Atomic layer deposited films of Al₂O₃ on fluorine-doped tin oxide electrodes: stability and barrier properties

• Hana Krýsová,
• Michael Neumann-Spallart,
• Hana Tarábková,
• Pavel Janda,
• Ladislav Kavan and
• Josef Krýsa

Beilstein J. Nanotechnol. 2021, 12, 24–34, doi:10.3762/bjnano.12.2

• redox couples (ferricyanide/ferrocyanide) in aqueous media. However, these films were rapidly dissolved in 1 M NaOH (≈100 nm/h). The dissolution was slower in 1 M H2SO4 (1 nm/h) but after 24 h the blocking behaviour was entirely lost. The optimal stability was reached at pH 7.2 where no changes were

• semiconducting electrodes, such as ZnO. Aluminium oxide is another promising candidate for this task. It is amphoteric but insoluble in aqueous media at a neutral pH value [8][9]. ALD oxide layers, including Al2O3, were used as barrier coatings on copper to protect against corrosion in 0.1 M NaCl [10]. As

• -deposited ALD Al2O3 films are typically amorphous with a poor resistance to chemical attack [11][12][13]. These films do not withstand, for example, exposition to environmental media, such as 5% NaCl and sea water, to diluted HCl and H2SO4 (pH 4) [11], to acidic (1 M H2SO4) or alkaline (1 M NaOH) solutions

Bio-imaging with the helium-ion microscope: A review

• Matthias Schmidt,
• James M. Byrne and
• Ilari J. Maasilta

Beilstein J. Nanotechnol. 2021, 12, 1–23, doi:10.3762/bjnano.12.1

• et al. [19] and a study on the pH-responsive encapsulation of bacteriophages for phage therapy by Vinner et al. [20] are first examples. Since the early days of HIM, attempts have been made to add nanoscale analytics to the HIM. Already in 2007, Notte et al. stated in their article “An Introduction

Nanocasting synthesis of BiFeO₃ nanoparticles with enhanced visible-light photocatalytic activity

• Thomas Cadenbach,
• Maria J. Benitez,
• A. Lucia Morales,
• Cesar Costa Vera,
• Luis Lascano,
• Francisco Quiroz,
• Alexis Debut and
• Karla Vizuete

Beilstein J. Nanotechnol. 2020, 11, 1822–1833, doi:10.3762/bjnano.11.164

• in 30 mL of HNO3-acidified water at pH 3. After stirring the solution for 4 h at room temperature the solvent was removed by evaporation using a membrane pump vacuum on a rotary evaporator at 75 °C. Then, the sample was dried for 16 h in a ventilated oven at 75 °C until a dry powder was obtained

• no crystalline impurity is detected. The degradation efficiency of the 5.5 nm BiFeO3 particles in the presence of RhB at different pH values ranging from pH 2 to pH 9 was also investigated (Figure 11). In general, varying the pH value of the reaction medium changes both structure and charge of the

• dye, as well as the surface-charge properties of the catalyst. For instance, at neutral pH values RhB is characterized by a zwitter ionic state, whereas it forms a cationic species upon protonation of a carboxylic group at pH values below its pKS2 value of 3.22. Under basic reaction conditions BiFeO3

PEG/PEI-functionalized single-walled carbon nanotubes as delivery carriers for doxorubicin: synthesis, characterization, and in vitro evaluation

• Shuoye Yang,
• Zhenwei Wang,
• Yahong Ping,
• Yuying Miao,
• Yongmei Xiao,
• Lingbo Qu,
• Lu Zhang,
• Yuansen Hu and
• Jinshui Wang

Beilstein J. Nanotechnol. 2020, 11, 1728–1741, doi:10.3762/bjnano.11.155

• efficiently, and release the loaded DOX in a pH value-dependent manner. They show effective growth inhibition towards tumor cells through inducing apoptosis. Experimental Chemicals and reagents SWCNTs with high purity were purchased from Chengdu Organic Chemicals Co. Ltd., Chinese Academy of Sciences

