Differences in surface chemistry of iron oxide nanoparticles result in different routes of internalization

• Barbora Svitkova,
• Vlasta Zavisova,
• Veronika Nemethova,
• Martina Koneracka,
• Miroslava Kretova,
• Filip Razga,
• Monika Ursinyova and
• Alena Gabelova

Beilstein J. Nanotechnol. 2021, 12, 270–281, doi:10.3762/bjnano.12.22

• of a pulmonary disease, where the airway–mucus barrier is difficult to penetrate, nanoparticles in the size range of 200 nm are more effective in mucus penetration [20][37]. The effect of surface chemistry on the mechanism of NPs uptake is, however, not sufficiently understood yet. Understanding the

Extended iron phthalocyanine islands self-assembled on a Ge(001):H surface

• Rafal Zuzak,
• Marek Szymonski and
• Szymon Godlewski

Beilstein J. Nanotechnol. 2021, 12, 232–241, doi:10.3762/bjnano.12.19

• holds also for layered materials. Single-molecule prototypes or molecular nanostructures are often prepared on metals, which usually provide a sufficiently low diffusion barrier for efficient self-assembly and simultaneously allow for in-depth analysis through atomically precise tools from the family of

• between the island and the surface and also a low barrier for island displacement. Further, from the analysis of the apparent height of the molecular island, an upright orientation of the molecules can be inferred. Such a behavior has been frequently reported for substrates on which the interaction

Paper-based triboelectric nanogenerators and their applications: a review

• Jing Han,
• Nuo Xu,
• Yuchen Liang,
• Mei Ding,
• Junyi Zhai,
• Qijun Sun and
• Zhong Lin Wang

Beilstein J. Nanotechnol. 2021, 12, 151–171, doi:10.3762/bjnano.12.12

• transferred charges and the corresponding CE mechanism in TENGs. The results shown in [90] suggest that the electron transfer dominates the CE process. The charge retention ability is attributed to the intrinsic potential barrier heights of the different materials, which can prevent the charge dissipation. As

• material B by an enlarged energy barrier. This leads to A and B being positively and negatively charged, respectively (Figure 3-iii). As the temperature rises, the transferred electrons in B tend to more easily escape from the potential well and to be thermionically emitted into the air, leading to a

• decreases in a low RH condition. As the RH increases, the hydroxy groups of the first physisorbed layer bond to water molecules, through hydrogen bonding, which also permeate into the interlayers of GO. The gradually absorbed water layer creates a uniform barrier layer for the induction of positive charges

A review on the green and sustainable synthesis of silver nanoparticles and one-dimensional silver nanostructures

• Sina Kaabipour and
• Shohreh Hemmati

Beilstein J. Nanotechnol. 2021, 12, 102–136, doi:10.3762/bjnano.12.9

• biosynthesis occurs outside of cells due to the presence of biomolecules [191], which depends on the type of cell culture used. For instance, cell-wall deficient cells are typically more inclined towards intracellular biosynthesis as the cell-wall is known to act as a barrier for the diffusion of metal cations

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

• found up to 24 h and even after 168 h of exposure the changes in the blocking behaviour were still minimal. This behaviour was also observed for protection against direct reduction of FTO. Keywords: Al2O3; atomic layer deposition (ALD); barrier properties; corrosion; electrochemistry; FTO

• 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

• that of pure FTO is higher than three. This means that there are B-type defects in the barrier film. These defects cause not only the delamination of the Al2O3 film from the FTO substrate, but also a slowdown of the charge-transfer kinetics (accompanied by a strong increase in ΔEpp). The Table 1 shows

Piezotronic effect in AlGaN/AlN/GaN heterojunction nanowires used as a flexible strain sensor

• Jianqi Dong,
• Liang Chen,
• Yuqing Yang and
• Xingfu Wang

Beilstein J. Nanotechnol. 2020, 11, 1847–1853, doi:10.3762/bjnano.11.166

• ITO transparent electrodes were patterned and deposited onto the two ends of the AlGaN/AlN/GaN heterojunction NWs to eliminate the impact of the Schottky barrier. In addition, they fixed the NW to the flexible PET substrate. A schematic of the equipment (electric one-dimensional translation stage) for

