Bulk chemical composition contrast from attractive forces in AFM force spectroscopy

• Dorothee Silbernagl,
• Media Ghasem Zadeh Khorasani,
• Natalia Cano Murillo,
• Anna Maria Elert and
• Heinz Sturm

Beilstein J. Nanotechnol. 2021, 12, 58–71, doi:10.3762/bjnano.12.5

• tip (T)) interact in a medium (m) is defined by the difference in the dielectric responses. The Hamaker coefficient AHam can be derived from the relative differences of the dielectric constant εS(f), εT(f), and εm(f), summed up over all the frequencies at which the fluctuations can occur (UV–vis–IR

ZnO and MXenes as electrode materials for supercapacitor devices

• Ameen Uddin Ammar,
• Ipek Deniz Yildirim,
• Feray Bakan and
• Emre Erdem

Beilstein J. Nanotechnol. 2021, 12, 49–57, doi:10.3762/bjnano.12.4

• environment of the lattice atoms and defects. With the aid of advanced characterization techniques one may get valuable information on site symmetry, atomic bonding, and, in particular, on the bandgap energy of semiconductors. Raman, photoluminescence (PL), UV–vis, and electron paramagnetic resonance (EPR

• ]. Indeed, this emission has nothing to do with the defects. In semiconductors; one may obtain a hint about the value of Eg. For instance, for bulk ZnO, the emission due to the e–h recombination appears in the UV region around 380 nm, which corresponds to ca. 3.2 eV. Hence, this emission is also called near

• , one may at least separate the surface and core defects safely. There are other useful characterization techniques, such as UV–vis spectroscopy, with which one may correlate the size effects and defect concentrations with the change in Eg. This is sometimes called bandgap engineering or tuning of the

Bio-imaging with the helium-ion microscope: A review

• Matthias Schmidt,
• James M. Byrne and
• Ilari J. Maasilta

Beilstein J. Nanotechnol. 2021, 12, 1–23, doi:10.3762/bjnano.12.1

• from a material under electron bombardment. Ionoluminescence (IL) describes the equivalent phenomenon in HIM when free electrons in the sample are excited by the bombardment of the sample by helium ions and emit photons in the range from near-IR to near-UV [3][21][22][23]. IL spectra as well as the

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

• . The photoexcited electrons and the presence of holes result in the oxidization of organic dyes via a free-radical mechanism. However, TiO2 is a wide-bandgap semiconductor (3.0–3.3 eV), which can only absorb UV light and it easily undergoes electron–hole recombination [11]. To circumvent this problem

• . Therefore, in this study we report on the growth of mesoporous SiO2@NiPS and titania-coated mSiO2@NiPS (mSiO2@NiPS/TiO2) core–shell nanostructures using a simple deposition-precipitation method. Transmission electron microscopy (TEM), N2 physisorption analysis, diffuse reflectance UV–visible spectroscopy

• functionality of nanomaterials greatly influence their photoactivity. UV–vis diffuse reflectance spectroscopy is a useful technique for probing the optoelectronic properties, band structure and molecular energy levels of semiconductors. It gives relevant information on the optical activity of nanomaterials as

Nanocasting synthesis of BiFeO₃ nanoparticles with enhanced visible-light photocatalytic activity

• Thomas Cadenbach,
• Maria J. Benitez,
• A. Lucia Morales,
• Cesar Costa Vera,
• Luis Lascano,
• Francisco Quiroz,
• Alexis Debut and
• Karla Vizuete

Beilstein J. Nanotechnol. 2020, 11, 1822–1833, doi:10.3762/bjnano.11.164

• -fabricated metal carboxylates as metal precursors. To the best of our knowledge, the synthesized particles are the smallest BiFeO3 particles ever prepared by any method. The samples were characterized by X-ray powder diffraction, transmission electron microscopy and UV–vis diffuse reflectance spectroscopy

• analyze the BiFeO3 nanomaterial are powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and UV–visible reflectance spectroscopy. Furthermore, we investigated the photocatalytic efficiency of this nanomaterial under visible light in the degradation of rhodamine B (RhB) as a model

• electron microscope (TEM). Fourier-transform infrared (FTIR) spectra of the nanoscale materials were recorded using a Jasco FT IR-4700 spectrometer. Bandgap information was obtained using the spectra recorded in a Perkin Elmer UV–vis spectrometer with an integrating sphere. Spectra were suitably

