Gold nanomakura: nanoarchitectonics and their photothermal response in association with carrageenan hydrogels

• Nabojit Das,
• Vikas,
• Akash Kumar,
• Sanjeev Soni and
• Raja Gopal Rayavarapu

Beilstein J. Nanotechnol. 2024, 15, 678–693, doi:10.3762/bjnano.15.56

• gold nanomakura within a 600–700 nm wavelength. The aspect ratio as well as anisotropy of synthesized gold nanomakura can influence photothermal response upon near-infrared irradiation. The role of carbon tail length was evident via absorption peaks obtained from longitudinal surface plasmon resonance

• . Plasmon resonance in spherical nanoparticles can be stretched over a relatively small wavelength range by changing the diameter, whereas casting anisotropy serves an extra degree of freedom for controlling the plasmon band over a range of visible to infrared (IR) spectrum [4]. Gold nanoparticles are well

• -known noble metal materials whose resonance occurs in both visible and infrared range of the electromagnetic spectrum, rendering pertinence in various disciplines such as surface-enhanced Raman scattering (SERS), optical sensors, fluorescence (SPR) sensor chips, deoxyribonucleic acid (DNA) sensors

AFM-IR investigation of thin PECVD SiO_x films on a polypropylene substrate in the surface-sensitive mode

• Hendrik Müller,
• Hartmut Stadler,
• Teresa de los Arcos,
• Adrian Keller and
• Guido Grundmeier

Beilstein J. Nanotechnol. 2024, 15, 603–611, doi:10.3762/bjnano.15.51

• than 10–30 nm below the top surface). As this is a higher-order nonlinear effect, the resulting tip–surface force is very small compared to that of classical contact-mode-based AFM-IR techniques, such as the ring-down method or resonance-enhanced AFM-IR, where the photothermal tip–sample force can be

• measured in a first-order detection scheme with or without additional resonance enhancement. However, it contains chemical information from a much larger depth (hundreds of nanometers to several micrometers). If the difference or sum of freely selectable laser pulse repetition frequency and mechanical

• modulation (i.e., drive frequency) in surface-sensitive AFM-IR mode equals a mechanical resonance of the tip–surface contact, sufficient IR signal enhancement can be obtained at this frequency (i.e., detection frequency). This is used to measure the IR signature of thin material sections close to the top

Stiffness calibration of qPlus sensors at low temperature through thermal noise measurements

• Laurent Nony,
• Sylvain Clair,
• Daniel Uehli,
• Aitziber Herrero,
• Jean-Marc Themlin,
• Andrea Campos,
• Franck Para,
• Alessandro Pioda and
• Christian Loppacher

Beilstein J. Nanotechnol. 2024, 15, 580–602, doi:10.3762/bjnano.15.50

• reported on artificial atoms formed by quantum corrals [9]. In nc-AFM, the probe, whose mechanical behavior may advantageously be compared to that of a one-dimensional simple harmonic oscillator (SHO) of resonance frequency f1 (flexural fundamental eigenmode) and stiffness k1, is sinusoidally excited at f1

• resonance frequency remains unchanged, f1. When the tip is in the range of attractive interatomic forces Fint(r), that is, for tip–surface separations r 1 nm, non-linear effects modify the oscillator dynamics, which shifts its resonance frequency down to lower values < f1. The resulting frequency shift Δf

• , which forms the tip. The tip is electrically connected to an electrode that collects the tunneling current if scanning tunneling experiments are to be performed along with nc-AFM experiments. The qPlus sensors feature a resonance frequency of f1 ≃ 25 kHz and a most commonly reported stiffness of 1800 N

Radiofrequency enhances drug release from responsive nanoflowers for hepatocellular carcinoma therapy

• Yanyan Wen,
• Ningning Song,
• Yueyou Peng,
• Weiwei Wu,
• Qixiong Lin,
• Minjie Cui,
• Rongrong Li,
• Qiufeng Yu,
• Sixue Wu,
• Yongkang Liang,
• Wei Tian and
• Yanfeng Meng

