Modeling a multiple-chain emeraldine gas sensor for NH₃ and NO₂ detection

• Hana Sustkova and
• Jan Voves

Beilstein J. Nanotechnol. 2022, 13, 721–729, doi:10.3762/bjnano.13.64

• molecular properties of polyaniline have been studied by quantum mechanical means in [4][8]. The band structure was calculated by Reis et al. [9], together with transmittance, electrical current flow, and charge density. For these calculations, density functional theory (DFT, [10]) based on the generalized

• charge carriers is limited and very small in comparison with macroscopic PANI media. This leads to current saturation. The electric resistance was estimated from the initial linear behavior of the I–V characteristics before saturation. At first, we have computed only models with one PANI chain. We have

• effect of the ammonia gas molecule as well. The resistance increase is higher for the ammonia position near the doped polyaniline nitrogen and lower at the undoped position. Due to higher resistance of the hopping process, the current is flowing mainly through the direct connection of the sensor

Direct measurement of surface photovoltage by AC bias Kelvin probe force microscopy

• Masato Miyazaki,
• Yasuhiro Sugawara and
• Yan Jun Li

Beilstein J. Nanotechnol. 2022, 13, 712–720, doi:10.3762/bjnano.13.63

• (HF2LI with PID option, Zurich Instruments) to generate and control the AC bias. The typical sensitivity of our measurements was estimated to be δV = 1 mV (see Appendix). We simultaneously measured the tunneling current through the I/V converter as scanning tunneling microscopy (STM) [34] to consider the

• of the rutile TiO2(110) surface. Terrace and step structures were observed, and the surface was flat within a single step height of 325 pm [50]. Figure 3b shows the SPV image obtained simultaneously with the AFM image. No tunneling current was detected in the AC-KPFM measurement. The SPV profile is

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

• viruses. Keywords: angiotensin converting enzyme-2 (ACE2); antiviral peptides; hydrogen bonds; molecular docking; SARS-CoV-2 RBD; Introduction The current pandemic due to coronavirus disease-19 (COVID-19), caused by the novel virus SARS-CoV-2, has over 533 million of confirmed cases and over 6.3 million

• site of a given protein, due to the low cost, versatility, and ease to develop [16][17][18]. Current peptide design techniques involve the modification of peptides based on the ACE2 receptor to increase their binding affinity to the SARS-CoV-2 RBD and to prevent the virus from binding onto the ACE2

Nanoarchitectonics of the cathode to improve the reversibility of Li–O₂ batteries

• Hien Thi Thu Pham,
• Jonghyeok Yun,
• So Yeun Kim,
• Sang A Han,
• Jung Ho Kim,
• Jong-Won Lee and
• Min-Sik Park

Beilstein J. Nanotechnol. 2022, 13, 689–698, doi:10.3762/bjnano.13.61

• for lowering the overpotential of the cathode during cycling, even at the high current density of 2,000 mA·g−1. Keywords: cathode composition; electrochemistry; Li–O2 battery; metal–organic framework; nanoarchitectonics; zeolitic imidazolate framework; Introduction Recently, lithium–oxygen batteries

• cathodes at a current density of 50 mA·g−1. All of the cathodes showed a well-defined voltage plateau at ≈2.7 V vs Li/Li+ for Li2O2 formation. The initial discharge capacities of Zn4Co1–C/CNT, Zn1Co1–C/CNT, and Zn1Co4–C/CNT cathodes were measured to be 16,000 mAh·g−1, ≈15,100 mAh·g−1, and ≈17,900 mAh·g−1

• Figure 6d–f. The galvanostatic discharge profiles of ZnxCoy–C/CNT cathodes were recorded with a limited capacity of 500 mAh·g−1 at various current densities (iapp) ranging from 50 to 2,000 mA·g−1. Interestingly, ZnxCoy–C/CNT cathodes exhibited different trends in their rate capability compared with the

Experimental and theoretical study of field-dependent spin splitting at ferromagnetic insulator–superconductor interfaces