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

• stored overnight at 4 °C. The different DOX-loaded formulations were centrifugated 3–5 times for separating unencapsulated drugs. The supernatant liquid was stored for measuring the absorbance at 480 nm by UV–vis spectroscopy according to the preestablished standard curve. The drug loading efficiency (LE

• , the same volume of fresh PBS was supplied in the release medium. The concentration of released DOX in all samples was determined by measuring the UV absorbance. The cumulative release rate of DOX was calculated and the measurements were repeated for three times, averaging the results. Cell viability

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

• the basis of a comparative study of the role of material-related factors in the FIB-induced surface patterning. PMMA and PC polymers are especially interesting for many reasons: PMMA is widely used as a positive resist for X-ray, deep UV [8], electron and ion-beam lithography [9]. Structural

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

• systematically analyzed. The self-powered PDs exhibit high responsivity (1200 mA/W), high detectivity (1013 Jones) and fast response (τr = 18 μs, τf = 25 μs) under UV illumination. High and stable short-circuit output currents at each wavelength from ultraviolet (UV) to near-infrared (NIR) demonstrates that the

• wide bandgap (3.2 eV), which absorbs UV light and can be easily prepared [11][12]. A pyroelectric potential will be generated in ZnO when the temperature changes upon illumination. The internal electric field can effectively drive the flow of electrons through an external circuit, yielding a short

• carefully investigated and systematically analyzed. Also, the impact of the periodic frequency of the illumination and the optical power density on the short-circuit current and performance of PDs is analyzed carefully. This self-powered PDs show a full-spectrum response range from UV (325 nm) to near

High-responsivity hybrid α-Ag₂S/Si photodetector prepared by pulsed laser ablation in liquid

• Raid A. Ismail,
• Hanan A. Rawdhan and
• Duha S. Ahmed

Beilstein J. Nanotechnol. 2020, 11, 1596–1607, doi:10.3762/bjnano.11.142

• (SEM), energy-dispersive X-ray spectroscopy (EDX), and UV–vis spectroscopy. The optical absorption decreased and the optical energy gap of α-Ag2S increased from 1.5 to 2 eV after the CTAB surfactant was added to the Tu solution. XRD studies revealed that the synthesized Ag2S NPs were polycrystalline

• the ablation process. The vessel was covered with a thin glass slide to prevent the vapor from reaching the laser focusing lens. The optical absorbance of the colloidal Ag2S NPs was measured by using a UV–vis double-beam spectrophotometer (Lambda 750, Perkin Elmer). The thiourea solution was used as

• observed at 125, 484 and 730 cm−1. Figure 5a shows the effect of adding CTAB on the UV–vis absorption spectrum of colloidal Ag2S NPs. The optical absorption was measured immediately after laser ablation. The addition of the cationic surfactant CTAB to the Tu solution led to a decrease in the optical

Walking energy harvesting and self-powered tracking system based on triboelectric nanogenerators

• Mingliang Yao,
• Guangzhong Xie,
• Qichen Gong and
• Yuanjie Su

Beilstein J. Nanotechnol. 2020, 11, 1590–1595, doi:10.3762/bjnano.11.141

• excellent performance, which can be used as motion [35][36][37] and temperature sensors [38][39], UV detectors [40], tactile sensors [41][42][43], sensors for healthcare [44][45][46][47], humidity sensors, and gas sensors [48][49][50][51], for example. In this work, a flexible undulated electrode-based

Cu₂O nanoparticles for the degradation of methyl parathion

• Juan Rizo,
• David Díaz,
• Benito Reyes-Trejo and
• M. Josefina Arellano-Jiménez

Beilstein J. Nanotechnol. 2020, 11, 1546–1555, doi:10.3762/bjnano.11.137

• through UV–vis absorption of 4-NPh. Likewise, it was shown that the surface basicity increases with decreasing nanoparticle size. The presence of CuCO3 on the surface of Cu2O, identified using X-ray photoelectron spectroscopy (XPS), passivates its surface and consequently diminishes the degradation of MP

• bacteria are used for the degradation of MP, whereas photocatalytic degradation needs photons in the form of UV light and chemical degradation utilizes chemical species, such as copper(I) oxide (Cu2O) NPs in this work. Cu2O is widely known for its photocatalytic activity [29][30][31][32][33]. However

• does not represent the concentration of NPs because they are made up of different amounts of Cu2O. When the reactions were over, the NPs were separated by centrifugation. This was done also before each UV–vis absorption and NMR measurement. Degradation of MP with bulk Cu2O was also tested, giving

Self-assembly and spectroscopic fingerprints of photoactive pyrenyl tectons on hBN/Cu(111)