Beilstein J. Nanotechnol. 2024, 15, 569–579, doi:10.3762/bjnano.15.49

• significantly suppressed HCC cell proliferation. Moreover, CUR-Fe@MnO2 NFs were effective T1/T2 contrast agents for molecular magnetic resonance imaging due to the release of Mn2+ and Fe3O4 NCs. Keywords: curcumin; hepatocellular carcinoma; magnetic resonance imaging (MRI); radiofrequency (RF) hyperthermia

• (Fe3O4 NCs), – CUR layer, – and MnO2 (CUR-Fe@MnO2 NFs). These NFs carry CUR and Fe3O4 NCs, achieve sustained and concurrent drug release, and can be used for molecular magnetic resonance imaging (MRI). Moreover, we explored the ability of the NFs to release drugs and evaluated their cytotoxic effects

• live/dead staining. In vitro magnetic resonance imaging CUR-Fe@MnO2 NFs can release Mn2+ and Fe3O4 NCs. Mn2+ can shorten the T1 effect, and Fe3O4 NCs can shorten the T2 effect. In this study, CUR-Fe@MnO2 NFs at pH 5.0 + GSH + H2O2 were mixed with a 1% agarose solution to create solutions of different

Aero-ZnS prepared by physical vapor transport on three-dimensional networks of sacrificial ZnO microtetrapods

• Veaceslav Ursaki,
• Tudor Braniste,
• Victor Zalamai,
• Emil Rusu,
• Vladimir Ciobanu,
• Vadim Morari,
• Daniel Podgornii,
• Pier Carlo Ricci,
• Rainer Adelung and
• Ion Tiginyanu

Beilstein J. Nanotechnol. 2024, 15, 490–499, doi:10.3762/bjnano.15.44

• ) is in resonance with the exciton energy in zinc blende ZnS [35], and the conditions for RRS are satisfied [36], while the difference between the PL excitation laser line of 325 nm (3.814 eV) and the position of the 3.726 eV emission peak is nearly equal to the 2LO phonon energy (88 meV). The

• excitation since its photon quantum energy is in resonance with excitons in ZnS single crystals. The emission was analyzed in a quasi-backscattering geometry through a double SDL-1 spectrometer. The signal from a FEU-106 photomultiplier with SbKNaCs photocathode working in a photon counting mode was fed to a

Potential of a deep eutectic solvent in silver nanoparticle fabrication for antibiotic residue detection

• Le Hong Tho,
• Bui Xuan Khuyen,
• Ngoc Xuan Dat Mai and
• Nhu Hoa Thi Tran

Beilstein J. Nanotechnol. 2024, 15, 426–434, doi:10.3762/bjnano.15.38

• of plasmonic materials, which extensively respond to electromagnetic waves with proper wavelengths in terms of free electrons resonating to the incident waves [9][15]. This is the fundamental principle of surface plasmon resonance (SPR). Moreover, plasmons are easily controlled at the nanoscale

• through different sizes, shapes, and surface morphologies of nanoparticles [16]. At the contacts among adjacent nanoparticles, so-called “hot spots” form; here, electromagnetic fields are effectively enlarged, leading to localized surface plasmon resonance (LSPR) [1][17]. Crucial parts of SERS-based

Unveiling the nature of atomic defects in graphene on a metal surface

• Karl Rothe,
• Nicolas Néel and
• Jörg Kröger

Beilstein J. Nanotechnol. 2024, 15, 416–425, doi:10.3762/bjnano.15.37

• are indeed lacking the graphene atomic lattice structure in their interior. Spatially resolved spectroscopy of the differential conductance (dI/dV, I: tunneling current, V: bias voltage) and of the tuning fork resonance frequency change (Δf) further unravel marked differences between these two kinds

• . Constant-height scanning tunneling spectroscopy (STS) of dI/dV was performed by sinusoidally modulating (5 mVrms, 725 Hz) the dc bias voltage and measuring the first harmonic of the ac current response of the tunneling junction with a lock-in amplifier. For AFM data acquisition, resonance frequency changes

• of an oscillating piezoelectric tuning fork sensor [37][38] (resonance frequency: 30.5 kHz, quality factor: 45000, amplitude: 50 pm) were mapped at constant height for topographic images. The vertical force between tip and sample was extracted from distance-dependent measurements of the resonance

Classification and application of metal-based nanoantioxidants in medicine and healthcare

