Modification of a SERS-active Ag surface to promote adsorption of charged analytes: effect of Cu²⁺ ions

• Bahdan V. Ranishenka,
• Andrei Yu. Panarin,
• Irina A. Chelnokova,
• Sergei N. Terekhov,
• Peter Mojzes and
• Vadim V. Shmanai

Beilstein J. Nanotechnol. 2021, 12, 902–912, doi:10.3762/bjnano.12.67

• value below 10 nm. Taking into account the diameter of the NPs, we conclude that the major part of their surface would remain uncovered by the polymer layer in the plasmonic film on the SERS substrate. AFM images (Figure S3, Supporting Information File 1) confirm our conclusion. Topology map shows that

• the NPs are sticking out of the polymer layer. The adhesion image proves that the surface properties of the immobilized Ag NPs strongly differ from those on the glass substrate and that the polymer does not cover them. Weak citrate interaction with the Ag surface enables one to treat the NPs with

• polyhexamethylene guanidine (PHMG) were used as basic polymer modifiers to create positive charges on the Ag surface (Figure 7, numbers 1 and 2). Both of them were described as effective Ag NP stabilizers, which lead to NPs with positive zeta potential [7][19]. We found that treatment of the Ag NPs with those

The role of convolutional neural networks in scanning probe microscopy: a review

• Ido Azuri,
• Irit Rosenhek-Goldian,
• Neta Regev-Rudzki,
• Georg Fantner and
• Sidney R. Cohen

Beilstein J. Nanotechnol. 2021, 12, 878–901, doi:10.3762/bjnano.12.66

Comprehensive review on ultrasound-responsive theranostic nanomaterials: mechanisms, structures and medical applications

• Sepand Tehrani Fateh,
• Lida Moradi,
• Elmira Kohan,
• Michael R. Hamblin and
• Amin Shiralizadeh Dezfuli

Beilstein J. Nanotechnol. 2021, 12, 808–862, doi:10.3762/bjnano.12.64

• carrier. The imaging applications of these materials will also be discussed. These materials include nanocarrier formulations and nanostructured contrast agents, such as microbubbles (MBs), surfactant-based carriers (including micelles, NEs, and niosomes), polymer-based carriers (including gels

• , dendrimers, and capsules), lipid-based carriers (including liposomes and solid lipid NP), and non-polymer-based structures (including nanomachines, gold NPs, titanium, carbon, and silica nanostructures) along with some other novel NPs which can trigger drug release after US activation. A discussion on these

• ) gas-filled structures that are stabilized by a lipid, surfactant, protein, or polymer shell, whose stiffness or rigidity can affect the final outcome of the MBs upon exposure to US [71][72][73]. During the cavitation event, backscattered energy leads to the expanding and shrinking of the MBs, which

Silver nanoparticles nucleated in NaOH-treated halloysite: a potential antimicrobial material

• Yuri B. Matos,
• Rodrigo S. Romanus,
• Mattheus Torquato,
• Edgar H. de Souza,
• Rodrigo L. Villanova,
• Marlene Soares and
• Emilson R. Viana

Beilstein J. Nanotechnol. 2021, 12, 798–807, doi:10.3762/bjnano.12.63

• again at 37 °C for 24 h. The minimal inhibitory concentration was determined examining bacterial growth at each nanoparticle concentration. Dispersion of Ag/HNT-8 in a LDPE polymer matrix Ag/HNT-8 was also tested as an antimicrobial additive to LDPE and the biocide properties of the resulting composite

• chemically compatible with LDPE, a non-polar polymer matrix. This coating was performed suspending the to-be-coated sample in 10 mL of ethanol/dodecanethiol mixture (200:1, v/v) for 24 h, followed by filtering, washing with ethanol, and drying at 60 °C for 2 h. The coated sample was labelled Ag/HNT-8/DIO

• plates of 8 × 8 cm2 (95 MPa, 860 mm/s, 1 m double screw, 170 °C injection temperature, 90 °C mold temperature). Polymer plates doped with Ag/HNT-8 and Ag/HNT-8/DIO were characterized by SEM. LDPE plates without any additive were also prepared to be used as control in the antimicrobial test. Finally

