Tailoring the stability/aggregation of one-dimensional TiO₂(B)/titanate nanowires using surfactants

• Atiđa Selmani,
• Johannes Lützenkirchen,
• Kristina Kučanda,
• Dario Dabić,
• Engelbert Redel,
• Ida Delač Marion,
• Damir Kralj,
• Darija Domazet Jurašin and
• Maja Dutour Sikirić

Beilstein J. Nanotechnol. 2019, 10, 1024–1037, doi:10.3762/bjnano.10.103

• point, pHiep of the TNWs determined from the zeta potential measurements was found to be pH 3.2, as shown in Figure 2. This means that in the investigated pH region (pH > 3.2) bare TNWs are negatively charged. Stability of TNWs and TNW/surfactant dispersions The stability of the materials is of utmost

• repulsive double layer interaction potential (overlapping EDL) and the attractive van der Walls force [53][54]. The average hydrodynamic diameter can be reduced as the zeta potential increases, due to enhanced repulsive electrostatic force and particle stabilization. Effect of TNW concentration on the

• stability of TNW dispersions In this study the stability was followed in dispersions at three different TNW concentrations (γ/g dm−3 = 1 × 10−2 (CS1), 5 × 10−2 (CS2), 1 × 10−1 (CS3)) by monitoring changes in size (dh) and zeta potential (ζ) over 24 h as represented in Table 1 and Figure S8a–d, Supporting

Serum type and concentration both affect the protein-corona composition of PLGA nanoparticles

• Katrin Partikel,
• Robin Korte,
• Dennis Mulac,
• Hans-Ulrich Humpf and
• Klaus Langer

Beilstein J. Nanotechnol. 2019, 10, 1002–1015, doi:10.3762/bjnano.10.101

• assay, zeta potential measurements, and liquid chromatography–mass spectrometry/mass spectrometry (LC–MS/MS). Additionally, the time-dependent cell interaction of PLGA NPs in the absence or presence of a preformed protein corona was assessed by in vitro incubation experiments with the human liver cancer

• complexes from excess serum proteins we used sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE), zeta potential measurements, and liquid chromatography–mass spectrometry/mass spectrometry (LC–MS/MS) to study the composition of adsorbed proteins in detail. A quantitative analysis of corona

• easily trackable in cell culture experiments. Prior to NP incubation with increasing amounts of serum (FBS, human serum) and protein corona analysis the NPs were characterized accurately by PCS and zeta potential measurements. The obtained NPs showed a diameter of approximately 200 nm and a monodisperse

Effects of gold and PCL- or PLLA-coated silica nanoparticles on brain endothelial cells and the blood–brain barrier

• Aniela Bittner,
• Angélique D. Ducray,
• Hans Rudolf Widmer,
• Michael H. Stoffel and
• Meike Mevissen

Beilstein J. Nanotechnol. 2019, 10, 941–954, doi:10.3762/bjnano.10.95

• enter the brain and cause or worsen diseases of the central nervous system [16] that NPs might contribute to [17]. Coated or uncoated mesoporous Si-NPs of different size and zeta potential did not elicit considerable cytotoxicity in MDCK II kidney epithelial cells or RBE4 rat brain ECs but were taken up

• different shape, size (50 to 240 nm) and zeta potential (negative to neutral) did not elicit cytotoxicity in MDCK II kidney epithelial cells and RBE4 ECs at concentrations of up to [50 µg/mL] [18]. As the highest concentration for polymer-coated Si-NPs used in our study was half ([24.9 µg/mL]), the

• of a silica-core doped with rhodamine to enable visualization via fluorescence microscopy, followed by a layer of PCL/ICG and a surface coating with either PCL or PLLA. Characterization of these particle types showed a size of 90 nm for PCL-NPs and 95 nm for PLLA-NPs. The zeta potential was −25.4 mV

