Recent progress in actuation technologies of micro/nanorobots

• Ke Xu and
• Bing Liu

Beilstein J. Nanotechnol. 2021, 12, 756–765, doi:10.3762/bjnano.12.59

• microelectrodes in water and solutions of high ionic strength. When the ultrasonic frequency is tuned to generate a vertical standing wave, the metal rod is suspended in the midpoint plane of a cylindrical cell. A rapid axial movement of 200 μm/s of the metal microprobe at the resonance frequency was observed

• dual-mode fluorescence and magnetic resonance imaging. Using magnetic targeting, the micro/nanorobot broke through complex physiological barriers and entered tumors while carrying a photosensitizer. After that, local high temperature was generated by a near-infrared laser, and observable and accurate

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

• [50] also proposed a navigation method for two-dimensional robust magnetic resonance of microrobots using ferromagnetic nanoparticles. Laurent Arcese et al. [51] discussed the control design of an intravascular magnetically guided microrobotic system for performing minimally invasive medical

• materials to propel and rotate microrobots. The force was proportional to the magnetic field gradient and had nothing to do with the induced current, so the resonance frequency could be used. The magnetic material designed by Kim’s team did not rely on the Lorentz force, avoiding the influence of the

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

• implementing light scattering (dynamic and electrophoretic) techniques, spectroscopy (UV–vis, atomic absorption, nuclear magnetic resonance) and transmission electron microscopy. The obtained results demonstrated that AgNPs may transform very quickly during their journey through different biological conditions

• absorption spectroscopy (GF-AAS), nuclear magnetic resonance (NMR) spectroscopy, and transmission electron microscopy (TEM) experiments. Physicochemical characteristics of freshly prepared AgNPs Freshly prepared AgNPs coated with PVP, sodium bis(2-ethylhexyl)sulfosuccinate (AOT), and poly(ʟ-lysine) (PLL

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

• /GaAs single quantum well structures were patterned with sets of stripes to emulate a grating structure, using doses of less than 1012 ions/cm2. The result was a periodic spatial modulation of the excitonic resonance of the quantum well perpendicular to the buried quantum well layer. Since the doses

High-yield synthesis of silver nanowires for transparent conducting PET films

• Gul Naz,
• Hafsa Asghar,
• Muhammad Ramzan,
• Muhammad Arshad,
• Rashid Ahmed,
• Muhammad Bilal Tahir,
• Bakhtiar Ul Haq,
• Nadeem Baig and
• Junaid Jalil

Beilstein J. Nanotechnol. 2021, 12, 624–632, doi:10.3762/bjnano.12.51

• electrical conductivity [12]. AgNWs are important as they offer a possibility to overcome light–matter interaction in the visible region. The optical properties of AgNWs are determined by localized surface plasmon resonance (LSPR), which depends on shape, size, and environment of the material [13]. AgNWs

• second peak at 373 nm is attributed to the longitudinal plasmon resonance of AgNWs. It is also noted that no other peak was observed, which shows that the final product was free from contamination of any other nanostructures, such as silver nanoparticles or nanocubes. The SEM results also confirm the

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

• supporting points is not straightforward. Consequently, we cannot calculate the absolute value of strain; however, its qualitative description is still possible. The 2D band has a complex line shape due to the double resonance signal [40][41]. Therefore, the graphene strain could be qualitatively examined by

Local stiffness and work function variations of hexagonal boron nitride on Cu(111)

• Abhishek Grewal,
• Yuqi Wang,
• Matthias Münks,
• Klaus Kern and
• Markus Ternes

Beilstein J. Nanotechnol. 2021, 12, 559–565, doi:10.3762/bjnano.12.46

• based on a shift of the field emission resonance (FER) induced by Φ variations. The effective potential well of depth Φ at the surface of a metal can accommodate a series of Rydberg states, extending a few angstroms into the vacuum above the metal surface [43]. These image potential states (IPSs

• , independent method to detect the variation in Φ. For this we record the frequency shift, Δf, of the resonance frequency of the cantilever oscillating perpendicular to the surface as a function of the bias voltage (see Figure 3b). At the extrema of the parabolic Δf curves, the electrostatic force is minimised