Silver nanoparticles induce the cardiomyogenic differentiation of bone marrow derived mesenchymal stem cells via telomere length extension

• Khosro Adibkia,
• Ali Ehsani,
• Asma Jodaei,
• Ezzatollah Fathi,
• Raheleh Farahzadi and
• Mohammad Barzegar-Jalali

Beilstein J. Nanotechnol. 2021, 12, 786–797, doi:10.3762/bjnano.12.62

• aggregates [34]. Polymer coatings can be used to prevent the NPs from aggregating. In the present study, polyvinylpyrrolidone-coated Ag-NPs were used. Another important aspect of the behavior of Ag-NPs is the rate and degree of the dissolution of Ag-NPs, which depends on their surface functionalization

• , strongly slows down the dissolution [35]. In another study, Zook et al. investigated the dissolution in DMEM cell culture medium and reported the dissolution of different polymer-coated Ag-NPs. It was found that the dissolution was increased in cell culture media in comparison to inorganic salt solutions

Recent progress in magnetic applications for micro- and nanorobots

• Ke Xu,
• Shuang Xu and
• Fanan Wei

Beilstein J. Nanotechnol. 2021, 12, 744–755, doi:10.3762/bjnano.12.58

• field of medicine. Zhang et al. [32] used polymer-conjugated magnetic nanoparticles as a MNR to effectively carry nucleic acids in vitro. Their team developed a polyethylenimine-conjugated magnetic nanomaterial. While exhibiting long-term stability, this material can realize redox-activated and magnet

• . The nanoreactor was assembled in the presence of a target mRNA analyte and a magnetic field to form a biocompartment enclosed by the polymeric brush. Due to the polymer brush, MaBiDz exhibited excellent properties such as stability, specificity, and semi-permeability. It provides a suitable

• low-level radiation shielding sheet with diamagnetic nanoparticles and wanted to develop a medical radiation fiber shielding, which is harmless to the human body. The uniform dispersion of magnetic nanoparticles into a polymer resin can not only reduce the weight of the material, but also avoid harm

Fate and transformation of silver nanoparticles in different biological conditions

• Barbara Pem,
• Marija Ćurlin,
• Darija Domazet Jurašin,
• Valerije Vrček,
• Rinea Barbir,
• Vedran Micek,
• Raluca M. Fratila,
• Jesus M. de la Fuente and
• Ivana Vinković Vrček

Beilstein J. Nanotechnol. 2021, 12, 665–679, doi:10.3762/bjnano.12.53

• ]. However, PVP-AgNPs were weakly negatively charged, even though PVP is a neutral polymer. The reason behind this can be found in residual BH4− ions that became strongly attached to the surface during the synthetic process and could not be removed by purification. Despite the ζ potential of −24.3 ± 3.7 mV

A review of defect engineering, ion implantation, and nanofabrication using the helium ion microscope

• Frances I. Allen

Beilstein J. Nanotechnol. 2021, 12, 633–664, doi:10.3762/bjnano.12.52

• gas atoms in the polymer, allowing the gas to diffuse out rather than accumulate [91]. In fact, a study has used localized helium ion irradiation to locally shrink a polymer and thereby modify the height of metallic thin films supported on a polymer substrate [92]. This effect was attributed to ion

• -induced scission of the polymer chains and subsequent cross-linking and compaction, which can be understood in terms of the dominance of energy losses by electronic scattering in the case of light ions such as helium, compared with the nuclear scattering that dominates energy loss for heavier ions. Yet

Nanoporous and nonporous conjugated donor–acceptor polymer semiconductors for photocatalytic hydrogen production

• Zhao-Qi Sheng,
• Yu-Qin Xing,
• Yan Chen,
• Guang Zhang,
• Shi-Yong Liu and
• Long Chen

Beilstein J. Nanotechnol. 2021, 12, 607–623, doi:10.3762/bjnano.12.50

• units. The challenges and prospects associated with D–A polymer-based photocatalysts are described as well. Keywords: π-conjugated polymeric photocatalysts; donor–acceptor junctions; nanostructure semiconductors; photocatalytic hydrogen production; Introduction To date, fossil fuels still are the