Unravelling the interfacial interaction in mesoporous SiO₂@nickel phyllosilicate/TiO₂ core–shell nanostructures for photocatalytic activity

• Bridget K. Mutuma,
• Xiluva Mathebula,
• Isaac Nongwe,
• Bonakele P. Mtolo,
• Boitumelo J. Matsoso,
• Rudolph Erasmus,
• Zikhona Tetana and
• Neil J. Coville

Beilstein J. Nanotechnol. 2020, 11, 1834–1846, doi:10.3762/bjnano.11.165

• photocatalysts is rarely reported. Nickel-based nanomaterials are of great interest for photocatalytic activity owing to their low cost, high optical absorption coefficients, and low bandgap energies [29][30][31]. Most importantly, the formation of a Schottky barrier between nickel species and titania can

Absorption and photoconductivity spectra of amorphous multilayer structures

• Oxana Iaseniuc and
• Mihail Iovu

Beilstein J. Nanotechnol. 2020, 11, 1757–1763, doi:10.3762/bjnano.11.158

• applied field becomes higher than the internal electrical field. For amorphous semiconductors the barrier height of an Al–semiconductor contact, with a work function of φm = 4.18 eV, is φb = 0.40–0.75 eV [14][17]. This is very important from a practical point of view, because there is the possibility to

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

• from PEI make the CNTs much more soluble in aqueous solution and thus improve their biocompatibility [37]. Furthermore, surface modification with PEGylated agents or positively charged groups can protect the nanocarriers by providing a steric barrier from being recognized and captured by the

Seebeck coefficient of silicon nanowire forests doped by thermal diffusion

• Shaimaa Elyamny,
• Elisabetta Dimaggio and
• Giovanni Pennelli

Beilstein J. Nanotechnol. 2020, 11, 1707–1713, doi:10.3762/bjnano.11.153

• penetration of the doping species (phosphorous, in our case) into the silicon. It requires an oxidizing environment, at least in a first preliminary phase, to grow a thin SiO2 layer at the surface as a barrier for the doping species, forcing the diffusion into silicon. In the specific case of thermoelectric

Out-of-plane surface patterning by subsurface processing of polymer substrates with focused ion beams

• Serguei Chiriaev,
• Luciana Tavares,
• Vadzim Adashkevich,
• Arkadiusz J. Goszczak and
• Horst-Günter Rubahn

Beilstein J. Nanotechnol. 2020, 11, 1693–1703, doi:10.3762/bjnano.11.151

• energy barrier for material expansion and relaxation. This entirely phenomenological model is consistent with the conclusions drawn in a previous study [25], in which swelling was observed in PDMS samples irradiated with a 2 MeV proton beam. In that the case, the irradiated surface was fabricated by

A self-powered, flexible ultra-thin Si/ZnO nanowire photodetector as full-spectrum optical sensor and pyroelectric nanogenerator

• Liang Chen,
• Jianqi Dong,
• Miao He and
• Xingfu Wang

Beilstein J. Nanotechnol. 2020, 11, 1623–1630, doi:10.3762/bjnano.11.145

• -axis of the ZnO NWs (Figure 2, middle). Because the direction of the pyroelectric electric field (Epy) is the same as Eb and the barrier height decreases at the heterojunction interface due to the generation of a negative polarization potential, the total electric field in the depletion zone increases

PTCDA adsorption on CaF₂ thin films

• Philipp Rahe

Beilstein J. Nanotechnol. 2020, 11, 1615–1622, doi:10.3762/bjnano.11.144

• statistical artefact. However, it is also noteworthy that the intermediate minimum in the distribution is less pronounced in measurements performed after PTCDA deposition on cooled samples, which suggests an increased barrier at the estimated sample temperature of 140 K to arrive in the optimum adsorption

Detecting stable adsorbates of (1S)-camphor on Cu(111) with Bayesian optimization

• Jari Järvi,
• Patrick Rinke and
• Milica Todorović

Beilstein J. Nanotechnol. 2020, 11, 1577–1589, doi:10.3762/bjnano.11.140

• minima, not only the global energy minimum. Local minima and barrier extraction Once the PES is converged, we data-mine the surrogate model. We extract the lowest energy minima, which we equate with the lowest-energy adsorbate structures. The minima are detected using the built-in local minima search

