A photonic crystal material for the online detection of nonpolar hydrocarbon vapors

• Evgenii S. Bolshakov,
• Aleksander V. Ivanov,
• Andrei A. Kozlov,
• Anton S. Aksenov,
• Elena V. Isanbaeva,
• Sergei E. Kushnir,
• Aleksei D. Yapryntsev,
• Aleksander E. Baranchikov and
• Yury A. Zolotov

Beilstein J. Nanotechnol. 2022, 13, 127–136, doi:10.3762/bjnano.13.9

• [14]. Most of the configuration changes of the photonic bandgap in opal and inverse opal structures occur due to swelling or compression of the polymer matrix or gel. To date, four main methods for the modification of photonic crystals are used for the creation of stimuli-responsive materials: (a

• ) formation of a sensitive polymer matrix, (b) impregnation of the reagent, (c) immobilization of the reagent and (d) preparation of the sensor elements from molecularly imprinted polymers. Organic solvents are usually detected by using polymer matrix sensors (Table 1) through matrix interaction [7][8][9][15

• into the polymer matrix (Figure 5). The effect of n-decane vapor does not lead to a significant change in the sensor color, but only shifts the PBG by just ≈10 nm, nevertheless, the approach proposed here allows one to detect slight changes in the sensor color. Aromatic and aliphatic hydrocarbons were

Tin dioxide nanomaterial-based photocatalysts for nitrogen oxide oxidation: a review

• Viet Van Pham,
• Hong-Huy Tran,
• Thao Kim Truong and
• Thi Minh Cao

Beilstein J. Nanotechnol. 2022, 13, 96–113, doi:10.3762/bjnano.13.7

• new insights into the underlying mechanism of heterojunction photocatalysts, especially those with Z-shaped interfaces [76]. Polyaniline (PANI) is a conducting polymer and compared to g-C3N4, PANI is inexpensive and easy to synthesize. Bui et al. [35] presented a SnO2/PANI nanocomposite for

• photocatalytic mechanisms, and the polymer photodegradation of the resulting nanocomposite using DFT techniques. The results confirmed that the interaction between NO and PANI is indeed a hydrogen bond and photogenerated holes serve as the primary factor of the photocatalytic NO removal [35]. Moreover, this

Theranostic potential of self-luminescent branched polyethyleneimine-coated superparamagnetic iron oxide nanoparticles

• Rouhollah Khodadust,
• Ozlem Unal and
• Havva Yagci Acar

Beilstein J. Nanotechnol. 2022, 13, 82–95, doi:10.3762/bjnano.13.6

• luminescent polymer. Therefore, it is usually tagged with an organic fluorophore to be optically tracked. Recently, we developed branched PEI (bPEI) superparamagnetic iron oxide nanoparticles (SPION@bPEI) with blue luminescence 1200 times stronger than that of bPEI without a traditional fluorophore, due to

• recently due to a very weak luminescence. Lin et al. synthesized mostly linear PEI and demonstrated a siRNA delivery with this luminescent polymer [27]. Sun et al. utilized the luminescence of branched PEI as the imaging modality in polymeric quantum dots (PDOTs) formed from amphiphilic polyethyleneimine

• in many in vitro studies including, for example, flow cytometry or fluorescence imaging, since the luminescence of the polymer was not detected [18][33][34]. Unfortunately, the luminescence of the fluorophores (dye or quantum dots) that are active in the visible range is usually significantly reduced

Nanoscale friction and wear of a polymer coated with graphene

• Robin Vacher and
• Astrid S. de Wijn

Beilstein J. Nanotechnol. 2022, 13, 63–73, doi:10.3762/bjnano.13.4

• challenging problem due to the complex viscoelastic properties and structure. Using molecular dynamics simulations, we investigate how a graphene sheet on top of the semicrystalline polymer polyvinyl alcohol affects the friction and wear. Our setup is meant to resemble an AFM experiment with a silicon tip. We

• have used two different graphene sheets, namely an unstrained, flat sheet, and one that has been crumpled before being deposited on the polymer. The graphene protects the top layer of the polymer from wear and reduces the friction. The unstrained flat graphene is stiffer, and we find that it constrains