Tungsten disulfide-based nanocomposites for photothermal therapy

• Tzuriel Levin,
• Hagit Sade,
• Rina Ben-Shabbat Binyamini,
• Maayan Pour,
• Iftach Nachman and
• Jean-Paul Lellouche

Beilstein J. Nanotechnol. 2019, 10, 811–822, doi:10.3762/bjnano.10.81

• sample on a square piece of a clean silicon wafer and drying overnight at ambient temperature. Zeta potential measurements were performed using a Zetasizer Nano-ZS device (Malvern Instruments Ltd., Worcestershire, UK). Samples for zeta potential measurements were dispersed in water (ca. 0.5 mg/mL

• in TEM, and bright in SEM. A possible reason for this is that CAN-mag composite has a strong positive surface charge (see zeta potential results below in Figure 7), causing electrostatic repulsion forces that prevent a denser coverage. Another point that the electron microscope images show (see

• , namely increased cancerous-cell death and better targeting. Figure 7 shows zeta potential averages and distribution curves for WS2-NTs, CAN-mag, and their composites. The values for WS2-NT and CAN-mag are consistent with previous works [52][65][66]. For each composite, the zeta values reflect the

Polydopamine-coated Au nanorods for targeted fluorescent cell imaging and photothermal therapy

• Boris N. Khlebtsov,
• Andrey M. Burov,
• Timofey E. Pylaev and
• Nikolai G. Khlebtsov

Beilstein J. Nanotechnol. 2019, 10, 794–803, doi:10.3762/bjnano.10.79

• applications, the stability of nanocomposites under ambient conditions is a key factor. Here, we measured zeta potential and the particle-size distribution for all stages of nanocomposite synthesis. The measurements were made in citric buffer (pH 4.4), in water (pH 6.2), and Tris buffer (pH 8.5) (Figure 1E

• ). The CTAB-coated AuNRs were positively charged (zeta potential of about +45 mV) independently of the pH value. The replacement of CTAB with PEG at the first synthetic stage resulted in an almost neutral particle charge (zeta potential varied from −2 to −4 mV). PDA-coated particles have a strong

• negative zeta potential of about −40 mV at neutral and alkaline pH values, whereas resuspension in acidic buffer leads to a recharging of particles, up to +35 mV. This process can be accompanied by particle aggregation when their charge is close to zero (see Figure S2 in Supporting Information File 1

Characterization and influence of hydroxyapatite nanopowders on living cells

• Przemyslaw Oberbek,
• Tomasz Bolek,
• Adrian Chlanda,
• Seishiro Hirano,
• Sylwia Kusnieruk,
• Julia Rogowska-Tylman,
• Ganna Nechyporenko,
• Viktor Zinchenko,
• Wojciech Swieszkowski and
• Tomasz Puzyn

Beilstein J. Nanotechnol. 2018, 9, 3079–3094, doi:10.3762/bjnano.9.286

• , specific surface area, crystallinity, phase purity, stoichiometry, zeta potential and pH value were chosen for correlating the parameters with biological activity. Density measurements Density (ρ) measurements were performed using a helium pycnometer (AccuPyc II, model 1340; Micromeritics, Australia) using

• The average size of HAp nanoobjects in water (L), pH value and zeta potential (ζ) of particles were determined by using dynamic light scattering (DLS, Malvern Instruments Zetasizer Ltd, Spectris). Samples were prepared in 0.02% water solutions with addition of 0.1% Pluronic (used in cell assays, Sigma

• setting of an arbitrary phase-contrast base value for one sample image size. Physicochemical evaluation of nanoparticles Interactions between particles in suspension depend strongly on their zeta potential. Particles having zeta potential values below ±10 mV are considered neutral, with a strong tendency

Colloidal chemistry with patchy silica nanoparticles

• Pierre-Etienne Rouet,
• Cyril Chomette,
• Laurent Adumeau,
• Etienne Duguet and
• Serge Ravaine