• Nguyen Nhat Nam,
• Nguyen Khoi Song Tran,
• Tan Tai Nguyen,
• Nguyen Ngoc Trai,
• Nguyen Phuong Thuy,
• Hoang Dang Khoa Do,
• Nhu Hoa Thi Tran and
• Kieu The Loan Trinh

Beilstein J. Nanotechnol. 2024, 15, 396–415, doi:10.3762/bjnano.15.36

• personalized and targeted treatments for sclerosis. Recently developed Fe3O4–CeO2 core–shell NPs have shown great potential as platforms for both the diagnosis and treatment of vascular disorders associated with ROS. This is attributed to their impressive magnetic resonance imaging (MRI) capabilities and

Modulated critical currents of spin-transfer torque-induced resistance changes in NiCu/Cu multilayered nanowires

• Mengqi Fu,
• Roman Hartmann,
• Julian Braun,
• Sergej Andreev,
• Torsten Pietsch and
• Elke Scheer

Beilstein J. Nanotechnol. 2024, 15, 360–366, doi:10.3762/bjnano.15.32

• ][13] and ferromagnetic resonance modes [14][15]. Meanwhile it has been shown that it might also lead to sequential flipping of different free layers, which, on the one hand, increases the complexity of the STT effects [16] and, on the other hand, expands its applications [5]. In this work, we present

Controllable physicochemical properties of WO_x thin films grown under glancing angle

• Rupam Mandal,
• Aparajita Mandal,
• Alapan Dutta,
• Rengasamy Sivakumar,
• Sanjeev Kumar Srivastava and
• Tapobrata Som

Beilstein J. Nanotechnol. 2024, 15, 350–359, doi:10.3762/bjnano.15.31

• measurements, a conductive tip (Ti/Pt coated) having a resonance frequency of approx. 70 kHz, a stiffness of approx. 2 N·m−1, and a radius of curvature of approx. 30 nm was used for KPFM measurements. To examine the uniformity in work function values of each film, different regions on the sample surface were

Determining by Raman spectroscopy the average thickness and N-layer-specific surface coverages of MoS₂ thin films with domains much smaller than the laser spot size

• Felipe Wasem Klein,
• Jean-Roch Huntzinger,
• Vincent Astié,
• Damien Voiry,
• Romain Parret,
• Houssine Makhlouf,
• Sandrine Juillaguet,
• Jean-Manuel Decams,
• Sylvie Contreras,
• Périne Landois,
• Ahmed-Azmi Zahab,
• Jean-Louis Sauvajol and
• Matthieu Paillet

Beilstein J. Nanotechnol. 2024, 15, 279–296, doi:10.3762/bjnano.15.26

• resonance conditions), other bands associated to different second-order processes are observed in the Raman spectra with a strong intensity, their frequencies, widths, and intensity depending on the excitation energy [36]. In addition, resonance conditions alter the symmetry selection rules of phonons of

• MoS2 [35]. Some of the second-order bands overlap with the A1g and E12g modes, complicating the exact determination of the parameters of these modes recorded under resonance conditions. Furthermore, since the MoS2 exciton characteristics (energy, width, and spectral weight) can be changed by several

• number of MoS2 layers, one must necessarily work under off-resonance conditions, that is, by using incident laser energy far from both exciton resonance energies. In this work, we chose to perform Raman experiments using 532 nm (2.33 eV) laser excitation, because this is sufficiently far from the energy

Vinorelbine-loaded multifunctional magnetic nanoparticles as anticancer drug delivery systems: synthesis, characterization, and in vitro release study

• Zeynep Özcan and
• Afife Binnaz Hazar Yoruç

Beilstein J. Nanotechnol. 2024, 15, 256–269, doi:10.3762/bjnano.15.24

• ., cancer, diabetes, and atherosclerosis), magnetic resonance imaging (MRI), targeted drug delivery, photothermal therapy, gene therapy, and molecular and cellular monitoring [15][16]. Photothermal therapy (PTT), a treatment in which nanostructures are used, induces drug release or damages tumor cells with

Design, fabrication, and characterization of kinetic-inductive force sensors for scanning probe applications

• August K. Roos,
• Ermes Scarano,
• Elisabet K. Arvidsson,
• Erik Holmgren and
• David B. Haviland