• Peter Machon,
• Michael J. Wolf,
• Detlef Beckmann and
• Wolfgang Belzig

Beilstein J. Nanotechnol. 2022, 13, 682–688, doi:10.3762/bjnano.13.60

• the results. However, the theory is not restricted to this case. Thus, we replace the sum over the channel index n in the matrix current conservation with the number of channels, that is, However, in a phenomenological way we assume that, effectively, only a certain fraction r ∈ [0,1] of scattering

A superconducting adiabatic neuron in a quantum regime

• Marina V. Bastrakova,
• Dmitrii S. Pashin,
• Dmitriy A. Rybin,
• Andrey E. Schegolev,
• Nikolay V. Klenov,
• Igor I. Soloviev,
• Anastasiya A. Gorchavkina and
• Arkady M. Satanin

Beilstein J. Nanotechnol. 2022, 13, 653–665, doi:10.3762/bjnano.13.57

• work, we account for this by considering the neuron cell operation in a quantum regime. We investigate the dynamics of this cell in search of conditions that provide the required sigmoid activation function (conversion of the input magnetic flux into the average output current), suitable for the

• in [46] when considering the classical mode of this system. Inductances are normalized to (2πIc/Φ0), where Ic is the critical current of the Josephson junction and Φ0 is the magnetic flux quantum. The inertial properties of the system are due to the junction capacitance, which, along with the

• critical current Ic, determines the plasma frequency of the JJ, In this case, the dissipative properties of the system are determined by the Josephson characteristic frequency ωc = 2eRIcℏ (here, R and C are the normal state resistance and capacitance of the Josephson junction, respectively). Dynamic

Antibacterial activity of a berberine nanoformulation

• Hue Thi Nguyen,
• Tuyet Nhung Pham,
• Anh-Tuan Le,
• Nguyen Thanh Thuy,
• Tran Quang Huy and
• Thuy Thi Thu Nguyen

Beilstein J. Nanotechnol. 2022, 13, 641–652, doi:10.3762/bjnano.13.56

• studies have shown evidence that BBR and its derivatives can also fight severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is a current concern worldwide [21][22][23]. The water solubility of phytochemicals plays an important role in the effectiveness of disease treatment. A poor water

Fabrication and testing of polymer microneedles for transdermal drug delivery

• Vahid Ebrahiminejad,
• Zahra Faraji Rad,
• Philip D. Prewett and
• Graham J. Davies

Beilstein J. Nanotechnol. 2022, 13, 629–640, doi:10.3762/bjnano.13.55

• and manufactured to address current limitations for mimicking skin in vivo conditions. Finite element analysis (FEA) was developed to simulate single MN insertion into a multilayered skin model and validated experimentally using a commercial Pen Needle as a model for the thermoplastic MNs. Margins of

• safety for the current MN design demonstrated its potential for transdermal drug delivery and fluid sampling. Experimental results indicated significant penetration improvements using the prototype applicator, which produced array penetration efficiencies as high as >92%, depending on the impact velocity

• multistage fabrication processes with high production costs [7]. Similarly, laser ablation and lithography techniques are costly, requiring extended production time [8]. To overcome the current manufacturing limitations, MNs might be fabricated cost-effectively, with high precision and accuracy, using 3D

Comparative molecular dynamics simulations of thermal conductivities of aqueous and hydrocarbon nanofluids

• Adil Loya,
• Antash Najib,
• Fahad Aziz,
• Asif Khan,
• Guogang Ren and
• Kun Luo

Beilstein J. Nanotechnol. 2022, 13, 620–628, doi:10.3762/bjnano.13.54

• nanoparticles can enhance the properties of both polar and nonpolar fluids. In the current paper, dispersions of nanoparticles were carried out in hydrocarbon and aqueous-based fluids using molecular dynamic simulations (MDS). The MDS results have been validated using the autocorrelation function and previous

• nanoparticles with various volumetric concentrations in the base fluid (i.e., water) and obtained data with a similar temperature interval as obtained in the current research (i.e., above 0.71–0.92 W·m−1·K−1) [44]. The MDS results showed that adding CuO nanoparticles enhanced the thermal conductivity of water

• modified system. The high conductivity of water-based nanofluids is due to the higher thermal conductivity of the base fluid itself. However, these results are further explained in the subsequent section with references to heat and current autocorrelation functions (HACF) as represented in Figure 4b