Beilstein J. Nanotechnol. 2018, 9, 2989–2998, doi:10.3762/bjnano.9.278

• carboxylic acid groups. The grafting efficiency was evidenced by zeta potential measurements and diffuse reflectance infrared Fourier-transform (DRIFT) spectroscopy. Figure 2b shows that after treatment of the silica surface by APTES, the so-aminated nanoparticles display a quite high zeta potential value of

• about 23 mV at pH 7.0. The isoelectric point (IEP) at pH 8.4 is close to the pKa value of the primary amine groups attesting to their efficient grafting and correct orientation on the silica surface. The carboxylated particles possess a zeta potential of about −43 mV at pH 7.0 and an isoelectric point

• potential of the multipods before and after the chloromethylation/amination of the PS chains (Figure 2e). The comparison of the zeta potential curves shows that the modification stages of the PS residues induce a shift of the IEP to pH 5.3 attesting to the efficient grafting of amine groups. Assembly of

The nanoscaled metal-organic framework ICR-2 as a carrier of porphyrins for photodynamic therapy

• Jan Hynek,
• Sebastian Jurík,
• Martina Koncošová,
• Jaroslav Zelenka,
• Ivana Křížová,
• Tomáš Ruml,
• Kaplan Kirakci,
• Ivo Jakubec,
• František Kovanda,
• Kamil Lang and
• Jan Demel

Beilstein J. Nanotechnol. 2018, 9, 2960–2967, doi:10.3762/bjnano.9.275

• dynamic light scattering (DLS, Figure S3A, Supporting Information File 1). In water, nanoICR-2 forms aggregates with a mean value of the size distribution of 87 ± 31 nm (by number, Z-average = 136 nm, PDI = 0.12). The zeta potential of nanoICR-2 in water is slightly positive with an average of 5 ± 5 mV

• (Figure S3, Supporting Information File 1). These values are somewhat bigger than the size of the parent nanoICR-2 aggregates in water (87 ± 31 nm). Importantly, the zeta potential of the nanoICR-2/porphyrin aggregates switched to negative values: −20 ± 4 mV, −25 ± 5 mV, and −28 ± 5 mV for TPPPi(Me

Hybrid Au@alendronate nanoparticles as dual chemo-photothermal agent for combined cancer treatment

• Anouchka Plan Sangnier,
• Romain Aufaure,
• Laurence Motte,
• Claire Wilhelm,
• Erwann Guenin and
• Yoann Lalatonne

Beilstein J. Nanotechnol. 2018, 9, 2947–2952, doi:10.3762/bjnano.9.273

• negative zeta potential, equal to −37.5 ± 9.1 mV confirms the presence of alendronate on the surface providing negative charges, which allow colloid stabilization despite the presence of ammonium cations. Au@alendronate NPs as NIR photothermal nano-heater Since gold NPs bring their own therapeutic asset

• ) Hydrodynamic diameter distribution (in volume, left) and zeta potential (right) of Au@alendronate NPs. (a) Temperature increase and corresponding typical IR image and (b) SAR (W/g) as a function of the gold concentration under laser irradiation (1.7 W/cm2, 680 nm). Metabolic activity of PC3 cells incubated (a

Comparative biological effects of spherical noble metal nanoparticles (Rh, Pd, Ag, Pt, Au) with 4–8 nm diameter

• Alexander Rostek,
• Marina Breisch,
• Kevin Pappert,
• Kateryna Loza,
• Marc Heggen,
• Manfred Köller,
• Christina Sengstock and
• Matthias Epple

Beilstein J. Nanotechnol. 2018, 9, 2763–2774, doi:10.3762/bjnano.9.258

• to each run. A sample volume of 100 μL was used. Dynamic light scattering (DLS) for particle size analysis and zeta potential determination was carried out on a Malvern Zetasizer Nano ZS ZEN 3600 instrument (25 °C, laser wavelength 633 nm). The scattering was monitored at a fixed angle of 173° in