Influence of electrospray deposition on C₆₀ molecular assemblies

• Antoine Hinaut,
• Sebastian Scherb,
• Sara Freund,
• Zhao Liu,
• Thilo Glatzel and
• Ernst Meyer

Beilstein J. Nanotechnol. 2021, 12, 552–558, doi:10.3762/bjnano.12.45

• were obtained. Room-temperature AFM Room-temperature nc-AFM measurements were performed with a custom-built non-contact atomic force microscope with Nanonis electronics RC5. PPP-NCL cantilevers (Nanosensor) were used as sensor (typical resonance frequency of f1 = 170 kHz, oscillation amplitude A1 = 2–5

On the stability of microwave-fabricated SERS substrates – chemical and morphological considerations

• Limin Wang,
• Aisha Adebola Womiloju,
• Christiane Höppener,
• Ulrich S. Schubert and
• Stephanie Hoeppener

Beilstein J. Nanotechnol. 2021, 12, 541–551, doi:10.3762/bjnano.12.44

• laser excitation was set to 532 nm which overlaps with the plasmon resonance of the SERS substrates [24]. After an incubation time of eight minutes, the intensity of the characteristic peak of 4-ATP located at 1442 cm−1 reached a maximum intensity which did not further increase after longer incubation

Determining amplitude and tilt of a lateral force microscopy sensor

• Oliver Gretz,
• Alfred J. Weymouth,
• Thomas Holzmann,
• Korbinian Pürckhauer and
• Franz J. Giessibl

Beilstein J. Nanotechnol. 2021, 12, 517–524, doi:10.3762/bjnano.12.42

• related to the sensor parameters and the weighted average of the force gradient over the tip oscillation, ⟨kts⟩(x0, z0), where x0 and z0 define the average tip position over one oscillation cycle [14]: Here, f0 is the resonance frequency of the sensor away from the surface and k is the stiffness of the

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

• Paulina Filipczak Krzysztof Halagan Jacek Ulanski Marcin Kozanecki Department of Molecular Physics, Faculty of Chemistry, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland 10.3762/bjnano.12.40 Abstract The resonance Raman effect (RRE) is a phenomenon which results in a strong

• ; plasmons; resonance Raman effect; surface-enhanced Raman scattering; water structure; Introduction What is the structure of water? This question is among the 125 most important unanswered questions of mankind and it was proposed by the prestigious Science Magazine [1]. Water is the most common compound in

• stretching vibration band related to structured water depends also on the excitation wavelength, due to the resonance Raman effect. The first report of this phenomenon was presented by Pastorczak et al. [20]. It was shown that the 3200 cm−1 band is in resonance with the light in the red range of the spectrum

Rapid controlled synthesis of gold–platinum nanorods with excellent photothermal properties under 808 nm excitation

• Jialin Wang,
• Qianqian Duan,
• Min Yang,
• Boye Zhang,
• Li Guo,
• Pengcui Li,
• Wendong Zhang and
• Shengbo Sang

Beilstein J. Nanotechnol. 2021, 12, 462–472, doi:10.3762/bjnano.12.37

• conversion efficiency (PCE) due to local surface plasmon resonance (LSPR). Studies on different gold–platinum (Au–Pt) bimetal nanoparticles exhibiting the LSPR effect have provided a new idea for the synthesis of excellent PTAs. But there is no simple and scalable method for the controllable synthesis of Au

• . Keywords: AuNRs; local surface plasmon resonance (LSPR); photothermal conversion efficiency; photothermal transduction agents; platinum; Introduction On the surface of noble metal nanoparticles, when the wavelength of incident light resonates with the light absorption wavelength of the nanoparticles, a

A review on nanostructured silver as a basic ingredient in medicine: physicochemical parameters and characterization

• Gabriel M. Misirli,
• Kishore Sridharan and
• Shirley M. P. Abrantes

Beilstein J. Nanotechnol. 2021, 12, 440–461, doi:10.3762/bjnano.12.36

• AgNPs with light leads to surface plasmon resonance (SPR) effect when the incident light frequency coincides with the frequency of the oscillating electrons on the surface. The surface of AgNPs stores the conducting electrons inside the particles and establishes a restorative force which creates a

