Electrocatalytic oxygen reduction activity of AgCoCu oxides on reduced graphene oxide in alkaline media

• Iyyappan Madakannu,
• Indrajit Patil,
• Bhalchandra Kakade and
• Kasibhatta Kumara Ramanatha Datta

Beilstein J. Nanotechnol. 2022, 13, 1020–1029, doi:10.3762/bjnano.13.89

• the overall performance of the reaction [3][4]. There is an increasing use of platinum catalysts with diverse morphologies and the combination with noble and non-noble metal-based alloy/multimetallic nanoparticles (NPs) as potential electrocatalysts under extreme pH values [5][6][7][8][9][10][11][12

Solar-light-driven LaFe_xNi_1−xO₃ perovskite oxides for photocatalytic Fenton-like reaction to degrade organic pollutants

• Chao-Wei Huang,
• Shu-Yu Hsu,
• Jun-Han Lin,
• Yun Jhou,
• Wei-Yu Chen,
• Kun-Yi Andrew Lin,
• Yu-Tang Lin and
• Van-Huy Nguyen

Beilstein J. Nanotechnol. 2022, 13, 882–895, doi:10.3762/bjnano.13.79

• ), Chengalpattu district, Kelambakkam, Tamil Nadu, 603103, India 10.3762/bjnano.13.79 Abstract LaFexNi1−xO3 perovskite oxides were prepared by the sol–gel method under various conditions, including different pH values (pH 0 and pH 7) and different calcination temperatures (500–800 °C) as well as different Fe/Ni

• decompose the methylene blue molecules. Accordingly, the synthesis condition of pH 0, calcination temperature at 700 °C, and Fe/Ni ratio = 7/3 could form LaFe0.7Ni0.3O3 perovskite oxides as highly efficient photocatalysts. Moreover, various conditions during the photocatalytic degradation were verified

• , such as pH value, catalyst dosage, and the additional amount of H2O2. LaFe0.7Ni0.3O3 perovskite oxides could operate efficiently under pH 3.5, catalyst dosage of 50 mg/150 mL, and H2O2 concentration of 133 ppm to decompose the MB dye in the 1st order kinetic rate constant of 0.0506 s−1. Keywords

DNA aptamer selection and construction of an aptasensor based on graphene FETs for Zika virus NS1 protein detection

• Nathalie B. F. Almeida,
• Thiago A. S. L. Sousa,
• Viviane C. F. Santos,
• Camila M. S. Lacerda,
• Thais G. Silva,
• Rafaella F. Q. Grenfell,
• Flavio Plentz and
• Antero S. R. Andrade

Beilstein J. Nanotechnol. 2022, 13, 873–881, doi:10.3762/bjnano.13.78

• solution dispersed in 1 mM PBS (phosphate-buffered saline: 0.0001 M phosphate buffer, 0.000027 M potassium chloride, and 0.00137 M sodium chloride), pH 7.4. After incubation, the graphene devices were rinsed with 1 mM PBS, followed by sequential rinsing with deionized water and drying in a nitrogen flow

Self-assembly of C₆₀ on a ZnTPP/Fe(001)–p(1 × 1)O substrate: observation of a quasi-freestanding C₆₀ monolayer

• Guglielmo Albani,
• Michele Capra,
• Alessandro Lodesani,
• Alberto Calloni,
• Gianlorenzo Bussetti,
• Marco Finazzi,
• Franco Ciccacci,
• Alberto Brambilla,
• Lamberto Duò and
• Andrea Picone

Beilstein J. Nanotechnol. 2022, 13, 857–864, doi:10.3762/bjnano.13.76

• ZnTPP spectrum in Figure 3, the UPS peaks related to the main molecule ring and to the phenyl groups are labeled “R” and “Ph” [52][53], respectively, according to theoretical simulations performed on metal tetraphenyl porphyrins and metal porphyrins [54]. When an additional single layer of C60 is added

Gelatin nanoparticles with tunable mechanical properties: effect of crosslinking time and loading

• Agnes-Valencia Weiss,
• Daniel Schorr,
• Julia K. Metz,
• Metin Yildirim,
• Saeed Ahmad Khan and
• Marc Schneider