• Domenik M. Zimmermann,
• Knud Seufert,
• Luka Ðorđević,
• Tobias Hoh,
• Sushobhan Joshi,
• Tomas Marangoni,
• Davide Bonifazi and
• Willi Auwärter

Beilstein J. Nanotechnol. 2020, 11, 1470–1483, doi:10.3762/bjnano.11.130

• characterizing a family of pyridin-4-ylethynyl-functionalized pyrene derivatives in different environments. UV–vis measurements in toluene solutions revealed absorption at wavelengths consistent with density functional theory (DFT) calculations, while emission experiments showed a high fluorescence quantum yield

• allows the determination of the electronic properties of the pyrene adsorbates by STM and STS", and the comparison with the gaps estimated by theoretical simulations in vacuum and by UV-vis spectroscopies in solution. Remarkably, the electronic states of the pyrene adsorbates near the Fermi level, probed

• . Furthermore, the agreement between the gas-phase calculations and STM data indicated that no charging occurred upon pyrene adsorption on hBN/Cu(111) [37]. To complement the on-surface investigations, we measured the optical gap by means of UV–vis spectroscopic characterization in solution (toluene) of 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

• NPs has been directed towards water disinfection, food packaging in addition to their known use as a UV filter to prevent skin cancer [114]. Lopez de Dicastillo et al. (2019) developed hollow TiO2 nanotubes and nanospheres with high antimicrobial activity through the combination of electrospinning and

Role of redox-active axial ligands of metal porphyrins adsorbed at solid–liquid interfaces in a liquid-STM setup

• Thomas Habets,
• Sylvia Speller and
• Johannes A. A. W. Elemans

Beilstein J. Nanotechnol. 2020, 11, 1264–1271, doi:10.3762/bjnano.11.110

• ascribed to the occurrence of redox reactions in which chloride is oxidized to chlorine and the Mn(III) center of the porphyrin moiety is reduced to Mn(II). The resulting Mn(II) porphyrin products were identified by UV–vis analysis of the liquid phase. For solutions of Mn(III) porphyrins with non-redox

• supernatant solution. To investigate changes in supernatant composition during the STM experiments, ex situ UV–vis spectroscopy measurements were carried out. UV–vis spectra of supernatant solutions from different experiments in the modified STM setup using MnTUPCl and MnTUPOAc are depicted in Figure 3. The

• unsealed test tube next to the STM setup for the same four days. All used concentrations were 1 × 10−4 M. The UV–vis spectra of the sample and reference solutions of MnTUPOAc (Figure 3b) are nearly identical, showing the characteristic strong Soret band at 481 nm and Q-bands at 604 and 640 nm. In contrast

3D superconducting hollow nanowires with tailored diameters grown by focused He⁺ beam direct writing

• Rosa Córdoba,
• Alfonso Ibarra,
• Dominique Mailly,
• Isabel Guillamón,
• Hermann Suderow and
• José María De Teresa

Beilstein J. Nanotechnol. 2020, 11, 1198–1206, doi:10.3762/bjnano.11.104

• -patterned Ti pads (150 nm in thickness) to prevent charge effects on the insulator layer (250 nm thick of SiO2) thermally grown on a silicon wafer [23]. These chips were fabricated following a routine recipe for UV optical lithography using a lift-off method. For the electron tomography and (HR)STEM

• Information File 120: Electron tomography_transversal section_hollow NW grown at 7 pA and 1.009 nC. Acknowledgements The authors highly acknowledge Rubén Valero for the UV lithography process. The microscopy works have been conducted in the “Laboratorio de Microscopías Avanzadas” at “Instituto de Nanociencia

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

• thermoelectrically cooled charge-coupled device (CCD) (Princeton Instruments PIXIS 100BR eXcelon/UV) [28][47][48]. The experimental setup is described in detail in [28]. The DRS signal is defined as: where R(E, 0) and R(E, d) are the reflectance spectra of the bare substrate and the DBP covered substrate

Gram-scale synthesis of splat-shaped Ag–TiO₂ nanocomposites for enhanced antimicrobial properties

• Mohammad Jaber,
• Asim Mushtaq,
• Kebiao Zhang,
• Jindan Wu,
• Dandan Luo,
• Zihan Yi,
• M. Zubair Iqbal and
• Xiangdong Kong

Beilstein J. Nanotechnol. 2020, 11, 1119–1125, doi:10.3762/bjnano.11.96

• obtain homogeneous Ag–TiO2 nanocomposites with a high yield. The prepared compounds were characterized by XRD, SEM, EDS, FTIR and UV–vis spectrophotometry. The cell viability upon exposure to the splat-shaped Ag–TiO2 nanocomposites was evaluated by using the Cell Counting Kit-8 assay. The antimicrobial