Beilstein J. Nanotechnol. 2024, 15, 242–255, doi:10.3762/bjnano.15.23

• the coupling to the transmission line used to measure the microwave resonance. A detailed description of our fabrication is presented, including information about the process parameters used for each layer. We also discuss the fabrication of sharp tips on the cantilever using focused electron beam

• -induced deposition of platinum. Finally, we present measurements that characterize the spread of mechanical resonant frequency, the temperature dependence of the microwave resonance, and the sensor’s operation as an electromechanical transducer of force. Keywords: atomic force microscopy; force sensing

• (KIMEC) sensors. A force sensor designed specifically for scanning probe microscopy must have a sharp tip that is readily positioned and scanned over a surface. We operate the sensor near a mechanical resonance with a high quality factor Q for enhanced responsivity to force. The mechanical resonator is a

Graphene removal by water-assisted focused electron-beam-induced etching – unveiling the dose and dwell time impact on the etch profile and topographical changes in SiO₂ substrates

• Aleksandra Szkudlarek,
• Jan M. Michalik,
• Inés Serrano-Esparza,
• Zdeněk Nováček,
• Veronika Novotná,
• Piotr Ozga,
• Czesław Kapusta and
• José María De Teresa

Beilstein J. Nanotechnol. 2024, 15, 190–198, doi:10.3762/bjnano.15.18

• 20 µm × 20 µm, and image resolution of 512 × 512 pixels. The resonance frequency of the particular AFM probe was 43 kHz. The acquired data were post-processed using the Gwyddion software from the Czech Metrology Institute. The ex situ measured AFM profiles of SiO2 substrate after the processing with

Nanocarrier systems loaded with IR780, iron oxide nanoparticles and chlorambucil for cancer theragnostics

• Phuong-Thao Dang-Luong,
• Hong-Phuc Nguyen,
• Loc Le-Tuan,
• Xuan-Thang Cao,
• Vy Tran-Anh and
• Hieu Vu Quang

Beilstein J. Nanotechnol. 2024, 15, 180–189, doi:10.3762/bjnano.15.17

• nanocarrier that can be loaded with the chemotherapeutic medication chlorambucil and magnetic resonance imaging agents (e.g., iron oxide nanoparticles and near-infrared fluorophore IR780) for theragnostics. Poly(lactic-co-glycolic acid) was combined with the aforementioned ingredients to generate poly(vinyl

• . Clinical use of superparamagnetic oxide nanoparticles (SPIONs) has been authorized [9]. SPIONs have been utilized in magnetic particle imaging (MPI), magnetic resonance imaging (MRI), computer tomography (CT), and additional imaging models [9][10][11]. SPIONs have been modified to be applicable to a

Ferromagnetic resonance spectra of linear magnetosome chains

• Elizaveta M. Gubanova and
• Nikolai A. Usov

Beilstein J. Nanotechnol. 2024, 15, 157–167, doi:10.3762/bjnano.15.15

• ferromagnetic resonance (FMR) spectra of oriented and non-oriented assemblies of linear magnetosome chains are calculated by solving the stochastic Landau–Lifshitz equation. The dependence of the shape of the FMR spectrum of a dilute assembly of chains on the particle diameter, the number of particles in a

• that of random clusters of interacting spherical magnetite nanoparticles. The shape of FMR spectra of both assemblies is shown to differ appreciably even at sufficiently large values of filling density of random clusters. Keywords: chains of magnetosomes; ferromagnetic resonance spectra; magnetite

• of magnetic nanoparticle assemblies are often characterized by measuring ferromagnetic resonance (FMR) spectra [14][15]. The analysis of FMR spectra makes it possible to determine the effective magnetic field in the sample under study, which depends on the particle saturation magnetization, the type

Enhanced feedback performance in off-resonance AFM modes through pulse train sampling

• Mustafa Kangül,
• Navid Asmari,
• Santiago H. Andany,
• Marcos Penedo and
• Georg E. Fantner

Beilstein J. Nanotechnol. 2024, 15, 134–143, doi:10.3762/bjnano.15.13

• at frequencies far away from the resonance frequency of the cantilever (off-resonance tapping (ORT) modes) can provide high-resolution imaging of a wide range of sample types, including biological samples, soft polymers, and hard materials. These modes offer precise and stable control of vertical