• ), analytical disc centrifugation (differential centrifugal sedimentation, DCS), ultraviolet (UV) spectroscopy, and high-resolution transmission electron microscopy (HRTEM). All characterization data are summarized in Table 2. All nanoparticles have a neutral or negative zeta potential. This is probably due to

Non-agglomerated silicon–organic nanoparticles and their nanocomplexes with oligonucleotides: synthesis and properties

• Asya S. Levina,
• Marina N. Repkova,
• Nadezhda V. Shikina,
• Zinfer R. Ismagilov,
• Svetlana A. Yashnik,
• Dmitrii V. Semenov,
• Yulia I. Savinovskaya,
• Natalia A. Mazurkova,
• Inna A. Pyshnaya and
• Valentina F. Zarytova

Beilstein J. Nanotechnol. 2018, 9, 2516–2525, doi:10.3762/bjnano.9.234

• groups in oligonucleotides. The Si–NH2 nanoparticles and Si–NH2·ODN nanocomplexes were characterized by transmission electron microscopy, atomic force microscopy and IR and electron spectroscopy. The size and zeta potential values of the prepared nanoparticles and nanocomplexes were evaluated

• agglomeration of the particles). The zeta potential of the studied samples was evaluated by phase analysis light scattering. The value of zeta potential of Si–NH2 is positive due to positively charged amino groups in neutral medium. When the nanoparticles were bound to an oligonucleotide, the zeta potential

• . The spectrum was recorded with absorption compensation relative to water in the range 11000–54000 cm−1 in a quartz cuvette with an optical path length of 1 mm (Figure 2b). The size and zeta potential values of Si–NH2 and Si–NH2·ODN were measured at 5–50 mM concentration (for Si) in physiological

Enhanced antineoplastic/therapeutic efficacy using 5-fluorouracil-loaded calcium phosphate nanoparticles

• Shanid Mohiyuddin,
• Saba Naqvi and
• Gopinath Packirisamy

Beilstein J. Nanotechnol. 2018, 9, 2499–2515, doi:10.3762/bjnano.9.233

• TEM and SEM analysis. Zeta potential analysis The magnitude of the surface charge of the synthesized CaP@5-FU NPs was characterized by zeta potential analysis. The increased electrostatic repulsion between particles corresponding to a higher magnitude of the zeta potential results in reduced

• agglomeration and enhanced colloidal stability [29]. Since the particle stability mainly depends on the electrical charge of the surface, properties such as cellular uptake, rate of drug release, and blood retention time are directly correlated with the zeta potential value. Furthermore, the zeta potential

• value of calcium phosphate nanoparticles was found to have a direct association with Ca/P molar ratio [30]. The molar ratio of the formed nanoparticles in the current study was 3.88. The synthesized CaP@5-FU NPs were found to have a zeta potential of −25.5 mV (Figure 2B). This confirms the nanoparticle

Nanocellulose: Recent advances and its prospects in environmental remediation

• Katrina Pui Yee Shak,
• Yean Ling Pang and
• Shee Keat Mah

Beilstein J. Nanotechnol. 2018, 9, 2479–2498, doi:10.3762/bjnano.9.232

Droplet-based synthesis of homogeneous magnetic iron oxide nanoparticles

• Christian D. Ahrberg,
• Ji Wook Choi and
• Bong Geun Chung

Beilstein J. Nanotechnol. 2018, 9, 2413–2420, doi:10.3762/bjnano.9.226

• potential of 20.2 ± 0.25 mV, and particles synthesized in droplets had a zeta potential of 16.9 ± 0.5 mV. The two measured potentials are in the same range, indicating a relative colloid stability of the particle solutions [33]. To test the advantages of droplet synthesis over batch synthesis, particle size

• concentration is increased by more than one order of magnitude in droplet reactions, the fast precipitation of large amounts of nanoparticles could lead to the buildup of nanoparticle deposits on the fused silica capillaries in some cases and to a blocking of the capillaries. The batch particles showed a zeta

The role of adatoms in chloride-activated colloidal silver nanoparticles for surface-enhanced Raman scattering enhancement