• the polymer chains and reduces the indentation depth. Keywords: friction; graphene; molecular dynamics; polymer; Introduction Graphene is a two dimensional material that has remarkable properties, both electronic [1][2] and mechanical [3][4]. Even before anything was known about graphene, the

Sputtering onto liquids: a critical review

• Anastasiya Sergievskaya,
• Adrien Chauvin and
• Stephanos Konstantinidis

Beilstein J. Nanotechnol. 2022, 13, 10–53, doi:10.3762/bjnano.13.2

Biocompatibility and cytotoxicity in vitro of surface-functionalized drug-loaded spinel ferrite nanoparticles

• Sadaf Mushtaq,
• Khuram Shahzad,
• Tariq Saeed,
• Anwar Ul-Hamid,
• Bilal Haider Abbasi,
• Nafees Ahmad,
• Waqas Khalid,
• Muhammad Atif,
• Zulqurnain Ali and
• Rashda Abbasi

Beilstein J. Nanotechnol. 2021, 12, 1339–1364, doi:10.3762/bjnano.12.99

• the polymer, thereby rapidly releasing the drug from NPs into the cytosol [36]. Functionalized MFe2O4 NPs cause cytotoxicity in vitro The sulforhodamine B (SRB) assay was performed using HepG2 and HT144 cells to screen the cytotoxic potential of functionalized MFe2O4 (M = Fe, Co, Ni, Zn) NPs. The

• controls. The efficient retention of polymer-functionalized NPs in cancer cells, with the help of the EPR effect and a leaky vasculature system (pore diameter = 100 nm–2 µm) [7], reduces their nonspecific biological interactions with plasma proteins, contributing to a higher bioavailability [37]. SRB

• ZS (Malvern Instruments, 69 UK) and the uniform size distribution by gel electrophoresis (GE BIORAD). Drug attachment and drug release analyses were performed by using UV–vis spectroscopy (Thermo Scientific Evo 220). Phase transfer, polymer coating, and purification of MFe2O4 (M = Fe, Co, Ni, Zn) NPs

Polarity in cuticular ridge development and insect attachment on leaf surfaces of Schismatoglottis calyptrata (Araceae)

• Venkata A. Surapaneni,
• Tobias Aust,
• Thomas Speck and
• Marc Thielen

Beilstein J. Nanotechnol. 2021, 12, 1326–1338, doi:10.3762/bjnano.12.98

• reducing the frictional forces experienced when they walk on the leaves and might also provide mechanical stability to the growing plant organs. Here, we have studied the development of cuticular ridges on adaxial leaf surfaces of the tropical Araceae Schismatoglottis calyptrata. We used polymer replicas

• study, we have used polymer replicas of the S. calyptrata leaf surfaces at various ontogenetic stages for morphometric analyses. Polymer replication of the leaf surfaces helps to avoid artifacts arising from leaf dehydration during time-consuming microscopical analyses, especially with regard to the

• factor enabling the efficient separation of plant material from the epoxy negative molds during polymer replication. The third level is characterized by aged and uniformly aligned low aspect ratio ridges in a labyrinth-type arrangement (at stages 4 and 5) in H. brasiliensis (Supporting Information File 1

Enhancement of the piezoelectric coefficient in PVDF-TrFe/CoFe₂O₄ nanocomposites through DC magnetic poling

• Marco Fortunato,
• Alessio Tamburrano,
• Maria Paola Bracciale,
• Maria Laura Santarelli and
• Maria Sabrina Sarto

Beilstein J. Nanotechnol. 2021, 12, 1262–1270, doi:10.3762/bjnano.12.93

• temperatures. This process, usually referred to as electrical poling, requires the deposition of contact electrodes on the sample surface and the use of high-voltage apparatus. In the present work, in order to overcome these constraints, we have produced, characterized, and studied a polymer nanocomposite

• constant and good piezoelectric properties suitable for the fabrication of flexible piezoelectric nanogenerators [1][2][3][4][5][6][7]. One of the most extensively investigated piezoelectric polymers is poly(vinylidene fluoride) (PVDF). This polymer has attracted a lot of interest due to its excellent