Approaching microwave photon sensitivity with Al Josephson junctions

• Andrey L. Pankratov,
• Anna V. Gordeeva,
• Leonid S. Revin,
• Dmitry A. Ladeynov,
• Anton A. Yablokov and
• Leonid S. Kuzmin

Beilstein J. Nanotechnol. 2022, 13, 582–589, doi:10.3762/bjnano.13.50

• power, whose presence can be observed only in the switching distributions and in the shorter lifetime of the superconducting state. The used experimental setup is the same as in [7], except for the measured sample. In [7], the critical current of the sample was very low, and the phase diffusion regime

• was noticeably pronounced. The sample considered here has a much higher critical current, and the phase diffusion does not appear. As a result, the theoretical estimates based on the BCS theory for critical currents and Kramers’ theory for escape times are well applicable. Furthermore, the analysis of

• the experiment is done with a more general theory, which considers the absorption probabilities of different numbers of photons. The time traces of setting a current and an external microwave signal to measure the switching probability as a function of power are shown in Figure 1c. First, the current

Effects of substrate stiffness on the viscoelasticity and migration of prostate cancer cells examined by atomic force microscopy

• Xiaoqiong Tang,
• Yan Zhang,
• Jiangbing Mao,
• Yuhua Wang,
• Zhenghong Zhang,
• Zhengchao Wang and
• Hongqin Yang

Beilstein J. Nanotechnol. 2022, 13, 560–569, doi:10.3762/bjnano.13.47

• pancreatic and hepatocellular carcinoma have also found that a stiffer ECM promotes EMT [13][14]. Therefore, the study of ECM stiffness has important implications for tumour metastasis. For prostate cancer, the current clinical approach to improving the positive biopsy rate is to incorporate ultrasound

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

• and Na2S in KCl electrolyte solution. To study the redox behavior of the solution, the CV curves for each component and the mixture solutions were recorded in the potential range from −1.5 V to 1.0 V (Figure 1). The blank KCl electrolyte exhibits a straight line around zero current, while the

• potential compared to that of the (NH4)2Mo7O24 solution, see the insert in Figure 2a). The current density of the CV curves increases with the increase of precursor solution concentration. This allows one to predict that the thickness of MoS2 film will be increased in the order: solution 1.25 < solution 2.5

• /cathode peak potentials (EpOx1, EpRed1), peak-to-peak voltage separation (Epp), and anode/cathode peak current densities (JOx1, JRed1) were calculated and presented in Table 1. The Epp value for MoS2 CEs was slightly larger than that of Pt CE confirming their excellent electrocatalytic activity. The JRed1

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

• tissue and skin infections (STSI) caused by S. aureus [13][14][15][16]. However, the therapeutic dose of ciprofloxacin upon using conventional delivery systems is relatively high and associated with adverse effects, which partially contributed to its current limited use in the management of S. aureus

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

• different plant extracts other than EGCG [15]. In this current study, we aimed to develop ethosomal formulations for the use of EGCG in cosmetics due to its widely known strong antioxidant effect, which has been emphasized in many studies. In addition, we focused on enhancing the long-term antioxidant

• penetration through the skin due to the ethanol in their composition [22]. In the current study, ethosomal formulations of EGCG with strong antioxidant properties were developed and their efficiencies were assessed and compared to the EGCG solution form. Six different ethosomal formulations were developed and

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

Investigation of electron-induced cross-linking of self-assembled monolayers by scanning tunneling microscopy

• Patrick Stohmann,
• Sascha Koch,
• Yang Yang,
• Christopher David Kaiser,
• Julian Ehrens,
• Jürgen Schnack,
• Niklas Biere,
• Dario Anselmetti,
• Armin Gölzhäuser and
• Xianghui Zhang

Beilstein J. Nanotechnol. 2022, 13, 462–471, doi:10.3762/bjnano.13.39

• beam current was measured by using a Faraday cup. The SAMs were irradiated with beam currents ranging from 200–600 pA. Prior to electron irradiation, the STM tip was retracted and moved away from the surface location of interest, such that the electrons could pass the tip and reach the surface location