• Nicolae Leopold,
• Andrei Stefancu,
• Krisztian Herman,
• István Sz. Tódor,
• Stefania D. Iancu,
• Vlad Moisoiu and
• Loredana F. Leopold

Beilstein J. Nanotechnol. 2018, 9, 2236–2247, doi:10.3762/bjnano.9.208

• with the distance from the metal surface. Chloride ions, when used at concentrations higher than 0.1 M, induce the aggregation of the metal colloids. The addition of Cl− ions to the colloidal solution reduces the absolute zeta potential value of the nanoparticles, leading to a decrease in the stability

Nanoconjugates of a calixresorcinarene derivative with methoxy poly(ethylene glycol) fragments for drug encapsulation

• Alina M. Ermakova,
• Julia E. Morozova,
• Yana V. Shalaeva,
• Victor V. Syakaev,
• Aidar T. Gubaidullin,
• Alexandra D. Voloshina,
• Vladimir V. Zobov,
• Irek R. Nizameev,
• Olga B. Bazanova,
• Igor S. Antipin and
• Alexander I. Konovalov

Beilstein J. Nanotechnol. 2018, 9, 2057–2070, doi:10.3762/bjnano.9.195

• ] software packages. DLS, SLS, and zeta-potential measurements were carried out by employing a Zetasizer nano ZS with Dispersion Technology Software 5.00. The measurements were carried out at 25 °C in polystyrene cells, for temperature-dependent DLS measurements (25–65 °C) and SLS measurement, a glass

• cuvette PCS8501 (Malvern) was utilized. The SLS measurements were carried out in ethanol solution. Zeta-potential measurements were carried out in folded capillary cells DTS1061 (Malvern). Zeta-potential values were calculated from electrophoretic mobilities by using the Hückel approximation for solutions

Controllable one-pot synthesis of uniform colloidal TiO₂ particles in a mixed solvent solution for photocatalysis

• Jong Tae Moon,
• Seung Ki Lee and
• Ji Bong Joo

Beilstein J. Nanotechnol. 2018, 9, 1715–1727, doi:10.3762/bjnano.9.163

• carbon remained in the particle. However, TiO2-500 and TiO2-800 showed a negligible weight loss, indicating no obvious carbon species in the particle (Supporting Information File 1, Figure S3b). In addition, we measured the zeta potential of the calcined TiO2 samples for estimating the surface charge

• . Although zeta potential values of TiO2 samples do not exactly represent quantitative analysis of surface functional groups, it is a useful method to estimate the surface charge which is highly related with the surface OH group. The results show that the zeta potential values are estimated to be

• approximately −40, −23.8 and −24.9 mV nm for TiO2-350, TiO2-500, and TiO2-800, respectively. It means that the TiO2 sample calcined at low temperature (350 °C) should have a relatively large amount of surface OH groups. Once the calcination temperature is higher than a certain point (e.g., 500 °C), the zeta

Surface characterization of nanoparticles using near-field light scattering

• Eunsoo Yoo,
• Yizhong Liu,
• Chukwuazam A. Nwasike,
• Sebastian R. Freeman,
• Brian C. DiPaolo,
• Bernardo Cordovez and
• Amber L. Doiron

Beilstein J. Nanotechnol. 2018, 9, 1228–1238, doi:10.3762/bjnano.9.114

• )-coated superparamagnetic iron oxide nanoparticles (PEG-SPIOs) with the synthetic pseudotannin polygallol via interpolymer complexation (IPC). Changes in particle size and zeta potential were indirectly assessed via differences between PEG-SPIOs and IPC-SPIOs in particle velocity and scattering intensity

• using near-field light scattering. The local scattering intensity is correlated with the distance between the particle and waveguide, which is affected by the size of the particle (coating thickness) as well as the interactions between the particle and waveguide (related to the zeta potential of the