• covalent organic frameworks (COFs) [34]. Notably, a record HER of up to 307 mmol·h−1·g−1 has been achieved with a pyrene–bithiophene-based porous polymer as the photocatalyst [35]. During PHP by water splitting, first, the photocatalyst is excited by photons, and photoexcited electrons hop into the lowest

• functional groups and geometries of the polymer framework, the influence of different factors on the photocatalytic activity can be systematically investigated and, consequently, the structure–performance relationships are unveiled. Herein, the donor and acceptor fragments in the polymer structures are

Stability and activity of platinum nanoparticles in the oxygen electroreduction reaction: is size or uniformity of primary importance?

• Kirill O. Paperzh,
• Anastasia A. Alekseenko,
• Vadim A. Volochaev,
• Ilya V. Pankov,
• Olga A. Safronenko and
• Vladimir E. Guterman

Beilstein J. Nanotechnol. 2021, 12, 593–606, doi:10.3762/bjnano.12.49

• friendliness, low operating temperature, and high adaptability of specific characteristics [1][2][3]. The key components of PEMFC membrane–electrode assemblies (MEA) are the proton-exchange polymer membrane and porous electrode layers, in which current-forming reactions of oxygen electroreduction (ORR) and

• suspension of Pt/C catalysts (i.e., "catalytic ink"), 900 μL of isopropyl alcohol and 100 μL of a 0.5% aqueous emulsion of Nafion® polymer were added to 6 mg of each sample. Then, the suspension was dispersed with ultrasound for 15 min. Under continuous stirring, an aliquot of “ink” of 6 μL in volume was

Properties of graphene deposited on GaN nanowires: influence of nanowire roughness, self-induced nanogating and defects

• Jakub Kierdaszuk,
• Piotr Kaźmierczak,
• Justyna Grzonka,
• Aleksandra Krajewska,
• Aleksandra Przewłoka,
• Wawrzyniec Kaszub,
• Zbigniew R. Zytkiewicz,
• Marta Sobanska,
• Maria Kamińska,
• Andrzej Wysmołek and
• Aneta Drabińska

Beilstein J. Nanotechnol. 2021, 12, 566–577, doi:10.3762/bjnano.12.47

• copper foil with methane gas as the precursor [31]. Next, graphene was transferred onto GaN NWs substrates. Due to low adhesive forces between graphene and corrugated substrates, the most common method to transfer graphene with the use of poly(methyl methacrylate) (PMMA) polymer could not be applied for

• the transfer onto NW substrates [31]. Therefore, we used stable orthogonal frames from polydimethylsiloxane (PDMS) polymer to stabilize the graphene during the transfer process [32]. The GaN NW substrates were fabricated by plasma-assisted molecular beam epitaxy (PAMBE) in N-rich conditions on (111

Simulation of gas sensing with a triboelectric nanogenerator

• Kaiqin Zhao,
• Hua Gan,
• Huan Li,
• Ziyu Liu and
• Zhiyuan Zhu

Beilstein J. Nanotechnol. 2021, 12, 507–516, doi:10.3762/bjnano.12.41

• can also be used as sensors [22]. TENGs, originally proposed by Prof. Zhongling Wang [23], are microgenerators that convert mechanical energy into electrical energy based on the triboelectric effect [24]. In most TENG simulations, a triboelectric polymer material is in direct contact with an electrode

Surface-enhanced Raman scattering of water in aqueous dispersions of silver nanoparticles

• Paulina Filipczak,
• Krzysztof Hałagan,
• Jacek Ulański and
• Marcin Kozanecki

Beilstein J. Nanotechnol. 2021, 12, 497–506, doi:10.3762/bjnano.12.40

• been previously observed for polymer chains [49][50], even when only excluded volume interactions were assumed. Previous works [38][39], as well as the performed simulations, support the finding presented herein in which silver nanoparticles are able to induce surface-enhanced Raman scattering of water

Boosting of photocatalytic hydrogen evolution via chlorine doping of polymeric carbon nitride