• rate and therefore enables higher scan rates while refining the mechanical property mapping. Keywords: atomic force microscopy (AFM); feedback control; off-resonance tapping (ORT); pulsed-force mode; Introduction Constant force mode, a widely used AFM imaging mode, utilizes a feedback controller that

• the application of this AFM method when gentle and non-damaging imaging is required, for instance on soft biological materials [1]. In order to make the instrument technique suitable for imaging fragile samples, several dynamic modes that rely on the resonance characteristics of the cantilever have

In situ optical sub-wavelength thickness control of porous anodic aluminum oxide

• Aleksandrs Dutovs,
• Raimonds Popļausks,
• Oskars Putāns,
• Vladislavs Perkanuks,
• Aušrinė Jurkevičiūtė,
• Tomas Tamulevičius,
• Uldis Malinovskis,
• Iryna Olyshevets,
• Donats Erts and
• Juris Prikulis

Beilstein J. Nanotechnol. 2024, 15, 126–133, doi:10.3762/bjnano.15.12

• zinc oxide nanorods embedded within the PAAO template [13]. Recently, it was demonstrated that the PAAO thickness tuning can increase the signal intensity and refractometric sensitivity of localized surface plasmon resonance (LSPR) sensors constructed using gold nanoparticles, which are deposited on

Josephson dynamics and Shapiro steps at high transmissions: current bias regime

• Artem V. Galaktionov and
• Andrei D. Zaikin

Beilstein J. Nanotechnol. 2024, 15, 51–56, doi:10.3762/bjnano.15.5

• known as Shapiro steps [1]. The presence of such steps is the result of a resonance between Josephson oscillations and the external microwave signal. In tunnel junctions, the primary resonance occurs under the condition ω = ωJ. In a more general case, the corresponding condition takes the form or

Dual-heterodyne Kelvin probe force microscopy

• Benjamin Grévin,
• Fatima Husainy,
• Dmitry Aldakov and
• Cyril Aumaître

Beilstein J. Nanotechnol. 2023, 14, 1068–1084, doi:10.3762/bjnano.14.88

• that the modulation frequency of the light source is set high enough, it becomes possible to “stabilize” the static bending in a steady state, and photothermal cantilever excitation can be avoided (by setting the optical modulation at a frequency that differs from the cantilever resonance eigenmodes

• reference signals. Dual-heterodyne KPFM (DHe-KPFM) dramatically enhances the sensitivity to “weak” (i.e., a few mV) surface photovoltage signals, thanks to the amplification by the second resonance mode. Time-resolved measurements can be performed in data-cube mode, by recording spectra of the SPV Fourier

• ] further improves this approach. The idea is to set the modulated bias angular frequency so that the first right sideband (ω0 + ωac) is “rejected” at the second mechanical resonance eigenmode (frequency ω1) of the cantilever. Implementing this modulation/demodulation scheme is nowadays greatly facilitated

Spatial mapping of photovoltage and light-induced displacement of on-chip coupled piezo/photodiodes by Kelvin probe force microscopy under modulated illumination

• Zeinab Eftekhari,
• Nasim Rezaei,
• Hidde Stokkel,
• Jian-Yao Zheng,
• Andrea Cerreta,
• Ilka Hermes,
• Minh Nguyen,
• Guus Rijnders and
• Rebecca Saive

Beilstein J. Nanotechnol. 2023, 14, 1059–1067, doi:10.3762/bjnano.14.87

• mechanical resonance frequency (f0) executed by the lock-in amplifier 1 and the generated topography signal is controlled by the Z feedback. A sinusoidal AC bias (VAC) with drive of 1 V and frequency (fAC) of 5 kHz is applied to the tip through lock-in 2, generating a signal with a frequency of f0 ± fAC near

• the cantilever resonance. Modulating the tip with VAC while the cantilever is oscillating near its resonance frequency leads to frequency mixing and intermodulation of the two frequencies (f0 ± fAC) [34]. The lock-in amplifiers 2 and 3 are fed with the vertical deflection signal of the cantilever to