• was collected and washed with deionized water to adjust the pH value to 6.8–7.2. These steps were repeated to remove the unacidified SWCNTs. The shortened CNTs were finally obtained by vacuum drying at 50 °C for 24 h. The resulting purified sample was denominated CNTs-COOH (CNTs). The purified CNTs

• suspended in DOX solution (1 mg·mL−1, 10 mL, dissolved in PBS, pH 7.4) and stirred at 37 °C for 24 h. After centrifuging, the precipitate was collected and washed with PBS. Finally, DOX-loaded samples were obtained by centrifugation and vacuum drying. Samples were prepared the day before the experiment and

Cardiomyocyte uptake mechanism of a hydroxyapatite nanoparticle mediated gene delivery system

• Hiroaki Komuro,
• Masahiro Yamazoe,
• Kosuke Nozaki,
• Akiko Nagai and
• Tetsuo Sasano

Beilstein J. Nanotechnol. 2020, 11, 1685–1692, doi:10.3762/bjnano.11.150

• pH-sensitive [7][8][9]. Besides, CaP can be internalized in targeting cells though the endocytic pathway. Later on, CaP is dissolved in the endosome under acidic conditions, which contributes to the DNA release into the cytosol before the endosome–lysosome fusion. Although there are a number of

Electrokinetic characterization of synthetic protein nanoparticles

• Daniel F. Quevedo,
• Cody J. Lentz,
• Adriana Coll de Peña,
• Yazmin Hernandez,
• Nahal Habibi,
• Rikako Miki,
• Joerg Lahann and
• Blanca H. Lapizco-Encinas

Beilstein J. Nanotechnol. 2020, 11, 1556–1567, doi:10.3762/bjnano.11.138

• , naturally involved in biological molecule targeting, and are “smart” materials that can respond to various environmental cues, such as pH value, temperature, or target binding [4]. Protein nanoparticles (PNPs) are useful for the loading of active therapeutic enzymes and show potential results to be used as

• mg·mL−1 in ultrapure H2O + 0.01% Tween 20. Particles were then diluted to 250 mg·mL−1 in the same suspension medium used to fill the device (DI water with added K2HPO4 to reach pH 6.2 and a conductivity of 21.3 µS·cm−1, supplemented with 0.05% Tween 20) and subsequently sonicated to break up particle

Cu₂O nanoparticles for the degradation of methyl parathion

• Juan Rizo,
• David Díaz,
• Benito Reyes-Trejo and
• M. Josefina Arellano-Jiménez

Beilstein J. Nanotechnol. 2020, 11, 1546–1555, doi:10.3762/bjnano.11.137

• pH value because glucose is the reducing agent. Alkaline pH values favor the open-chain form of glucose also known as the aldehyde form, and the aldehyde group makes glucose a reducing sugar. It is essential to point out that different mixtures of H2O and DMSO are used in order to obtain NPs of

• depending on the NP size (Figure 7 and Figure 8). A smaller nanoparticle size leads to a higher concentration of 4-nitrophenolate. 4-NPh is in equilibrium with 4-NPh− (Scheme 1). According to Le Chatelier’s principle, the equilibrium favors the formation of 4-NPh− at basic pH values. This means that the NPs

Wafer-level integration of self-aligned high aspect ratio silicon 3D structures using the MACE method with Au, Pd, Pt, Cu, and Ir

• Mathias Franz,
• Romy Junghans,
• Paul Schmitt,
• Adriana Szeghalmi and
• Stefan E. Schulz

Beilstein J. Nanotechnol. 2020, 11, 1439–1449, doi:10.3762/bjnano.11.128

• metal–insulator–semiconductor or metal–insulator–metal capacitors with a high effective area on a small footprint. The high surface area of a silicon nanowire array can be used to fabricate ion-sensitive field-effect transistors (ISFETs) with a high signal-to-noise ratio. An ISFET is a pH sensing

Transient coating of γ-Fe₂O₃ nanoparticles with glutamate for its delivery to and removal from brain nerve terminals

• Konstantin Paliienko,
• Artem Pastukhov,
• Michal Babič,
• Daniel Horák,
• Olga Vasylchenko and
• Tatiana Borisova