• the attraction between the nanoparticle and waveguide. Researchers attributed the increased diffusion of PEGylated particles towards the waveguide to the slight reduction in particle surface charge (zeta potential) after PEGylation [24]. This study provided evidence that the nanophotonic force

Green synthesis of fluorescent carbon dots from spices for in vitro imaging and tumour cell growth inhibition

• Nagamalai Vasimalai,
• Vânia Vilas-Boas,
• Juan Gallo,
• María de Fátima Cerqueira,
• Mario Menéndez-Miranda,
• José Manuel Costa-Fernández,
• Lorena Diéguez,
• Begoña Espiña and
• María Teresa Fernández-Argüelles

Beilstein J. Nanotechnol. 2018, 9, 530–544, doi:10.3762/bjnano.9.51

• (inset of Figure 3), which confirms that the obtained C-dots are of crystalline graphitic nature [29][30][31]. Hydrodynamic radii measured by DLS gave rise to values of 11.0, 10.3, 15.0 and 11.2 nm (Figure 4), and zeta potential values of −16.0, −32.9, −16.3 and −24.2 mV for cinnamon, red chilli

• observed between the absolute value of the zeta potential and the cellular uptake observed in both LN-229 and HK-2 cells. XRD patterns of the four synthesized C-dots have been also studied, and the obtained results are given in Figure 5. The cinnamon, red chilli, turmeric and black pepper C-dots

• TEM of 3.37, 3.14, 4.32 and 3.55 nm, respectively. Additionally, the high values of negative zeta potential that all the spice-based C-dots presented ensure a great colloidal stability in biological media. The four different spice-based C-dots have been systematically evaluated to study the in vitro

Photocatalytic and adsorption properties of TiO₂-pillared montmorillonite obtained by hydrothermally activated intercalation of titanium polyhydroxo complexes

• Mikhail F. Butman,
• Nikolay L. Ovchinnikov,
• Nikita S. Karasev,
• Nataliya E. Kochkina,
• Alexander V. Agafonov and
• Alexandr V. Vinogradov

Beilstein J. Nanotechnol. 2018, 9, 364–378, doi:10.3762/bjnano.9.36

• interaction forces between the particles and provides information on the charge state of the surface of particles in the suspension. It is worth noting that all the samples possess negative values of the zeta potential in water. As is evident from Table 3, the zeta potential values for TiO2-PMMx ranged from

• −26.4 to −31.5 mV. The TiO2-PMMHx samples show a decrease in the magnitude of the zeta potential. This result is probably related to the formation of larger particles of TiO2 on the external surface of MM due to flocculation at high titanium content, which leads to a reduction in their electrophoretic

• zeta potential for the samples tested in this work. Elemental analysis of the MM, TiO2-PMM500, and TiO2-PMMН500 samples. Textural characteristics of TiO2-pillared MM samples. Parameters of methyl orange (MO) and rhodamine B (RhB) dye adsorption kinetics for the obtained TiO2-pillared MM samples

Nanoparticle delivery to metastatic breast cancer cells by nanoengineered mesenchymal stem cells

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

Beilstein J. Nanotechnol. 2018, 9, 321–332, doi:10.3762/bjnano.9.32

• shell coated with an amphiphilic polymer and functionalised with carboxylate. The QDs have an emission maxima of 655 nm. Xu et al. reported that the hydrodynamic diameter of the nanoparticles is 14.55 ± 4.157 nm and the zeta potential is −35.1 mV [51]. The stock solution was prepared at a concentration

The nanofluidic confinement apparatus: studying confinement-dependent nanoparticle behavior and diffusion

• Stefan Fringes,
• Felix Holzner and
• Armin W. Knoll

Beilstein J. Nanotechnol. 2018, 9, 301–310, doi:10.3762/bjnano.9.30

• dispersion was used within a few hours. A pH of 6.8 ± 0.2, a zeta potential of ζ = −58 mV, a specific conductivity of Λ = 11.5 μS cm−1, and hydrodynamic diameter of 2a = 62.1 nm were measured for a 1:150 diluted dispersion using a Malvern Zetasizer. We observed a linear dependency between the conductivity