• measure the sideband signals at f0 + fAC and f0 − fAC. Then, their average is used for the KPFM feedback to adjust the DC bias. If fAC is chosen to be small enough, such that the sideband peaks are close to f0, the amplitude of these peaks will be enhanced by the mechanical resonance of the cantilever

Exploring internal structures and properties of terpolymer fibers via real-space characterizations

• Michael R. Roenbeck and
• Kenneth E. Strawhecker

Beilstein J. Nanotechnol. 2023, 14, 1004–1017, doi:10.3762/bjnano.14.83

• , this distinction in fundamental chemistry has significant implications for the structures and properties of the resulting fibers. To date, structure–property characterizations of Technora® in the literature have primarily focused on (i) X-ray diffraction (XRD), (ii) nuclear magnetic resonance (NMR

• N/m (nominal), k = 12–21 N/m (measured)) were used for AFM scans. By simultaneously exciting the AFM cantilever to its first and second resonance (f1 = 160–190 kHz and f2 = 900–1150 kHz, Figure 1c) and applying two distinct control conditions (amplitude modulation (AM) and frequency modulation (FM

• resonance frequencies (f1 and f2). The response of the cantilever as it scans across the exposed internal fiber surface provides information about the local fiber internal morphology and mechanical response (stiffness and transverse elastic modulus (ET)). Fiber-wide Technora® AFM maps. (a) Topography map

Nanoarchitectonics of photothermal materials to enhance the sensitivity of lateral flow assays

• Elangovan Sarathkumar,
• Rajasekharan S. Anjana and
• Ramapurath S. Jayasree

Beilstein J. Nanotechnol. 2023, 14, 988–1003, doi:10.3762/bjnano.14.82

• assays (LFAs) are currently the most widely used point-of-care testing technique with remarkable advantages such as simple operation, rapid analysis, portability, and low cost. Traditionally, gold nanoparticles are employed as tracer element in LFAs due to their strong localised surface plasmon resonance

• , before being captured by immobilized biomolecules on a test line in the nitrocellulose membrane [6][7]. In conventional LFAs, most commonly gold nanoparticles and coloured cellulose nanobeads have been used as tracer elements because of strong light absorption and surface plasmon resonance, which yield

• nanoparticles are exposed to light of a specific wavelength, they undergo coherent oscillation of surface electrons, leading to the production of thermal energy and enhanced electromagnetic signals. This phenomenon is known as localized surface plasmon resonance (LSPR), which has been recognized as a reliable

Fragmentation of metal(II) bis(acetylacetonate) complexes induced by slow electrons

• Janina Kopyra and
• Hassan Abdoul-Carime

Beilstein J. Nanotechnol. 2023, 14, 980–987, doi:10.3762/bjnano.14.81

• trapped into a usually unfilled molecular valence orbital (i.e., shape resonance) [20]. Such a process usually arises typically at electron energies below 4 eV. The molecular orbitals into which the excess electron may be trapped are reported in [15][16][17][18][19] for the investigated organometallic

• . However, for molecules that contain metal atoms, this energy can be as low as 1.3–1.4 eV [17]. The formation of the [ML2]− anion via the core-excited resonance occurs in NiL2 and ZnL2 at around 5 and 8 eV, respectively (Figure 1). Such “high”-energy resonances are unusual; however, they have been observed

• 7.0% of the TNI decomposition. As the resonance energy provides information on the electron capture process, the branching ratio provides information on the dynamics of the decay channels of the TNI. Conclusion The interaction of low-energy electrons with metal(II) bis(acetylacetonate) complexes

Green SPIONs as a novel highly selective treatment for leishmaniasis: an in vitro study against Leishmania amazonensis intracellular amastigotes

• Brunno R. F. Verçoza,
• Robson R. Bernardo,
• Luiz Augusto S. de Oliveira and
• Juliany C. F. Rodrigues

Beilstein J. Nanotechnol. 2023, 14, 893–903, doi:10.3762/bjnano.14.73

• , the ability for magnetic manipulation, the possibility of being used in magnetic resonance imaging, and the ability to generate controlled heat non-invasively when exposed to an alternating magnetic field [7][8]. In 2019, our group published an article describing a low-cost green synthesis of SPIONs