• spectroscopy (FTIR, Nicolet IS50) was used to measure the infrared spectra. To detect the absorption profile of the prepared samples, the UV–vis spectroscopy technique was used. In vitro cytotoxicity The Cell Counting Kit-8 (CCK-8) was purchased from Beyotime Biotechnology (Shanghai, China). Human colon

• bonds [9]. The UV spectra of the Ag–TiO2 nanocomposite and pure TiO2 NPs shows the optical properties of these materials (Figure 3b). The absorption wavelength corresponding to pure TiO2 and Ag–TiO2 nanocomposites was ≈300 nm and this value was in accordance with the reported literature [7]. The

Straightforward synthesis of gold nanoparticles by adding water to an engineered small dendrimer

• Sébastien Gottis,
• Régis Laurent,
• Vincent Collière and
• Anne-Marie Caminade

Beilstein J. Nanotechnol. 2020, 11, 1110–1118, doi:10.3762/bjnano.11.95

• reaction was rapidly observed at room temperature showing that this reagent is indeed able to reduce gold. However, the final solution was black and, therefore, there is no nanoparticle, as shown by UV–vis spectroscopy. Thus, the results suggest that the Girard’s T reagent is a stronger reductant than the

• gold atom to the sulfur atom and thus the electron-withdrawing power of the sulfur towards phosphorus decreases [42]. This is consistent with the decrease observed for the 2JPP coupling constant upon complexation (Table 1). Synthesis of gold nanoparticles and UV–vis characterization The dissolution of

• of gold nanoparticles 0.5 mL of water was added to 30 mg of the powdered dendrimer complex 4. The dissolution occurred promptly yielding a colloidal suspension that instantaneously became deep red. The gold nanoparticles were characterized using a PerkinElmer Lambda 35 UV–vis spectrometer (Waltham

Plant growth regulation by seed coating with films of alginate and auxin-intercalated layered double hydroxides

• Vander A. de Castro,
• Valber G. O. Duarte,
• Danúbia A. C. Nobre,
• Geraldo H. Silva,
• Vera R. L. Constantino,
• Frederico G. Pinto,
• Willian R. Macedo and
• Jairo Tronto

Beilstein J. Nanotechnol. 2020, 11, 1082–1091, doi:10.3762/bjnano.11.93

• in the UV–vis region (37.1%) and the Zn/Al molar ratio of 2, the following formula is proposed for the hybrid material: Zn2Al(OH)6](NAA)·3H2O (calculated: 37.1% of NAA; 10.8% of H2O). The morphology and porosity of LDHs can change depending on the synthesis method and also on the chemical

• of NAA in the LDH was determined by electronic absorption spectrophotometry in the UV–vis region using the maximum absorption (λmax) at 280 nm [15]. The ZnAl-CO3-LDH material was synthesized for comparison in the bioassays. The sample was prepared by co-precipitation at constant pH value, according

A few-layer graphene/chlorin e6 hybrid nanomaterial and its application in photodynamic therapy against Candida albicans

• Selene Acosta,
• Carlos Moreno-Aguilar,
• Dania Hernández-Sánchez,
• Beatriz Morales-Cruzado,
• Erick Sarmiento-Gomez,
• Carla Bittencourt,
• Luis Octavio Sánchez-Vargas and
• Mildred Quintana

Beilstein J. Nanotechnol. 2020, 11, 1054–1061, doi:10.3762/bjnano.11.90

• concentration of Ce6 in the FLG-Ce6 hybrid was calculated using UV–vis absorption spectroscopy. Ce6 presents an intense absorption band at 407 nm, corresponding to the Soret band. A Ce6 calibration curve at this wavelength is then produced. Then, in order to obtain a correct approximation of the real

• Ce6 and FLG. Red spheres represent the out-of-plane moieties responsible for the stabilization of the hybrid nanomaterial in water by the oxygen atoms. Figure 3a shows the characterization results from UV–vis spectroscopy experiments on FLG-Ce6 and Ce6. The absorption spectrum of FLG-Ce6 shows

• negatively affected, resulting in the interaction by H-bond formation. Thus, FLG and Ce6 interact by means of π–π stacking, Ce6–Ce6 transition dipole, hydrogen bond formation, hydrophobic, and electron-donor interactions [36]. The observed changes in the UV–vis spectrum of FLG- Ce6 corroborates the TEM