• blood tests, urinalysis, sputum induction, and magnetic resonance imaging of the chest and abdomen. After oral exposure, the silver content in the serum and urine was analyzed and no clinically abnormal changes were noted in the lungs, heart, or abdominal organs. Also, no morphological changes were

• –NIR absorption spectroscopy: Metallic nanoparticles are known to emit characteristic colors in the visible region of the electromagnetic spectrum due to a phenomenon known as surface plasmon resonance. The color of a colloidal nanoparticle solution is mainly dependent on the size and shape of the

Reconstruction of a 2D layer of KBr on Ir(111) and electromechanical alteration by graphene

• Zhao Liu,
• Antoine Hinaut,
• Stefan Peeters,
• Sebastian Scherb,
• Ernst Meyer,
• Maria Clelia Righi and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2021, 12, 432–439, doi:10.3762/bjnano.12.35

• a constant amplitude and controlled by the frequency shift. Bimodal AFM was used to combine the first flexural resonance (frequency of f1 ≈ 165 kHz, amplitude of A1 = 2–8 nm and a typical quality factor of Q1 = 30,000) or the second flexural resonance (frequency of f2 ≈ 1 MHz, amplitude of A2 = 200

• –800 pm and a typical quality factor of Q2 = 10,000) with the torsional resonance detection (frequency of ft ≈ 1.5 MHz, amplitude of At = 20–80 pm and a typical quality factor of Qt = 100,000) [50][52]. Kelvin probe force microscopy (KPFM) was performed in FM-KPFM mode by applying a DC compensation 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

Intracranial recording in patients with aphasia using nanomaterial-based flexible electronics: promises and challenges

• Qingchun Wang and
• Wai Ting Siok

Beilstein J. Nanotechnol. 2021, 12, 330–342, doi:10.3762/bjnano.12.27

• processing. This review presents findings on aphasia, an impairment in language and communication, and discusses how different brain imaging techniques, including positron emission tomography, magnetic resonance imaging, and iEEG, have advanced our understanding of the neural networks underlying language and

• neuroimaging methods such as positron emission tomography (PET), magnetic resonance imaging (MRI), functional magnetic resonance imaging (fMRI), diffusion tensor imaging (DTI), electroencephalography (EEG), magnetoencephalography (MEG), and intracranial electroencephalography (iEEG). Each of these methods has

The patterning toolbox FIB-o-mat: Exploiting the full potential of focused helium ions for nanofabrication

• Victor Deinhart,
• Lisa-Marie Kern,
• Jan N. Kirchhof,
• Sabrina Juergensen,
• Joris Sturm,
• Enno Krauss,
• Thorsten Feichtner,
• Sviatoslav Kovalchuk,
• Michael Schneider,
• Dieter Engel,
• Bastian Pfau,
• Bert Hecht,
• Kirill I. Bolotin,
• Stephanie Reich and
• Katja Höflich

Beilstein J. Nanotechnol. 2021, 12, 304–318, doi:10.3762/bjnano.12.25

• region exhibits temperatures around 800 K while the bridges stay close to room temperature. The resonance frequency of the fundamental mode is 12.5 MHz (cf. Figure 6b) and exhibits a quality factor of about 300 without laser heating. When suspended graphene is heated by a light source, the built-in

• tension in the device is reduced because graphene has a negative thermal expansion coefficient [53], and a down-shift in resonance frequency is observed. The mode frequency can be shifted up by 100 percent through increasing the laser power from 15 to 150 μW. The large bandwidth in combination with the

• resonance is significantly broadened for the lithographically defined tetramer. Interestingly, the highest Q factor (Q = ωres/δω with the resonance frequency Q = ωres and the resonance width δω) was achieved for the tetramers obtained by pure Ga patterning, even though the monomer shape is not perfectly

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

• -dispersion. A CTAB bilayer remained non-covalently bound onto the GNRs surface to maintain the stability of the final product. The longitudinal localized plasmon resonance (LSPR) and the transverse plasmon resonance (TSPR) of the prepared GNRs were found to be 780 and 526 nm, respectively. TEM images display

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

• ; Introduction Magnetic iron oxide nanoparticles (MNPs) as chemically inert material have been increasingly employed as contrast agents in magnetic resonance imaging (MRI), positron emission tomography (PET), and near-infrared fluorescence (NIRF) imaging [1]. The superparamagnetic properties of MNPs make them