Beilstein J. Nanotechnol. 2022, 13, 778–787, doi:10.3762/bjnano.13.68

• macromolecules, such as proteins [12] and peptides [13], or in the field of gene delivery [14]. The surface charge of gelatin nanoparticles at physiological pH can be easily influenced by the choice of gelatin type [15]. Crosslinking of gelatin nanoparticles is still inevitable to obtain particles that are

• polydispersity index (PdI) from 0.075 to 0.115, indicating a narrow size distribution. Crosslinking for 15 min did not result in stable particles with uniform colloidal properties. The surface charge of gelatin nanoparticles is clearly pH-dependent. At a pH value of 7.5 ± 0.1, the zeta potential values ranged

• pH (−36.0 ± 1.18 mV). The achieved entrapment efficiency was comparable to the loading determined in a previous study in our lab [12]. Crosslinking degree and Young’s moduli Regarding the mechanical properties of the gelatin nanoparticles, a clear dependency of Young’s moduli on the crosslinking time

Recent advances in nanoarchitectures of monocrystalline coordination polymers through confined assembly

• Lingling Xia,
• Qinyue Wang and
• Ming Hu

Beilstein J. Nanotechnol. 2022, 13, 763–777, doi:10.3762/bjnano.13.67

• coordination polymers as envelopes for the bio-entities. On the basis of the sensitive coordination bonds, the stored bio-entities may be released from solution triggered by pH value or other factors. In 2015, Falcaro et al. demonstrated that monocrystalline ZIF-8 can take up proteins, enzymes, and DNA [104

Hierarchical Bi₂WO₆/TiO₂-nanotube composites derived from natural cellulose for visible-light photocatalytic treatment of pollutants

• Zehao Lin,
• Zhan Yang and
• Jianguo Huang

Beilstein J. Nanotechnol. 2022, 13, 745–762, doi:10.3762/bjnano.13.66

• corresponding Cr(VI) pollutant solution. In addition, the pH values (2, 3, 4, and 5) of the initial Cr(VI) pollutant solution were adjusted using the H2SO4 (0.1 M) aqueous solution. In order to obtain the photocatalytic performances of the samples, the removal percentage of Cr(VI) and degradation percentage of

• hierarchical Bi2WO6/TiO2-NT nanocomposites. It is reported that the pH value of the Cr(VI) pollutant solution has an important influence in the photocatalytic reduction of Cr(VI) [53]. In order to investigate the photocatalytic reduction activities of the samples toward Cr(VI), the 70%−Bi2WO6/TiO2-NT

• nanocomposite was set as the representative photocatalyst for the exploration of optimal pH values of the Cr(VI) pollutant solution under visible-light irradiation. It was demonstrated that the reduction efficiency of Cr(VI) under the alkaline condition was poor because the newly formed Cr(OH)3 precipitates

A nonenzymatic reduced graphene oxide-based nanosensor for parathion

• Sarani Sen,
• Anurag Roy,
• Ambarish Sanyal and
• Parukuttyamma Sujatha Devi

Beilstein J. Nanotechnol. 2022, 13, 730–744, doi:10.3762/bjnano.13.65

• monitoring of PT. For this purpose, the electrochemical reduction of GO was tuned using various electrolytic buffers with different pH values, supporting the variation of the physicochemical characteristics of ERGO discussed in this work. Besides, this study highlights the scope of an interference-free

• nonenzymatic approach through electrochemical nanosensing which can also be used in other biosensing applications. Experimental Chemicals The chemicals used in this work are summarized in Supporting Information File 1, Table S1. Sodium dihydrogen phosphate was used to prepare phosphate buffer saline (pH 4.6

• , 7.4, 9). Acetate buffer (20 mM, pH 4.5), and Britton–Robinson (BR) buffer (40 mM, pH 4) consisting of phosphoric acid, boric acid, and acetic acid were also prepared. Synthesis of graphene oxide Graphene oxide was synthesized from graphite powder using a modified Hummer’s method [30][31]. In detail

Design and selection of peptides to block the SARS-CoV-2 receptor binding domain by molecular docking

• Kendra Ramirez-Acosta,
• Ivan A. Rosales-Fuerte,
• J. Eduardo Perez-Sanchez,
• Alfredo Nuñez-Rivera,
• Josue Juarez and
• Ruben D. Cadena-Nava