• is well known that PVDF is characterized by four main polymorph phases, namely α, β, γ, and δ [12]. Due to its high thermodynamic stability at room temperature the α phase is the predominant one. However, the α phase does not contribute to the piezoelectricity of the polymer, whereas the γ and δ

Electrical, electrochemical and structural studies of a chlorine-derived ionic liquid-based polymer gel electrolyte

• Ashish Gupta,
• Amrita Jain,
• Manju Kumari and
• Santosh K. Tripathi

Beilstein J. Nanotechnol. 2021, 12, 1252–1261, doi:10.3762/bjnano.12.92

• Technology, Shirgaon, Virar East, Maharastra, 401305, India Department of Physics, School of Physical Sciences, Mahatma Gandhi Central University, Bihar-845401, India 10.3762/bjnano.12.92 Abstract In the present article, an ionic liquid-based polymer gel electrolyte was synthesized by using poly(vinylidene

• fluoride-co-hexafluoropropylene) (PVdF-HFP) as a host polymer. The electrolyte films were synthesized by using the solution casting technique. The as-prepared films were free-standing and transparent with good dimensional stability. Optimized electrolyte films exhibit a maximum room-temperature ionic

• conductivity of σ = 8.9 × 10−3 S·cm−1. The temperature dependence of the prepared polymer gel electrolytes follows the thermally activated behavior of the Vogel–Tammann–Fulcher equation. The total ionic transference number was ≈0.91 with a wider electrochemical potential window of 4.0 V for the prepared

The effect of cobalt on morphology, structure, and ORR activity of electrospun carbon fibre mats in aqueous alkaline environments

• Markus Gehring,
• Tobias Kutsch,
• Osmane Camara,
• Alexandre Merlen,
• Hermann Tempel,
• Hans Kungl and
• Rüdiger-A. Eichel

Beilstein J. Nanotechnol. 2021, 12, 1173–1186, doi:10.3762/bjnano.12.87

• respective signal intensities of the XPS C 1s range of the fibres is considered as shown in Figure 6. As expected for an increasing graphitisation, the amount of graphitic carbon (sp2) increases with carbonisation temperature, while the amount of sp3 carbon, expected in more amorphous or polymer-like samples

Assessment of the optical and electrical properties of light-emitting diodes containing carbon-based nanostructures and plasmonic nanoparticles: a review

• Keshav Nagpal,
• Erwan Rauwel,
• Frédérique Ducroquet and
• Protima Rauwel

Beilstein J. Nanotechnol. 2021, 12, 1078–1092, doi:10.3762/bjnano.12.80

• a uniform thin film. Some of the commonly used polymers and metal oxides for ETL are PBD, PBD-PMMA, BND, ZnO, SnO2, and TiO2 [69][70][71]. Improvements in the device performance have been reported, when using polymer–MWNT nanocomposite-based ETL. For example, Fournet et al. have investigated the

• (Figure 7) present the best results in terms of luminance and EL emission. In addition, the electron conductivity of the device is increased by four orders of magnitude. Concerning graphene–polymer nanocomposites, Choudhary et al. have inserted MoS2 and graphene oxide NP into a polyaniline ETL [72]. The

• , the device with 2–3% Ag-doped ZnO EIL shows maximum luminance of 10982 cd/m2, maximum current efficiency of 41.0 cd/A, and EQE of 15.2%. The addition of AgNP to PBD-based ETL enhances the green emission [75]. Kandulna et al. have addressed the effect of plasmonic NP on hybrid metal oxide–polymer

Use of nanosystems to improve the anticancer effects of curcumin

• Andrea M. Araya-Sibaja,
• Norma J. Salazar-López,
• Krissia Wilhelm Romero,
• José R. Vega-Baudrit,
• J. Abraham Domínguez-Avila,
• Carlos A. Velázquez Contreras,
• Ramón E. Robles-Zepeda,
• Mirtha Navarro-Hoyos and
• Gustavo A. González-Aguilar

Beilstein J. Nanotechnol. 2021, 12, 1047–1062, doi:10.3762/bjnano.12.78

• is distributed within a polymeric matrix (i.e., surrounded by the polymer) they are referred to as nanocapsules. Alternatively, if the drug is homogeneously dispersed in the polymeric matrix they are called nanospheres [78][79]. Their main advantages include their reactivity, surface area, stability