Beilstein J. Nanotechnol. 2020, 11, 1381–1393, doi:10.3762/bjnano.11.122

• of glutamate and aspartate by chemically modified γ-Fe2O3 nanoparticles. The glutamate and aspartate solutions were prepared in HNO3 at pH 3.0 and under nitrogen flux. The chemisorption was investigated in acidic medium by measuring the changes in the conductivity of the solution during addition of

• and the membrane potential of nerve terminals. Six animals were used for blood plasma preparation. Isolation of nerve terminals (synaptosomes) from rat cortex The cortex zone of the rat brain was rapidly removed and homogenized in ice-cold 0.32 M sucrose, 5 mM HEPES-NaOH, pH 7.4 and 0.2 mM EDTA. The

• an oxygenated standard salt solution (NaCl 126 mM, KCl 10 mM, MgCl2 2.0 mM, NaH2PO4 1.0 mM, HEPES 20 mM, pH 7.4; and ᴅ-glucose 10 mM) at 37 °C for 8 min. γ-Fe2O3 nanoparticles were added to the synaptosomal suspension and further incubated for 10 min. The uptake of the neurotransmitter was started by

Impact of fluorination on interface energetics and growth of pentacene on Ag(111)

• Qi Wang,
• Meng-Ting Chen,
• Antoni Franco-Cañellas,
• Bin Shen,
• Thomas Geiger,
• Holger F. Bettinger,
• Frank Schreiber,
• Ingo Salzmann,
• Alexander Gerlach and
• Steffen Duhm

Beilstein J. Nanotechnol. 2020, 11, 1361–1370, doi:10.3762/bjnano.11.120

• the photon energy, which allowed to determine the coherent position (PH) and the coherent fraction (fH) of the adsorbate atoms [66][69]. The former gave the adsorption distance in terms of the lattice spacing of the silver substrate: dH = d0(n + PH) (typical precision < 0.05 Å), with n being an

• ) Reflectivity and photoelectron yield (Yp) as a function of the photon energy (hυ) relative to the Bragg energy (EBragg = 2630 eV) for a (sub)monolayer (<2 Å) F4PEN thin film on Ag(111). For each element, the coherent position (PH) and the coherent fraction (fH) are given. (d) Chemical structure of F4PEN. (e

Ultrasensitive detection of cadmium ions using a microcantilever-based piezoresistive sensor for groundwater

• Dinesh Rotake,
• Anand Darji and
• Nitin Kale

Beilstein J. Nanotechnol. 2020, 11, 1242–1253, doi:10.3762/bjnano.11.108

• -linked for selectivity. We have cross-linked the amine group with ᴅʟ-glyceraldehyde at pH 7 to obtain a free –OH group (a Lewis acid) for capturing Cd(II). The pKa value of 12.6 of ᴅʟ-glyceraldehyde yield a strong copmplex of the –OH group with cadmium [34] after blocking the –NH2 group of cysteamine

• phosphate buffer saline (PBS, pH 7) according to [34] was prepared. The cysteamine SAM was allowed to cross-link with the ᴅʟ-glyceraldehyde solution for at least 2–3 hours by covering the container using silver foil. Stock solutions of 1 mM/10 mL of different salts (AlCl3, MnCl2, CrCl3, HgCl2, PbCl2, CdCl2

• authors have used colorimetric or fluorescence techniques for selective HMI detection but they are highly sensitive to variation of pH values [67]. In a colorimetric sensor, the concentration variation is shown by different shades of color and it is challenging to exactly identify the shades for the

Magnetic-field-assisted synthesis of anisotropic iron oxide particles: Effect of pH

• Andrey V. Shibaev,
• Petr V. Shvets,
• Darya E. Kessel,
• Roman A. Kamyshinsky,
• Anton S. Orekhov,
• Sergey S. Abramchuk,
• Alexei R. Khokhlov and
• Olga E. Philippova