Beilstein J. Nanotechnol. 2022, 13, 699–711, doi:10.3762/bjnano.13.62

• , peptides with great affinity to the RBD were selected. The most common amino acids involved in the recognition of the RBD were identified to design novel peptides based on the number of hydrogen bonds that were formed. At physiological pH, these peptides are almost neutral and soluble in aqueous media

• temporin B and lysozyme (61–80). The net charge calculated for the OAPs varies according to the number of negatively and positively charged amino acids present in the primary structure. The net charge values are in the range of −3.9 to 2.9 at pH 7. The OAPs were selected based on an absolute value of the

• electrical net charge smaller than 3.9 (|charge| ≤ 3.9, which is the net charge of ACE2), to avoid possible cytotoxic effects [54][55]. Given that, at physiological pH, the RBD active region is positively charged, it could be assumed that negatively charged peptides, such as sesquin and MVL (74–87) (Figure

Sodium doping in brookite TiO₂ enhances its photocatalytic activity

• Boxiang Zhuang,
• Honglong Shi,
• Honglei Zhang and
• Zeqian Zhang

Beilstein J. Nanotechnol. 2022, 13, 599–609, doi:10.3762/bjnano.13.52

• . Then 1.5 mL of TBOT was slowly dropped into the solution to form a transparent yellow sol by vigorously stirring for a full reaction between TBOT and oxalic acid. The pH value of the sol was adjusted to 10 by using 2 mol/L of NaOH solution. After stirring for another 1 h, the sol was transferred into a

• 100 mL Teflon-lined autoclave and heated at 180 °C for 8 h. The white precipitate was collected by centrifugation (8000 rpm, 10 min), washed to a neutral pH with distilled water and absolute ethanol, and then dried at 80 °C. To inspect the effect of the calcinating temperature on the structure of the

A new method for obtaining the magnetic shape anisotropy directly from electron tomography images

• Cristian Radu,
• Ioana D. Vlaicu and
• Andrei C. Kuncser

Beilstein J. Nanotechnol. 2022, 13, 590–598, doi:10.3762/bjnano.13.51

• nanoparticle system. Experimental For the preparation of the magnetite MNPs, the following starting materials were used as purchased: FeSO4·7H2O (Merck, 99.5%), hexadecyltrimethylammonium bromide (CTAB, 99+%, Acros Organics), NaOH (puriss p.a., ACS reagent, reag. Ph. Eur., K < 0.02%, ≥98%, pellets), NH4OH (for

Detection and imaging of Hg(II) in vivo using glutathione-functionalized gold nanoparticles

• Gufeng Li,
• Shaoqing Li,
• Rui Wang,
• Min Yang,
• Lizhu Zhang,
• Yanli Zhang,
• Wenrong Yang and
• Hongbin Wang

Beilstein J. Nanotechnol. 2022, 13, 549–559, doi:10.3762/bjnano.13.46

• mentioning here that the pH value of the reaction systems played an important role in the synthesis of GSH-Rh6G2. Rh6G2, as an ideal candidate for controlled-release molecular systems, shows little fluorescence (Figure 1b). In the absence of GNPs, the conjugation of GSH-Rh6G2 yields obvious fluorescence. The

• S1, Supporting Information File 1) [42]. The final product of the reaction between Rh6G2 and GSH was proved by TOF-MS analysis (Figure S2, Supporting Information File 1). By adjusting the pH value from an unadjusted slightly acidic environment to pH 7, a significant decrease in the fluorescence of

• first six hours as shown in Figure 4a. Furthermore, the pH value is critical regarding the fluorescence intensity. GNPs-GSH-Rh6G2 displayed a large change in the fluorescence intensity in the pH range from 1 to 5 (Figure 4b). This indicates that Rh6G2 tends to be protonated at low pH values, which

Stimuli-responsive polypeptide nanogels for trypsin inhibition

• Petr Šálek,
• Jana Dvořáková,
• Sviatoslav Hladysh,
• Diana Oleshchuk,
• Ewa Pavlova,
• Jan Kučka and
• Vladimír Proks