• Malgorzata Aleksandrzak,
• Michalina Kijaczko,
• Wojciech Kukulka,
• Daria Baranowska,
• Martyna Baca,
• Beata Zielinska and
• Ewa Mijowska

Beilstein J. Nanotechnol. 2021, 12, 473–484, doi:10.3762/bjnano.12.38

• semiconductor polymer, as a metal-free and visible-light-responsive photocatalyst, has attracted dramatically growing attention in the field of visible-light-induced hydrogen evolution reaction (HER). It is characterized by facile synthesis, easy functionalization, attractive electronic band structure, and

The impact of molecular tumor profiling on the design strategies for targeting myeloid leukemia and EGFR/CD44-positive solid tumors

• Nikola Geskovski,
• Nadica Matevska-Geshkovska,
• Simona Dimchevska Sazdovska,
• Marija Glavas Dodov,
• Kristina Mladenovska and
• Katerina Goracinova

Beilstein J. Nanotechnol. 2021, 12, 375–401, doi:10.3762/bjnano.12.31

• articles regarding the use of EGFR mAbs as a specific targeting motif for polymer NPs such as poly(lactic acid-co-lysine), poly(ethylene glycol-co-caprolactone), an poly(lactic acid-co-glycolic acid) NPs. All of them have shown

Nickel nanoparticle-decorated reduced graphene oxide/WO₃ nanocomposite – a promising candidate for gas sensing

• Ilka Simon,
• Alexandr Savitsky,
• Rolf Mülhaupt,
• Vladimir Pankov and
• Christoph Janiak

Beilstein J. Nanotechnol. 2021, 12, 343–353, doi:10.3762/bjnano.12.28

• –air environment containing 10 ppm NO2 increased 1.6-fold (from 17.6 to 27.6 kΩ, Figure 6 left). Figure 6 (right) shows a sensor response curve for a sample that is a composite layer of Ni@rGO in the conductive polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). This layer is

Doxorubicin-loaded gold nanorods: a multifunctional chemo-photothermal nanoplatform for cancer management

• Uzma Azeem Awan,
• Abida Raza,
• Shaukat Ali,
• Rida Fatima Saeed and
• Nosheen Akhtar

Beilstein J. Nanotechnol. 2021, 12, 295–303, doi:10.3762/bjnano.12.24

• hemoglobin in the supernatant of GNPs-RBCs mixture by monitoring absorbance intensity at 570 nm. The absence of a marked hemotoxicity of this sample is mainly related to the presence of the polymer. The GNR surface had no direct contact with the RBCs because it was completely passivated by the PSS coating

• prepared by simple wet chemistry. A polymer was electrostatically conjugated, which facilitates the loading of DOX and its phototriggered release inside cancer cells in acidic environment. A comparatively good photothermal transfer ability has been achieved at a very low power density of 1.5 W/cm2 of NIR

• deionized water. GNR solution was added drop-wise to 2 mL of PSS (2 mg/mL in 8 mM NaCl). For maximum adsorption, the solution was kept under stirring at room temperature for 2 h. Excess polymer (supernatant fraction) was removed by centrifugation (12,000g for 10 min). The PSS-stabilized GNRs were re

Characterization, bio-uptake and toxicity of polymer-coated silver nanoparticles and their interaction with human peripheral blood mononuclear cells

• Sahar Pourhoseini,
• Reilly T. Enos,
• Angela E. Murphy,
• Bo Cai and
• Jamie R. Lead

Beilstein J. Nanotechnol. 2021, 12, 282–294, doi:10.3762/bjnano.12.23

• ), which were shown to be silver by using EDX analysis (Supporting Information File 1, Figure S1e). Peaks of other elements (C, Cu, and O) in EDX analysis were observed due to grid material that was used for sample preparation. DLS estimates the hydrodynamic size of NPs, which includes the polymer and

• UV–vis were used to quantify recapping, which was successful [42][56]. A solution of PVP10 (Mw = 10000, Sigma-Aldrich) was added to the NP batch while stirring vigorously for one hour. PVP is a non-toxic polymer [60][61] used to sterically stabilize particles by strongly binding to the AgNP core [56