Beilstein J. Nanotechnol. 2020, 11, 1230–1241, doi:10.3762/bjnano.11.107

• properties is the pH during synthesis. This is due to the fact that the OH− ion concentration in the reaction mixture controls the reaction rate and, therefore, the nanocrystal growth mechanism. For instance, Ahn et al. [31] studied the formation of magnetite nanoparticles by performing co-precipitation

• transformation into magnetite. The reaction pathway was strongly dependent on R and also on the rate in which the base was added. At the same time, the effect of pH on the templated directional synthesis of iron oxide as well as the formation of nanorods within this context are yet to be determined. In this work

• , for the first time, the effect of pH on the magnetic-field-assisted synthesis of iron oxide nanoparticles was investigated. The results show that different nanostructures were formed upon varying the initial pH of the reaction mixture: spheres were obtained at a highly alkaline pH whereas rods were

High permittivity, breakdown strength, and energy storage density of polythiophene-encapsulated BaTiO₃ nanoparticles

• Adnanullah Khan,
• Amir Habib and
• Adeel Afzal

Beilstein J. Nanotechnol. 2020, 11, 1190–1197, doi:10.3762/bjnano.11.103

• dioxide (TiO2 Tronox, 99.5%, Tronox Pigments GmbH) are used as Ba and Ti precursors for the hydrothermal synthesis of BTO nanoparticles. Ba(OH)2·8H2O also acts as the mineralizer and prevents the use of NaOH or KOH for controlling the pH value of the reaction mixture [12]. Equimolar amounts of Ba and Ti

Photothermally active nanoparticles as a promising tool for eliminating bacteria and biofilms

• Mykola Borzenkov,
• Piersandro Pallavicini,
• Angelo Taglietti,
• Laura D’Alfonso,
• Maddalena Collini and
• Giuseppe Chirico

Beilstein J. Nanotechnol. 2020, 11, 1134–1146, doi:10.3762/bjnano.11.98

• intensively studied within the broad spectrum of existing nanomaterials [10][11][12][13][14][15]. However, the low stability (even at physiological pH levels) and the potential toxicity of Ag NPs limit their application [7][16]. Moreover, the results regarding the efficiency of Ag NPs in preventing biofilm

• acidic biofilm microenvironment and an enhanced photothermal ablation of methicillin-resistant S. aureus biofilm under NIR light irradiation (laser intensity 0.91 W/cm2), were previously reported [57]. The gold nanoparticles were modified by pH-responsive mixed-charged zwitterionic self-assembled

• monolayers consisting of a weak electrolytic (i.e., pH-sensitive), 11-mercaptoundecanoic acid, a strong electrolytic (i.e., pH-independent), and (10-mercaptodecyl)trimethylammonium bromide. In addition, the resulting photothermal effect did not cause damage to the surrounding healthy tissue. Multibranched

Applications of superparamagnetic iron oxide nanoparticles in drug and therapeutic delivery, and biotechnological advancements

• Maria Suciu,
• Corina M. Ionescu,
• Alexandra Ciorita,
• Septimiu C. Tripon,
• Dragos Nica,
• Hani Al-Salami and
• Lucian Barbu-Tudoran

Beilstein J. Nanotechnol. 2020, 11, 1092–1109, doi:10.3762/bjnano.11.94

• properties of the nanoparticle. The real dimension of a nanoparticle is the one measured in suspension in the colloidal state. It differs depending on suspension medium, pH value, concentration, and ionic strength. The hydrodynamic dimension is much larger than the real dimension of a nanoparticle, as it

• increase in macrophages. The general consideration is that polymer coating offers colloidal stability, but in fact PVA-coated SPIONs are only stable in water at a certain pH value. In cell culture medium they agglomerate. Studies showed that the components of the medium, and not the calf serum added to the

• biological fluids at physiological pH values and which remain stable with low toxicity in vitro [38][46][98][99][100][101][102][103]. Still, Hong and collaborators [104] stress the fact that we should pay more attention to the charge effects of SPIONs because not all types of cytotoxicity can be easily and

Plant growth regulation by seed coating with films of alginate and auxin-intercalated layered double hydroxides