• upper limits to the true barriers. However, even qualitative accuracy in barrier evaluations suffices to identify the least mobile structures, which are the best candidates when compared to experimentally observed structures. We will return to energy barriers and our way of estimating them in the

• minimum at (θ, φ, ω) = (−3, 7, −3)°, and an energy barrier of 0.1 eV for the rotation of the methyl groups. Given this barrier, the rotation of the methyl groups Δφ away from the global minimum is expected to be small at room temperature. The Arrhenius law predicts that in 50% of the molecules Δφ < 10

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

•  5a) become trapped along isoelectric lines (Figure 5b). The effects of DEP depend on the gradient of the square of the electric field (Figure 5c). The isoelectric line with the lowest magnitude in Figure 5b (i.e., the line passing through the midpoint of the constriction) forms a “barrier” through

Adsorption and self-assembly of porphyrins on ultrathin CoO films on Ir(100)

• Feifei Xiang,
• Tobias Schmitt,
• Marco Raschmann and
• M. Alexander Schneider

Beilstein J. Nanotechnol. 2020, 11, 1516–1524, doi:10.3762/bjnano.11.134

• molecular state at temperatures of 80 K and above prevents the molecules from locking into a compact self-assembled layer at low coverage. When stationary molecules with a rotational potential barrier larger than the diffusion barrier self-assemble, the intermolecular forces guide the molecules to diffuse

• into a state of low-energy at an appropriate bonding distance. This is, for example, observed at low coverage of 2H-DPP on Cu(111) [23]. When, as it appears here, the diffusion and the rotational barrier are of equal magnitude, the intermolecular forces cannot exert their directional influence on the

Antimicrobial metal-based nanoparticles: a review on their synthesis, types and antimicrobial action

• Matías Guerrero Correa,
• Fernanda B. Martínez,
• Cristian Patiño Vidal,
• Camilo Streitt,
• Juan Escrig and
• Carol Lopez de Dicastillo

Beilstein J. Nanotechnol. 2020, 11, 1450–1469, doi:10.3762/bjnano.11.129

• protection to the cell against osmotic rupture and mechanical damage. It is the first barrier against any harmful particles from the environment, such as oxidative molecules. Every type of microorganism has a different cell wall composition: i) fungi and yeast are mainly composed of chitin and

• , slightly attract NPs [158]. In addition, the double membrane acts as a selective physical barrier against hydrophobic compounds, such as detergents and antibiotics. On the other hand, Gram-positive bacteria have a higher permeability, even with a thick layer of peptidoglycan, since the single membrane is

Protruding hydrogen atoms as markers for the molecular orientation of a metallocene

• Linda Laflör,
• Michael Reichling and
• Philipp Rahe

Beilstein J. Nanotechnol. 2020, 11, 1432–1438, doi:10.3762/bjnano.11.127

• ferrocene, the rotational barrier between these conformers amounts to only 0.04 eV in the gas phase [11][12][13], while for substituted ferrocenes the energy barrier values determined in the gas phase amount up to 0.2 eV [14][15][16]. In solution, barrier values of up to 0.7 eV are measured [17][18] and for

• ionised derivates calculations yielded rotational barrier values of up to 1.4 eV [19]. From this class of molecules we investigate the ferrocene derivate 1,1’-ferrocene dicarboxylic acid (FDCA), a ferrocene functionalised with two carboxylic acid moieties. This molecule has been analysed before on Ag(111

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

• glutamate homeostasis and synaptic neurotransmission. Also, glutamate plays an important role in mediating the blood–brain barrier function and can be exploited for clinical translation [38]. It was shown that the conjugation of non-permeable drugs with glutamate may improve the brain delivery of the drug

• [39]. The neuronal release of glutamate modulates the blood–brain barrier function, through activation of N-methyl-ᴅ-aspartate (NMDA) receptors [40]. Glutamate increased intracellular calcium levels in endothelial cells and levels of nitrogen oxide (NO) around microvessels. These results can be