Highly sensitive detection of estradiol by a SERS sensor based on TiO₂ covered with gold nanoparticles

• Andrea Brognara,
• Ili F. Mohamad Ali Nasri,
• Beatrice R. Bricchi,
• Andrea Li Bassi,
• Caroline Gauchotte-Lindsay,
• Matteo Ghidelli and
• Nathalie Lidgi-Guigui

Beilstein J. Nanotechnol. 2020, 11, 1026–1035, doi:10.3762/bjnano.11.87

• as SERS substrate for the detection of rhodamine 6G and other organic molecules. They obtained stable and reproducible results with a detection limit down to 10 µM, while also showing high recyclability through cleaning via UV irradiation. However, a main drawback of these methodologies is the use of

• acquired using a UV–vis–NIR spectrophotometer (PerkinElmer Lambda 1050) with a 150 mm diameter integrating sphere in the range of 250–2000 nm, illuminating the sample from the glass substrate side. All acquired spectra were normalized with respect to the contribution of the glass substrate. The SERS

Gas-sensing features of nanostructured tellurium thin films

• Dumitru Tsiulyanu

Beilstein J. Nanotechnol. 2020, 11, 1010–1018, doi:10.3762/bjnano.11.85

• films; Introduction Tellurium (Te) is a multifunctional chemical element used for the development of many devices, such as diodes with high (106) rectification ratios, thin-film field-effect transistors, optical recording media, infrared and UV detectors, strain-sensitive devices and others (see [1][2

A 3D-polyphenylalanine network inside porous alumina: Synthesis and characterization of an inorganic–organic composite membrane

• Jonathan Stott and
• Jörg J. Schneider

Beilstein J. Nanotechnol. 2020, 11, 938–951, doi:10.3762/bjnano.11.78

• reversed-phase solid phase extraction applications [70][71][72]. As test the analyte we used the slightly water-soluble and UV–vis-detectable chloroanilic acid [73]. Chloroanilic acid was dissolved in deionized water and the solution was pumped through the porous composite membranes using a syringe pump

• . Subsequently, the concentration of chloroanilic acid in the collected solution was determined with UV–vis-spectroscopy. The amount of adsorbed chloroanilic acid was calculated from the absorbance of the analyte stock solution (see Figure 12). Unfunctionalized ALOX-membranes adsorb 16.7% of chloroanilic acid

• methanol followed by equilibration with 2 mL of deionized water with the same flow rate. The amount of adsorbed chloroanilic acid (analyte) was determined from the collected solution of the loading step by UV–vis spectroscopy at a wavelength of 331 nm [73]. The membranes were placed in a stainless-steel

Band tail state related photoluminescence and photoresponse of ZnMgO solid solution nanostructured films

• Vadim Morari,
• Aida Pantazi,
• Nicolai Curmei,
• Vitalie Postolache,
• Emil V. Rusu,
• Marius Enachescu,
• Ion M. Tiginyanu and
• Veaceslav V. Ursaki

Beilstein J. Nanotechnol. 2020, 11, 899–910, doi:10.3762/bjnano.11.75

• ; photoluminescence; photosensitivity; spin coating; thin films; ZnMgO semiconductor alloy; Introduction The ZnMgO solid solution system is of interest due to the possibility to tailor many important physical properties by varying their composition. This alloy system covers a wide ultraviolet (UV) spectral range

• between the direct bandgaps of 3.36 eV for ZnO and 7.8 eV for MgO at room temperature, making it very attractive for short-wavelength optical applications such as UV detectors [1][2][3][4][5] and light emitters [6][7][8][9]. Various techniques have been used for the preparation of ZnMgO films such as

• ][32]. A comparison of MSM photodetectors based on ZnMgO films prepared by spin coating and spray pyrolysis performed recently revealed that the sensitivity of the structures prepared by spin coating is higher as compared to those obtained by spray pyrolysis, while the photoresponse to UV irradiation

Transition from freestanding SnO₂ nanowires to laterally aligned nanowires with a simulation-based experimental design

• Jasmin-Clara Bürger,
• Sebastian Gutsch and
• Margit Zacharias

Beilstein J. Nanotechnol. 2020, 11, 843–853, doi:10.3762/bjnano.11.69

• methanol. After a rest duration of 10 min, the samples were cleaned with DI water and dried with nitrogen. The as-cleaned samples were dried in a desiccator and afterwards cleaned in a UV/ozone cleaning system to remove residual organics at the substrate surface. Growth and characterization of the