• Vander A. de Castro,
• Valber G. O. Duarte,
• Danúbia A. C. Nobre,
• Geraldo H. Silva,
• Vera R. L. Constantino,
• Frederico G. Pinto,
• Willian R. Macedo and
• Jairo Tronto

Beilstein J. Nanotechnol. 2020, 11, 1082–1091, doi:10.3762/bjnano.11.93

• the new LDH-phosphate fertilizer. Furthermore, the application of LDH-phosphate yielded an increased pH value of the soil, thus contributing to the decrease of the phosphorus adsorption capacity of the soil, making this nutrient more available to the plants. These results confirmed that LDH-phosphate

• NAA into ZnAl-LDH (Zn/Al molar ratio = 3.5) by co-precipitation and performed in vitro release studies. The anion release rate depended on the pH value of the medium. From the beginning of the experiment up to 8 h, the release of 23.2% and 22.0% of NAA in solutions of initially pH 1 and pH 7

• , respectively, followed a first-order kinetic. In neutral pH solution, a release of 75.0% of NAA was verified after 168 h and the inorganic layered structure was kept integral in the first 7 days of the experiment. Li et al. [26] synthesized two MgAl-LDHs (Mg/Al molar ratio = 2.0) intercalated with NAA and IBA

Highly sensitive detection of estradiol by a SERS sensor based on TiO₂ covered with gold nanoparticles

• Andrea Brognara,
• Ili F. Mohamad Ali Nasri,
• Beatrice R. Bricchi,
• Andrea Li Bassi,
• Caroline Gauchotte-Lindsay,
• Matteo Ghidelli and
• Nathalie Lidgi-Guigui

Beilstein J. Nanotechnol. 2020, 11, 1026–1035, doi:10.3762/bjnano.11.87

• , 0.1 M of NaCl and 5 mM of MgCl2, pH 7.5). The samples were left for 2 h in this solution before rinsing with Tris-HCl buffer solution and Milli-Q water. In order to prevent unspecific interactions between E2 and the gold surface, the sample was then left for 2 h in a solution of the blocking agent MCH

Microwave-induced electric discharges on metal particles for the synthesis of inorganic nanomaterials under solvent-free conditions

• Vijay Tripathi,
• Harit Kumar,
• Anubhav Agarwal and
• Leela S. Panchakarla

Beilstein J. Nanotechnol. 2020, 11, 1019–1025, doi:10.3762/bjnano.11.86

• 10 mL of 0.5 M nitric acid and sonicated for 10 min. The resultant powder is washed with water several times until pH 7 and dried it in an oven at 50 °C for 2 h before being used in further microwave experiments. Synthesis of graphitic carbon nitride (g-C3N4) g-C3N4 is synthesized and characterized

Atomic layer deposition for efficient oxygen evolution reaction at Pt/Ir catalyst layers

• Stefanie Schlicht,
• Korcan Percin,
• Stefanie Kriescher,
• André Hofer,
• Claudia Weidlich,
• Matthias Wessling and
• Julien Bachmann

Beilstein J. Nanotechnol. 2020, 11, 952–959, doi:10.3762/bjnano.11.79

• composition and pH value, temperature, or reference electrode), or even the choice of performance parameters (current density at a given overpotential, mass activity based on noble-metal loading, or overpotential for a given current), are usually different. Hence, often direct comparisons between catalysts of

A 3D-polyphenylalanine network inside porous alumina: Synthesis and characterization of an inorganic–organic composite membrane

• Jonathan Stott and
• Jörg J. Schneider

Beilstein J. Nanotechnol. 2020, 11, 938–951, doi:10.3762/bjnano.11.78

• deprotection of the side chain. This enables formation of pH-responsive hydrogels [28]. Stable, thermoresponsive organo-gels consisting of polybenzylglutamate-α-helices were studied by Niehoff et al. [29]. Gelated polybenzylglutamate molecules with molecular weight from approximately 7000 to 100 000 g/mol were

Key for crossing the BBB with nanoparticles: the rational design

• Sonia M. Lombardo,
• Marc Schneider,
• Akif E. Türeli and
• Nazende Günday Türeli