Beilstein J. Nanotechnol. 2022, 13, 538–548, doi:10.3762/bjnano.13.45

• biocompatible Nα-ʟ-lysine-grafted α,β-poly[(2-propyne)-ᴅ,ʟ-aspartamide-ran-(2-hydroxyethyl)-ᴅʟ-aspartamide-ran-(2-(4-hydroxyphenyl)ethyl)-ᴅʟ-aspartamide] (Nα-Lys-NG). Both nanogels were prepared by HRP/H2O2-mediated crosslinking in inverse miniemulsions with pH and temperature-stimuli responsive behavior

• acid-labile cholesteryl-modified pullulan nanogel that formed a complex with loaded bovine serum albumin and released it under acidic conditions [17]. Landfester et al. used a bio-orthogonal reaction to fabricate a dextran nanogel with pH-responsive hydrazine linkages allowing for a controlled release

• biodegradable PHEG-Tyr and biocompatible and non-biodegradable Nα-Lys-NG polypeptide precursors by HRP/H2O2-mediated crosslinking in inverse miniemulsion for the delivery of AAT. Both prepared polypeptide nanogels demonstrate stimuli-responsive behavior under different pH values and temperatures. After

Influence of thickness and morphology of MoS₂ on the performance of counter electrodes in dye-sensitized solar cells

• Lam Thuy Thi Mai,
• Hai Viet Le,
• Ngan Kim Thi Nguyen,
• Van La Tran Pham,
• Thu Anh Thi Nguyen,
• Nguyen Thanh Le Huynh and
• Hoang Thai Nguyen

Beilstein J. Nanotechnol. 2022, 13, 528–537, doi:10.3762/bjnano.13.44

• exhibited two redox couple peaks at −0.34 V/−0.76 V and −0.77 V/−1.34 V attributed to the redox reactions of Mo7O246− and MoO42− ions, respectively [27]. The presence of MoO42− ions is due to the equilibrium in Equation 3, which occurs in acidic solution of (NH4)6Mo7O24 (the pH here is about 4.3). The CV

• ) and Na2S in acidic media (adjusted to pH 6) is very favorable to the preparation of MoS42− precursor solution. In this work, the optimal concentration ratio of (NH4)2Mo7O24 (mM) to Na2S (g/L) was found to be 1:6 (data not shown). It can be seen from the CV curve of the mixture solution that the

• )6Mo7O24 (x mM) and Na2S (y g·L−1) in distilled water, the pH of the solution was adjusted to 6.0 using a 20% (v/v) H2SO4 solution, KCl (0.1 M) was used as the supporting electrolyte. The concentration ratio between (NH4)2Mo7O24 and Na2S was kept constant (x/y = 1:6) with different concentration levels

Ciprofloxacin-loaded dissolving polymeric microneedles as a potential therapeutic for the treatment of S. aureus skin infections

• Sharif Abdelghany,
• Walhan Alshaer,
• Yazan Al Thaher,
• Maram Al Fawares,
• Amal G. Al-Bakri,
• Saja Zuriekat and
• Randa SH. Mansour

Beilstein J. Nanotechnol. 2022, 13, 517–527, doi:10.3762/bjnano.13.43

• isocratic composition of 0.025 M phosphoric acid (pH 3.0 ± 0.1) previously adjusted with triethylamine/acetonitrile (80:20 v/v), eluted at a flow rate of 1.5 mL/min. The injection volume was 20 µL. The drug concentration was then determined according to a calibration curve. The calibration curve was plotted

• × phosphate-buffered saline (PBS), pH 7.4, for 15 min. A section of full-thickness human skin was placed, with the stratum corneum facing upward, onto a piece of tissue paper soaked with PBS in a weighing boat. CIP_MN1 were adhered to a piece of plastic tape and manually applied to the skin. To prevent the

Design and characterization of polymeric microneedles containing extracts of Brazilian green propolis

• Camila Felix Vecchi,
• Rafaela Said dos Santos,
• Jéssica Bassi da Silva and
• Marcos Luciano Bruschi

Beilstein J. Nanotechnol. 2022, 13, 503–516, doi:10.3762/bjnano.13.42

• final dispersions were filtered through grade-3 filter paper [44][45]. The pH determination was performed using a pHmeter calibrated with buffer solutions. The relative density of the extract was determined using a pycnometer calibrated at 20 °C in a controlled temperature environment (20 °C). To