The nanomorphology of cell surfaces of adhered osteoblasts

• Christian Voelkner,
• Mirco Wendt,
• Regina Lange,
• Max Ulbrich,
• Martina Gruening,
• Susanne Staehlke,
• Barbara Nebe,
• Ingo Barke and
• Sylvia Speller

Beilstein J. Nanotechnol. 2021, 12, 242–256, doi:10.3762/bjnano.12.20

• have been observed for dendritic cells. It has been shown that these structures serve as catchers for T cells [31]. Ruffles have been described on osteoblasts upon exposure to parathyroid extract [32] and after internalization of polymer or metal particles [33], on fibroblastoid cells [29][34], on

• temperature (n = 3). Water contact angle values were calculated with the associated software (ADVANCE, V.1.7.2.1, Krüss, Hamburg, Germany) via Young's equation. Plasma polymer coating: The specimens were coated with a plasma-polymerized allylamine (PPAAm) nanolayer using a low-pressure plasma reactor (V55G

Determination of elastic moduli of elastic–plastic microspherical materials using nanoindentation simulation without mechanical polishing

• Hongzhou Li and
• Jialian Chen

Beilstein J. Nanotechnol. 2021, 12, 213–221, doi:10.3762/bjnano.12.17

• Hongzhou Li Jialian Chen College of Environmental Science and Engineering, Engineering Research Center of Polymer Resources Green Recycling of Ministry of Education, Fujian Normal University, Fuzhou 350007, China 10.3762/bjnano.12.17 Abstract When using the Oliver–Pharr method, the indented

• elastic modulus and yield stress of a microsphere, E/σy, was systematically varied between 10 and 1000 to cover the mechanical properties of the materials most commonly encountered in engineering. For example, an elastic–plastic material with E/σy = 70 and E/σy = 300 is fairly typical for a polymer and

Toward graphene textiles in wearable eye tracking systems for human–machine interaction

• Ata Jedari Golparvar and
• Murat Kaya Yapici

Beilstein J. Nanotechnol. 2021, 12, 180–189, doi:10.3762/bjnano.12.14

• nowadays, a lithium-ion/polymer battery with a rating of 3.7 V and 500 mAh was chosen to power the system. The battery charge management circuitry and DC–DC boost converter were based on a MCP73831 (Microchip, USA) and a TPS61090 (Texas Instruments, USA), respectively. To split the regulated 5 V, a rail

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

• and power density) is virtually important and it is the major figure of merit for energy harvesting. The electric output performance of P-TENGs for energy harvesting and functionalities and a comparison between P-TENGs and polymer-based TENGs are summarized in Table 1 and Table 2, respectively. Due to

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

• infections, and also inhibit the growth of bacterial biofilms [14][15][16]. AgNPs were also used in developing strong thermally conductive materials. They were used in polymer composites to increase thermal conductivity (K) [77][78] for cooling applications in electronic equipment. Furthermore, AgNPs have

Effect of different silica coatings on the toxicity of upconversion nanoparticles on RAW 264.7 macrophage cells

• Cynthia Kembuan,
• Helena Oliveira and
• Christina Graf

Beilstein J. Nanotechnol. 2021, 12, 35–48, doi:10.3762/bjnano.12.3

• nanoparticles in polymer shells decreases with incubation time due to the occurrence of proliferation and exocytosis [65]. Such effects can be related to the functionalization and size of the nanoparticles as well as to ion release, and modulate the toxicity of lanthanide-containing particles as a function of

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

• limitation. Among them, conjugation with poly(ethylene glycol) (PEG) is one of the most effective methods because PEG is highly hydrophilic and flexible [28][29]. Functionalization using a hydrophilic polymer with positively charged groups is another effective way to reduce opsonization by the RES and

• -COOH is a hydrophilic polymer that can graft firmly onto CNTs by non-covalent bonding. In contrast to covalent bonding methods, this non-covalent strategy is more facile and efficient, and will not affect the inherent optical properties of CNTs. The long hydrophilic chains of PEG and the amino groups