Beilstein J. Nanotechnol. 2020, 11, 866–883, doi:10.3762/bjnano.11.72

• model and showed that CBSA-nanoparticles had an apparent permeability (Pe) seven times higher than that of BSA-nanoparticles. Furthermore, a leaching study of coumarin-6 was performed at pH 4.0 and 7.4 and showed that less than 1% of the dye was released from the nanoparticles after 80 h. Thus, coumarin

Nickel nanoparticles supported on a covalent triazine framework as electrocatalyst for oxygen evolution reaction and oxygen reduction reactions

• Secil Öztürk,
• Yu-Xuan Xiao,
• Dennis Dietrich,
• Beatriz Giesen,
• Juri Barthel,
• Jie Ying,
• Xiao-Yu Yang and
• Christoph Janiak

Beilstein J. Nanotechnol. 2020, 11, 770–781, doi:10.3762/bjnano.11.62

• same group also produced a Cu-modified CTF hybridized with carbon nanoparticles and it showed the highest reported value among Cu-based electrocatalysts with 810 mV onset potential vs RHE for the ORR at neutral pH value [37]. In contrast, up to now there are only few studies that investigated CTFs as

Silver-decorated gel-shell nanobeads: physicochemical characterization and evaluation of antibacterial properties

• Marta Bartel,
• Katarzyna Markowska,
• Marcin Strawski,
• Krystyna Wolska and
• Maciej Mazur

Beilstein J. Nanotechnol. 2020, 11, 620–630, doi:10.3762/bjnano.11.49

• anionic sulfonic groups) should be considerably diminished. To test this hypothesis, zeta potential measurements have been done. The analysis was performed in buffer solutions from pH 3 to pH 10 for the PSSAg beads, but also for PSS particles, PSS beads with incorporated silver ions and silver

• nanoparticles (non-incorporated in the polymer). The data is shown in Figure 6. One can see that for the PSS and the PSS with incorporated Ag+ ions the obtained results are very similar. At high pH values, the zeta potential values are ca. −30 mV, while they gradually increase with increasing pH value. This can

• be explained assuming that in both cases the negative charge of sulfonic groups is neutralized by sodium or silver cations. With decreasing pH values the sulfonate groups are increasingly protonated and the absolute value of the zeta potential decreases. The zeta potential of PSSAg beads exhibits

Soybean-derived blue photoluminescent carbon dots

• Shanshan Wang,
• Wei Sun,
• Dong-sheng Yang and
• Fuqian Yang

Beilstein J. Nanotechnol. 2020, 11, 606–619, doi:10.3762/bjnano.11.48

• varies with pH and temperature [18]. Wang et al. [18] studied the fluorescence of the CDs made from glucose with glutathione in a temperature range of 15 to 90 °C and observed the change of the color from dark blue to light blue and the quenching of the fluorescence at high temperatures. They attributed

Adsorptive removal of bulky dye molecules from water with mesoporous polyaniline-derived carbon

• Hyung Jun An,
• Jong Min Park,
• Nazmul Abedin Khan and
• Sung Hwa Jhung

Beilstein J. Nanotechnol. 2020, 11, 597–605, doi:10.3762/bjnano.11.47

• JGB under a wide range of pH values (from 2 to 12). Results and Discussion Characterization of polyaniline-derived carbon (PDC) The porosity and pore size distribution of the adsorbents were characterized with nitrogen adsorption at 77 K. As shown in Figure 1a, the porosity of the PDC materials was

• bonding [57][58][59], were applied to interpret various adsorption events. In order to understand the plausible mechanism, especially in aqueous phase, adsorption over a wide range of pH conditions is very effective [60] since both the adsorbate and adsorbent can be changed in terms of charge or

• functional group (for example, via protonation or deprotonation) under different conditions of acidity/basicity. In this study, the q6h values were checked over KOH-900 for AR1 and JBG under pH 2–12. As shown in Figure 7, the q6h for AR1 decreased monotonously with increasing pH of the solution; however, the