Ethosomal (−)-epigallocatechin-3-gallate as a novel approach to enhance antioxidant, anti-collagenase and anti-elastase effects

• Çiğdem Yücel,
• Gökçe Şeker Karatoprak,
• Sena Yalçıntaş and
• Tuğba Eren Böncü

Beilstein J. Nanotechnol. 2022, 13, 491–502, doi:10.3762/bjnano.13.41

• regarding organoleptic properties, pH values, and viscosity. Stability studies were conducted for three months and changes in characterization parameters and residual EGCG content of ETHs were examined. Besides, for ETHG, organoleptic properties, pH values (every two weeks), and viscosity (first and twelfth

• obtained in the F3-coded ETH. Afterward, the ethosomal gel formulation was prepared by dispersing the F3 formulation in 1% (w/v) Carbopol 980 gel. Next, its organoleptic properties (i.e., color and homogeneity), viscosity and rheological properties, and pH values were evaluated. It was found suitable to

• use Carbopol 980 as the gelling agent at a ratio of 1:1 (v/v) due to its suitable organoleptic properties, pH value, viscosity, and its ability to homogeneously mix with the ethosome. A transparent, homogeneous, and smooth ethosomal gel system with a skin-compatible pH value (5.60) was obtained (Table

Zinc oxide nanostructures for fluorescence and Raman signal enhancement: a review

• Ioana Marica,
• Fran Nekvapil,
• Maria Ștefan,
• Cosmin Farcău and
• Alexandra Falamaș

Beilstein J. Nanotechnol. 2022, 13, 472–490, doi:10.3762/bjnano.13.40

• nanotetrapods [26]. Size and shape of the ZnO NPs depend on the type of precursor salts used (e.g., chlorides, sulfates, nitrates, or perchlorates), the molar ratio between reagents, the reaction temperature, the pH value, the ionic concentration of the medium, and other reaction parameters. The main advantage

Tunable superconducting neurons for networks based on radial basis functions

• Andrey E. Schegolev,
• Nikolay V. Klenov,
• Sergey V. Bakurskiy,
• Igor I. Soloviev,
• Mikhail Yu. Kupriyanov,
• Maxim V. Tereshonok and
• Anatoli S. Sidorenko

Beilstein J. Nanotechnol. 2022, 13, 444–454, doi:10.3762/bjnano.13.37

• = 1 μm, and total thickness d = 80 nm (this corresponds to the spacer thickness ds =5 nm) the estimated kinetic inductance is about 7 pH in the closed state and about 15 pH in the open state. For comparison, the geometric inductance of such a strip is of the order of 1 pH. Conclusion We have

A non-enzymatic electrochemical hydrogen peroxide sensor based on copper oxide nanostructures

• Irena Mihailova,
• Vjaceslavs Gerbreders,
• Marina Krasovska,
• Eriks Sledevskis,
• Valdis Mizers,
• Andrejs Bulanovs and
• Andrejs Ogurcovs

Beilstein J. Nanotechnol. 2022, 13, 424–436, doi:10.3762/bjnano.13.35

• = 0 V vs Ag/AgCl and a scan rate of 100 mV/s. As buffer solution, 0.1 M NaOH (pH 12.7) was used. For the determination of H2O2, 0.1, 0.25, 0.5, 0.65, 0.85, 1, and 5 mM concentrations were used. Measurements were carried out five times for each of the indicated concentrations, and the curves in the

• following sections show the averaged data from all measurements. To determine the optimal scanning parameters that provide the maximum sensitivity of the sensor, the dependence of the electrochemical response on the pH of the buffer solution and on the scanning speed was studied. Impedance spectroscopy was

• pH of the buffer solution and on the pulse frequency was studied. Current response study For the current response study (i–t measurement), a constant voltage U = −0.7 V vs Ag/AgCl was applied to the cell and the current was measured. 0.1 M NaOH was used as buffer solution. The measurement was started

Alcohol-perturbed self-assembly of the tobacco mosaic virus coat protein

• Ismael Abu-Baker and
• Amy Szuchmacher Blum

Beilstein J. Nanotechnol. 2022, 13, 355–362, doi:10.3762/bjnano.13.30

• and prevent the formation of helical rods at low pH. A high alcohol content favours stacked disk assemblies and large rafts, while a low alcohol concentration favours individual disks and short stacks. These effects appear to be caused by the hydrophobicity of the alcohol additive, with isopropyl