• considered in support of a mechanism of glutamate-induced activation of NMDA receptors in endothelial cells, which leads to calcium signaling and downstream NO production to promote blood–brain barrier permeability [38]. Thus, it may be expected that glutamate-conjugated γ-Fe2O3 nanoparticles can more easily

Effect of localized helium ion irradiation on the performance of synthetic monolayer MoS₂ field-effect transistors

• Jakub Jadwiszczak,
• Pierce Maguire,
• Conor P. Cullen,
• Georg S. Duesberg and
• Hongzhou Zhang

Beilstein J. Nanotechnol. 2020, 11, 1329–1335, doi:10.3762/bjnano.11.117

• the interface at this delivered dose. It may be expected that an increase in the Schottky barrier height will occur if the normally pinned Fermi level [42] is now a function of the physical state of the beam-altered metal–semiconductor interface. Ion beam pre-treatment of the contact region before

Growth of a self-assembled monolayer decoupled from the substrate: nucleation on-command using buffer layers

• Robby Reynaerts,
• Kunal S. Mali and
• Steven De Feyter

Beilstein J. Nanotechnol. 2020, 11, 1291–1302, doi:10.3762/bjnano.11.113

• formation by acting as a physical barrier between the substrate and the assembling moiety, buffer layers are also widely used to study intrinsic electronic properties of functional organic systems such as organic semiconductors [32][33] and films of 1D/2D polymers [34][35][36][37] via electronic decoupling

Gas sorption porosimetry for the evaluation of hard carbons as anodes for Li- and Na-ion batteries

• Yuko Matsukawa,
• Fabian Linsenmann,
• Maximilian A. Plass,
• George Hasegawa,
• Katsuro Hayashi and
• Tim-Patrick Fellinger

Beilstein J. Nanotechnol. 2020, 11, 1217–1229, doi:10.3762/bjnano.11.106

• relate the steep gas uptake to different sizes of pore necks, reflecting a barrier to penetrate the whole pore system. Similar to the case of SSA determination by N2 and CO2 sorption, it is interesting to compare absolute values and relative deviations in the quantification of pore volumes of the RF

Hybridization vs decoupling: influence of an h-BN interlayer on the physical properties of a lander-type molecule on Ni(111)

• Maximilian Schaal,
• Takumi Aihara,
• Marco Gruenewald,
• Felix Otto,
• Jari Domke,
• Roman Forker,
• Hiroyuki Yoshida and
• Torsten Fritz

Beilstein J. Nanotechnol. 2020, 11, 1168–1177, doi:10.3762/bjnano.11.101

• consequences for possible applications in molecular electronic devices. Low work function metals such as Al, Ca or Ba are typically used to achieve a low electron injection barrier, which is necessary to build high-performance n-type organic semiconductors [41]. However, these substrates suffer from a high

• mobility. This additional diffusion barrier thus hampers the molecular self-assembly and can be overcome by a higher substrate temperature during the film growth, which agrees with our structural findings above. Conclusion To summarize, we investigated the influence of an h-BN interlayer on the optical

Scanning tunneling microscopy and spectroscopy of rubrene on clean and graphene-covered metal surfaces

• Karl Rothe,
• Alexander Mehler,
• Nicolas Néel and
• Jörg Kröger

Beilstein J. Nanotechnol. 2020, 11, 1157–1167, doi:10.3762/bjnano.11.100

• by sinusoidally modulating the bias voltage (5 mVrms, 750 Hz) and measuring the first harmonic of the current response of the tunneling barrier. Results and Discussion Pt(111)–C42H28 Figure 2a shows an overview STM image of C42H28 on Pt(111) at a coverage of approx. 20%. Well separated molecules or

• states. The presented data were normalized by taking the exponential transmission factor of the tunneling barrier into account [38]. The normalized dI/dV data show a peak at approx. 2.3 V. Due to the considerably broad onset of dI/dV data starting from approx. 1 V it is difficult to unambiguously assign

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

• inefficient methodology of use, and inconsistent results [94]. The potential toxicity could be put to a good use, though. Hybrid Fe3O4/Gd2O3 loaded with cisplatin and tagged with lactoferrin and RGD (a cell endocytosis small peptide) was proved in vitro and in vivo to cross the blood–brain barrier and target