• the surface normal, thus enabling to control the position of the STM tip by SEM. All STM data was acquired at room temperature under UHV conditions (chamber pressure <10−10 mbar). The STM was operated in constant-current mode with tunneling currents of 10–100 pA and sample biases between −1.2 to −0.4

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

• the flux quantum Φ0; currents are normalized to the critical current of the Josephson junctions IC; inductances are normalized to the characteristic inductance 2πLIC/Φ0, times are normalised to the characteristic time tC = Φ0/(2πVC) (VC is the characteristic voltage of a Josephson junction). Equations

• again, we emphasize that variations in the parameters of the circuit within a fairly wide range allow one to change the amplitude and width of the activation function, while maintaining its Gaussian-like shape. The dynamic transfer functions (i.e., the dependencies of the output current on the time

• For neural networks based on the considered G-neurons, tunable elements with linear current-to-flux transformation (linear inductors) and memory properties are extremely important [50][51]. Tunability of the inductance l in Figure 1b allows for an in situ switching between operating modes directly on

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

• spectroscopy and X-ray diffractometry. The resulting nanostructured samples were used for electrochemical determination of the H2O2 content in a 0.1 M NaOH buffer solution using cyclic voltammetry, differential pulse voltammetry, and i–t measurements. A good linear relationship between the peak current and the

• 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

• concentration range of 350–800 µM, and 100 µM for the concentration range of 900–1800 µM. The measurement was carried out with constant stirring using a magnetic stirrer. Interference study A constant voltage U = −0.7 V vs Ag/AgCl was applied to the cell and the current was measured. As buffer solution 0.1 M

A chemiresistive sensor array based on polyaniline nanocomposites and machine learning classification

• Jiri Kroutil,
• Alexandr Laposa,
• Ali Ahmad,
• Jan Voves,
• Vojtech Povolny,
• Ladislav Klimsa,
• Marina Davydova and
• Miroslav Husak

Beilstein J. Nanotechnol. 2022, 13, 411–423, doi:10.3762/bjnano.13.34

• been used for the classification of gas sensor data using a 10-fold cross-validation to reach the highest classification rate. Results and Discussion The sensors layers were investigated by scanning electron microcopy (SEM), Raman spectroscopy, current–voltage and temperature analysis, and gas sensing

• +, characteristic band of the polaron radical cation); (6) 1412 cm−1 (phenazine structures); (7) 1498 cm−1 (C=N of the quinoid nonprotonated diimine units); (8) 1590 cm−1 (C=C stretching vibration of the quinonoid ring) [16][17]. Current–voltage and temperature analysis Figure 3 shows current–voltage

• the PANI. Current–voltage characteristics of active layers. Temperature dependence characteristics of active layers. Schematic diagram of the gas sensing characterizations apparatus. Gas characterization of active layers towards (a) 25 ppm of NH3, (b) 25 ppm of NO2, (c) 25 ppm of CO, (d) 250 ppm of

Electrostatic pull-in application in flexible devices: A review

• Teng Cai,
• Yuming Fang,
• Yingli Fang,
• Ruozhou Li,
• Ying Yu and
• Mingyang Huang

Beilstein J. Nanotechnol. 2022, 13, 390–403, doi:10.3762/bjnano.13.32

• functionality of nanostructures to process external stimuli applied to the device controlling the electrical current [12]. The lower pull-in voltage and the improved durability of the NEM switches require electrode materials with high Young’s modulus, conductivity, and Poisson's ratio. The flexible suspension

• electrode materials include CNTs, GR, and silicon/germanium nanowires. CNT-NEM switches CNTs are an ideal flexible material for NEM electrodes because of the high aspect ratio, current density, and excellent tensile strength. In 2000, Rueckes et al. [13] observed the electromechanical conversion in CNTs for

• cross section of 14 µm × 400 nm. The gap is 300 nm, and the pull-in voltage is 70 V. As the width is reduced to 200 nm and the gap is reduced to 100 nm, the pull-in voltage is reduced to 5 V. The switching current ratio is greater than 106, and the number of life cycles is greater than 105. Jasulaneca