• range of different structures depending mainly on pH and ionic strength (Figure 1). Above neutral pH and at low to moderate ionic strength, the protein exists primarily as a mixture of monomers and small oligomers. This mixture is known as A-protein [17]. Around pH 6.5–7.0, TMV-cp assembles into achiral

• bilayer disks composed of 17 monomers per layer, 18 nm in diameter with a 4 nm central channel. At high ionic strength and non-acidic pH, these disks can stack on top of each other to form non-helical, rod-like assemblies. There are several known disk aggregates that can be difficult to distinguish

A broadband detector based on series YBCO grain boundary Josephson junctions

• Egor I. Glushkov,
• Alexander V. Chiginev,
• Leonid S. Kuzmin and
• Leonid S. Revin

Beilstein J. Nanotechnol. 2022, 13, 325–333, doi:10.3762/bjnano.13.27

• (Z) = RL, dIm(Z)/dω = 2LL, and . For the serial resonance at 250 GHz, RL = 43 Ω, LL = 500 pH, and CL = 0.8 fF. Figure 5, right, shows the current–voltage characteristics (IVCs) of a single junction with the antenna under the influence of an external signal. A bias current regime with the optimum

The effect of metal surface nanomorphology on the output performance of a TENG

• Yiru Wang,
• Xin Zhao,
• Yang Liu and
• Wenjun Zhou

Beilstein J. Nanotechnol. 2022, 13, 298–312, doi:10.3762/bjnano.13.25

• of a metal and a polymer. There are different charge densities on different kinds of metal surface nanomorphology, which significantly influences the output performance of the TENG. Copper samples with different nanomorphology were obtained by controlling pH value, current density, electrolyte

• freely. Therefore, there is no high charge density on the tip surface of the polymer surface. Here, size and morphology of nanoscale copper were controlled by adjusting current density, temperature, pH value, and solution concentration during electrodeposition. The effects of different morphologies and

• and copper oxide was activated at the same time. After acid oil removal, the copper sheets were washed with deionized water at 25 and 50 °C, and the residuals from the previous process were cleaned to avoid polluting the electroplating solution. Different pH values were set using 1 M sulfuric acid

Coordination-assembled myricetin nanoarchitectonics for sustainably scavenging free radicals

• Xiaoyan Ma,
• Haoning Gong,
• Kenji Ogino,
• Xuehai Yan and
• Ruirui Xing

Beilstein J. Nanotechnol. 2022, 13, 284–291, doi:10.3762/bjnano.13.23

• , and allergens [17]. In spite of the tremendous potential, Myr possesses the same shortcomings as many hydrophobic small molecules, namely low bioavailability, poor water solubility and rapid degradation at pH > 6.8, which limits its clinical therapeutic potential [22]. GSH consists of glycine

• quantitative stoichiometry analysis. The quantitative component analysis by UV–vis and ICP-OES proved that the molar ratio of Myr/GSH/Zn2+ was close to 1:1:1 (Supporting Information File 1, Table S1 and Figure S1). The UV–vis absorption spectra of pure Myr dispersed in 0.1 M NaOH (pH 13), Myr/Zn2+ complex (pH

• 5.5), and MZG nanoparticles (pH 5.5) were measured. The UV–vis absorption spectrum of MZG nanoparticles exhibited a blue shift at 550 nm, compared with Myr/Zn2+, which was assigned to the charge transfer between GSH and Zn2+ (Figure 2c). These results demonstrated that Zn2+ as the coordination

Systematic studies into uniform synthetic protein nanoparticles

• Nahal Habibi,
• Ava Mauser,
• Jeffery E. Raymond and
• Joerg Lahann

Beilstein J. Nanotechnol. 2022, 13, 274–283, doi:10.3762/bjnano.13.22

• water and ethanol with a 9:1 (v/v) ratio. The exception was insulin and mucin-based SPNPs. Because insulin has poor solubility at neutral pH, acetic acid at 10% (v/v) was added to the solvent mixture to ensure miscibility. Due to its high molecular weight, mucin was used at 2% (w/v). NHS-PEG-NHS