A comparative study of the nanoscale and macroscale tribological attributes of alumina and stainless steel surfaces immersed in aqueous suspensions of positively or negatively charged nanodiamonds

• Colin K. Curtis,
• Antonin Marek,
• Alex I. Smirnov and
• Jacqueline Krim

Beilstein J. Nanotechnol. 2017, 8, 2045–2059, doi:10.3762/bjnano.8.205

• samples were carboxylated [2][28], (part# ND5nmNH20) and as manufactured have an average particle size of 5 nm and a zeta potential of −50 mV [29]. The +ND samples were hydroxylated in the course of a reduction reaction [28], (part# ND5nmPH20) and, as manufactured, have an average particle size of 5 nm

• and a zeta potential of +45 mV. The suspensions were employed as received from the manufacturer in the form of 1 wt % slurries in DI water, and stored without exposure to light. The suspensions were diluted tenfold by volume in advance of experiments using DI water to yield 0.1 wt % suspensions

• shear. Therefore a custom design of nanolubrication systems by a proper chemical passivation of ND surfaces appears as a promising approach. Hydroxylated NDs bearing a positive zeta potential in aquelus dispersion, produced no significant response in the frequency or resistance behavior of the QCM

Carbon nano-onions as fluorescent on/off modulated nanoprobes for diagnostics

• Stefania Lettieri,
• Marta d’Amora,
• Adalberto Camisasca,
• Alberto Diaspro and
• Silvia Giordani

Beilstein J. Nanotechnol. 2017, 8, 1878–1888, doi:10.3762/bjnano.8.188

• environment. The oxi-CNOs were found to have an effective hydrodynamic diameter of 274 ± 16 nm, while the fluo-CNOs have an average diameter of 357 ± 32 nm. The zeta potential changed from −45 ± 5 mV for the oxi-CNOs to −35.9 ± 1 mV for the fluo-CNOs, confirming the functionalization of the oxi-CNOs with the

• concentrations of 20, 10 and 5 μg mL−1. Dynamic light scattering and zeta potential measurements DLS measurements were performed on the Malvern Nano-ZS instrument operating in backscattering (173°) mode and analyzed with the Zetasizer software, with automatic selection of the optimal detector position and number

• −1. The CNO samples were sonicated for an additional 20 min and the particle size was measured. Zeta potential measurements were performed on the same apparatus using the disposable zeta potential cuvettes. NMR spectroscopy NMR spectroscopy was performed on a Bruker Avance III 400 MHz system (400.13

Self-assembly of chiral fluorescent nanoparticles based on water-soluble L-tryptophan derivatives of p-tert-butylthiacalix[4]arene

• Pavel L. Padnya,
• Irina A. Khripunova,
• Olga A. Mostovaya,
• Timur A. Mukhametzyanov,
• Vladimir G. Evtugyn,
• Vyacheslav V. Vorobev,
• Yuri N. Osin and
• Ivan I. Stoikov

Beilstein J. Nanotechnol. 2017, 8, 1825–1835, doi:10.3762/bjnano.8.184

• of the compounds 8–11. The zeta potential is another measure of the stability of colloidal systems. The zeta potential characterizes the degree and nature of the interaction between the particles of the disperse system: the larger the electrokinetic potential, the more stable the colloidal system. A

• low zeta potential determines the tendency of the particles of a colloidal solution to coagulate and flocculate. It has been experimentally established [42] that the critical value of the zeta potential corresponding to the stability threshold of a colloidal system is 30 mV. The zeta potential of the

• thiacalix[4]arene solutions 8–11 was determined at a concentration of 1 × 10−4 М in water (Table 2, Supporting Information File 1, Figure S21–S24). Large zeta potential values (more than 30 mV) also confirm the high stability of the aggregates of these compounds. For the associates of the compound 11, which