflex II, Rigaku, Japan). The X-ray source was Cu Kα radiation (30 kV, 15 mA). AFM images were obtained on a Multimode 8 AFM series (Bruker, USA) in tapping/AC mode. The mean particle size and zeta potential of the MCNs were determined by dynamic light scattering using a Nanotrac® Wave Particle Size and

• Zeta Potential Analyzer (Microtrac Inc, Montgomeryville, PA). Encapsulation efficiency (EE) and drug loading (DL) capacity The EE and the DL of MIF in the MCNs was analyzed by high performance liquid chromatography (HPLC). Briefly, an accurately weighed quantity of the MCN powder was suspended in a

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

• ), zeta potential (ζ-potential) measurements and scanning tunneling microscopy (STM). Further, to demonstrate the environmental application of our AgNPs, we also applied them for heavy metal sensing by detecting visible color modification due to SPR spectral changes. We found that these negatively charged

Antitumor magnetic hyperthermia induced by RGD-functionalized Fe₃O₄ nanoparticles, in an experimental model of colorectal liver metastases

• Oihane K. Arriortua,
• Eneko Garaio,
• Borja Herrero de la Parte,
• Maite Insausti,
• Luis Lezama,
• Fernando Plazaola,
• Jose Angel García,
• Jesús M. Aizpurua,
• Maialen Sagartzazu,
• Mireia Irazola,
• Nestor Etxebarria,
• Ignacio García-Alonso,
• Alberto Saiz-López and
• José Javier Echevarria-Uraga

Beilstein J. Nanotechnol. 2016, 7, 1532–1542, doi:10.3762/bjnano.7.147

• hydrodynamic size for Fe3O4@PMAO_RGD (in a 1:10 PBS/H2O solution) nanoparticles increased until the particles reached a diameter of 111 nm. The zeta potential value at 24 h confirms the high stability of the aqueous solutions of Fe3O4@PMAO (−41 mV), but the stability decreases until −15 mV when RGD is adhered