• min), which was associated with the ammonium groups present in the salts of the polymer material. Previous studies have reported that 90% of CUR at pH 7.4 degrades in 30 min [85], so the system developed by Umerska et al. [84] would increase its residence time. Polymeric nanoparticles sensitive to pH

• ± 12.25 nm, EE% 78.04 ± 0.54 >70% CUR). This was associated with the compatibility of the compound with the lipid medium and the presence of the surfactant in the polymer formulation (which has been reported to affect the % EE). In addition, they reported better cellular uptake of SLN, which was

An overview of microneedle applications, materials, and fabrication methods

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

Beilstein J. Nanotechnol. 2021, 12, 1034–1046, doi:10.3762/bjnano.12.77

• on hydrogel-forming polymer microneedles [16][17][18]. Microneedle patch technology has the potential to overcome the challenges involved in mass vaccination against COVID-19 across the world and has already shown promising achievements in delivering lyophilised or liquid formulation-based vaccines

• and released as the microneedles dissolve [34][37]. The main limitation of dissolvable microneedles is the limited choice of drugs that can be encapsulated into dissolvable polymer or polymer–sugar combinations [34][36], and the short time and low volume of drug delivery. Dissolvable polymer

• methods, notably DRIE. Drawing lithography has been used for high aspect ratio microneedles of heights 1600, 1200, and 600 μm [80][81]. This technique involves spin coating of a viscoelastic thermosetting polymer such as SU-8 epoxy resin, followed by thermal curing and controlled drawing of the material

Progress and innovation of nanostructured sulfur cathodes and metal-free anodes for room-temperature Na–S batteries

• Marina Tabuyo-Martínez,
• Bernd Wicklein and
• Pilar Aranda

Beilstein J. Nanotechnol. 2021, 12, 995–1020, doi:10.3762/bjnano.12.75

• cathode is reported to display a capacity of 153 mAh·g−1 after 500 cycles at 1C [39], while the latter has 257 mAh·g−1 after 200 cycles at 1C [40]. This problem is a consequence of the low sulfur content of the polymer, which is usually less than 50 wt % and the limited redox reactivity of sulfur [38][41

• instance, the development of polymer electrolytes, additives, salts, or specific materials that can be used in the preparation of components and conformation of elements of the battery. The analysis of the patent search results clearly shows a lack of specific patents dealing with the production of cathode

Self-assembly of Eucalyptus gunnii wax tubules and pure ß-diketone on HOPG and glass

• Miriam Anna Huth,
• Axel Huth and
• Kerstin Koch

Beilstein J. Nanotechnol. 2021, 12, 939–949, doi:10.3762/bjnano.12.70

• interface, covers all aerial non-lignified parts of higher plants [1]. It is an extracellular membrane of epidermal cells, consisting of a matrix of the polymer cutin and a mixture of hydrophobic compounds, the cuticular waxes [2][3]. This interface is a multifunctional surface optimized by evolution to

The role of deep eutectic solvents and carrageenan in synthesizing biocompatible anisotropic metal nanoparticles

• Nabojit Das,
• Akash Kumar and
• Raja Gopal Rayavarapu

Beilstein J. Nanotechnol. 2021, 12, 924–938, doi:10.3762/bjnano.12.69

• synthesis methods have been developed for environmental applications, such as biohydrogen production and chromium deionization [15][16][17][18]. In addition, polymer-based nanoparticles showed low drug loading and encapsulation efficiency. The acidic nature of poly(lactic-co-glycolic acid) is not suitable

• for certain drugs and bioactive molecules and make the polymer prone to a higher enzymatic degradation rate [19]. This is why there is a need for novel synthetic routes for synthesizing safe plasmonic metal nanoparticles maintaining high yield and monodispersity with tunable size and morphology

• application. The following section of the review focuses on DESs and carrageenan, a class of emerging green solvents and a carbohydrate polymer for synthesizing safe plasmonic nanomaterials. Deep eutectic solvents in nanotechnology The preparation of DESs involves mixing solid organic precursors with high

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