Micro- and nanotechnology in biomedical engineering for cartilage tissue regeneration in osteoarthritis

• Zahra Nabizadeh,
• Mahmoud Nasrollahzadeh,
• Hamed Daemi,
• Mohamadreza Baghaban Eslaminejad,
• Ali Akbar Shabani,
• Mehdi Dadashpour,
• Majid Mirmohammadkhani and
• Davood Nasrabadi

Beilstein J. Nanotechnol. 2022, 13, 363–389, doi:10.3762/bjnano.13.31

Selected properties of Al_xZn_yO thin films prepared by reactive pulsed magnetron sputtering using a two-element Zn/Al target

• Witold Posadowski,
• Artur Wiatrowski,
• Jarosław Domaradzki and
• Michał Mazur

Beilstein J. Nanotechnol. 2022, 13, 344–354, doi:10.3762/bjnano.13.29

• discharge power) was equal to 400 W. The power supply is the medium frequency pulsed power supply, inducing a pulsed magnetron discharge. The output current pulses are sinusoidal with a duration of 10 µs and a stabilized amplitude of 16 A. During each current pulse, with changes in the magnetron discharge

• impedance, the supply output voltage varies to keep the sinusoidal shape of the magnetron current. Since the power supply operates in a pulsed manner (100 kHz), the average output power is controlled via pulse quantity modulation with a gating period of about 1 ms. The target–substrate distance was dS–T

Controllable two- and three-state magnetization switching in single-layer epitaxial Pd_1−xFe_x films and an epitaxial Pd_0.92Fe_0.08/Ag/Pd_0.96Fe_0.04 heterostructure

• Igor V. Yanilkin,
• Amir I. Gumarov,
• Gulnaz F. Gizzatullina,
• Roman V. Yusupov and
• Lenar R. Tagirov

Beilstein J. Nanotechnol. 2022, 13, 334–343, doi:10.3762/bjnano.13.28

• .13.28 Abstract We have investigated the low-temperature magnetoresistive properties of a thin epitaxial Pd0.92Fe0.08 film at different directions of the current and the applied magnetic field. The obtained experimental results are well described within an assumption of a single-domain magnetic state of

• degrees of freedom to control the critical current of MJJs [10] or SSVs [6], or current–phase relations in MJJs [11][12]. In particular, the spin-valve structure embedded into a MJJ can serve as an actuator for switching the MJJ between critical current modes or flipping its current–phase relation, thus

• Pd0.92Fe0.08 film at different in-plane orientations of the magnetic field was studied by measuring the anisotropic magnetoresistance (AMR) using the four-probe method. For this purpose, the Pd0.92Fe0.08 film was cut with a diamond saw into stripe-like pieces. In the first sample the current flowed along the

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

• –frequency characteristic, beam pattern, and fraction of the absorbed power in each Josephson junction were investigated. Based on the obtained results, a numerical simulation of one-dimensional arrays was carried out. The dc characteristics of the detector were calculated, that is, current–voltage

• –frequency characteristic (AFC) less smooth. Since the purpose of the current work was to develop a broadband system, for further consideration we chose an antenna with the most uniform AFC, sacrificing the maximum absorbed power in resonances. This is the antenna in Figure 1a with the parameters α = 30°, β

• there are N junctions connected in series one after another with a common load in parallel to all junctions (see Figure 5, left). The circuit equations describing the current–voltage relation are [27][28][29]: where ϕi is the Josephson phase in the i-th junction, and the overdot denotes differentiation

Interfacial nanoarchitectonics for ZIF-8 membranes with enhanced gas separation

• Season S. Chen,
• Zhen-Jie Yang,
• Chia-Hao Chang,
• Hoong-Uei Koh,
• Sameerah I. Al-Saeedi,
• Kuo-Lun Tung and
• Kevin C.-W. Wu

Beilstein J. Nanotechnol. 2022, 13, 313–324, doi:10.3762/bjnano.13.26

• current membrane separation market in chemical engineering is dominated by polymeric membranes because of their low cost, ease of production, and mechanical flexibility [6][7][8][9]. However, applications of polymeric membranes in the separation processes are limited by their short lifetime and inferior