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

Mapping the local dielectric constant of a biological nanostructured system

• Wescley Walison Valeriano,
• Rodrigo Ribeiro Andrade,
• Juan Pablo Vasco,
• Angelo Malachias,
• Bernardo Ruegger Almeida Neves,
• Paulo Sergio Soares Guimarães and
• Wagner Nunes Rodrigues

Beilstein J. Nanotechnol. 2021, 12, 139–150, doi:10.3762/bjnano.12.11

• oscillate, during the second pass, at the resonance frequency of the cantilever, f0. Variations in the local relative permittivity properties of the sample will lead to different tip–sample force gradients, which promote a shift Δf0 in the tip oscillation frequency [21][22] which is, approximately, where dF

• h is directly determined via AFM imaging. The microscope control software also determines the resonance frequency f0 and the elastic constant K of the cantilever using the thermal tune method [30][31]. A critical parameter is the tip–sample distance z, that consists of the height Hlift plus the

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

• resonance (SPR) and generally have a broad absorption spectrum [83]. This enables applications in optoelectronics and surface-enhanced Raman scattering [84][85]. AgNPs were also applied effectively in solar cell matrices [32][86][87]. AgNPs can enhance the current density in solar cells due to their far

• -field effect and localized surface plasmon resonance (LSPR) [32]. There are several applications in which use of 1D silver nanostructures such as nanowires (NWs) and nanorods (NRs) (at the same concentration) are preferred to other nanostructures due to stronger conductivity. For instance, 1D silver

Numerical analysis of vibration modes of a qPlus sensor with a long tip

• Kebei Chen,
• Zhenghui Liu,
• Yuchen Xie,
• Chunyu Zhang,
• Gengzhao Xu,
• Wentao Song and
• Ke Xu

Beilstein J. Nanotechnol. 2021, 12, 82–92, doi:10.3762/bjnano.12.7

• a diameter of 0.025 mm tip are shown in Figure 4. The grey dashed lines denote ftf. When the tip length is 0.5 mm, fq of the in-phase mode is very close to the dashed line (Figure 4a), which means that the tuning fork vibrates in resonance. When fq moves away from the dashed line and gets closer to

• ftip, the vibration of the qPlus sensor is mainly dominated by the tip, while the tuning fork hardly oscillates. The value of fq of the anti-phase mode is close to that of ftip for a 0.5 mm long tip (Figure 4b), resulting in tip resonance. As the tip length increases, fq gradually approaches ftf

• , leading to resonance of the tuning fork. If the tip length continues to increase, fq will be closer to the second-order ftip. The superposition vibration characteristics of the qPlus sensor are reflected in the amplitudes of the tuning fork and the tip, which will be discussed later. Amplitude of the

The role of gold atom concentration in the formation of Cu–Au nanoparticles from the gas phase

• Yuri Ya. Gafner,
• Svetlana L. Gafner,
• Darya A. Ryzkova and
• Andrey V. Nomoev

Beilstein J. Nanotechnol. 2021, 12, 72–81, doi:10.3762/bjnano.12.6

• this case, the energy and resonance line width depend on the percentage of copper. A Cu–Au nanoalloy is often produced using standard chemical methods. However, nanoparticles synthesized by these methods usually vary greatly in size, in the percentage of chemical elements, or in the structure formed

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

• range, <10 nm), and chemical forces (short range, <2 nm). By keeping the system in equilibrium (avoiding a snap onto the sample surface) the attractive forces at the surfaces are mapped, recording the change of resonance frequency due to the interacting attractive forces [23]. This method has not only

• ), according to: Bodies made from the same material show the highest attraction to each other, since the emitting field and the absorption by the oscillating dipoles are in resonance. Dissimilar materials attract each other less, which might even lead to repulsion. The attraction between two dissimilar

• nm. For high-resolution force spectroscopy an additional device was used in the AFM setup, an ImAFM (Intermodulation Products AB, Segersta, Sweden). The AFM probe used in this case was tip E (HQ: NSC35, Mikromasch, Wetzlar, Germany) with a resonance frequency f0 = 190 kHz, a spring constant kc = 12 N