High–low Kelvin probe force spectroscopy for measuring the interface state density

• Ryo Izumi,
• Masato Miyazaki,
• Yan Jun Li and
• Yasuhiro Sugawara

Beilstein J. Nanotechnol. 2023, 14, 175–189, doi:10.3762/bjnano.14.18

• advantages, namely high sensitivity to the electrostatic force gradient, high detection sensitivity using a cantilever with a weak spring constant at the first resonance, ease of implementation in adding FM-AFM, and no need to enhance the bandwidth of the cantilever deflection sensor. FM-KPFM is used to

• concentrations of the n, p, and n+ regions are 1 × 1015 cm−3, 2 × 1016 cm−3, and 5 × 1019 cm−3, respectively. As a force sensor, a PtIr-coated conductive cantilever (NanoWorld: NCHPt) was used. The resonance frequency f0, force constant k, and Q of the PtIr-coated cantilever were 292.68 kHz, 42 N/m, and 8406

Intermodal coupling spectroscopy of mechanical modes in microcantilevers

• Ioan Ignat,
• Bernhard Schuster,
• Jonas Hafner,
• MinHee Kwon,
• Daniel Platz and
• Ulrich Schmid

Beilstein J. Nanotechnol. 2023, 14, 123–132, doi:10.3762/bjnano.14.13

• Ioan Ignat Bernhard Schuster Jonas Hafner MinHee Kwon Daniel Platz Ulrich Schmid Institute of Sensor and Actuator Systems, TU Wien, Gußhaustraße 27–29, 1040 Vienna, Austria 10.3762/bjnano.14.13 Abstract Atomic force microscopy (AFM) is highly regarded as a lens peering into the next discoveries

Observation of collective excitation of surface plasmon resonances in large Josephson junction arrays

• Roger Cattaneo,
• Mikhail A. Galin and
• Vladimir M. Krasnov

Beilstein J. Nanotechnol. 2022, 13, 1578–1588, doi:10.3762/bjnano.13.132

• consists of a log-periodic microwave antenna [39] with a broad frequency range of ca. 15–700 GHz. In the center, there is a nanoscale JJ sensor, shown in Figure 6b. The detector is made of a Nb film (70 nm thick), using a fabrication technique similar to that described in [28]. The antenna is patterned

• using photolithography and reactive ion etching. The JJ sensor with variable thickness and a width of ≈100 nm is made by Ga+ focused ion beam etching. The JJ is made small in order to increase its resistance Rn to approx. 50 Ω, which is needed for a good impedance matching with the antenna. In order to

• characteristics from (a). The peak represents the resonant step. It reduces with decreasing N and is not visible for N = 106 (lower panel) below the threshold number of JJs. (a) Optical image of a superconducting detector with a log-periodic microwave antenna. (b) SEM image of a nanoscale sensor junction (false

From a free electron gas to confined states: A mixed island of PTCDA and copper phthalocyanine on Ag(111)

• Alfred J. Weymouth,
• Emily Roche and
• Franz J. Giessibl

Beilstein J. Nanotechnol. 2022, 13, 1572–1577, doi:10.3762/bjnano.13.131

• of the sample preparation is available in Supporting Information File 1. A qPlus AFM/STM sensor [21] with an etched W-tip was used. Tunneling spectoscopy data (dI/dV data) were acquired with a lock-in amplifier included in the control electronics (Nanonis from SPECS GmbH). The AC signal had a

• frequency of 879 Hz, and we used a modulation voltage amplitude of 20 mV after ensuring that spectra did not change in shape with modulation voltages between 5 and 20 mV. The bias voltage and AC signal were applied to the sample. AFM data were acquired in frequency-modulation mode [22] with a sensor

• oscillation amplitude of 50 pm. The resonance frequency of the sensor is 38819 Hz, which is much higher than the modulation voltage used for spectroscopy data. Results and Discussion Figure 1a is an AFM image of an island showing both PC and P2C phases. The internal structure of the molecules appears similar

Frequency-dependent nanomechanical profiling for medical diagnosis

• Santiago D. Solares and
• Alexander X. Cartagena-Rivera

Beilstein J. Nanotechnol. 2022, 13, 1483–1489, doi:10.3762/bjnano.13.122

• mechanical sensor into an endoscopy pill, which would save or transmit its mechanical data to a computer for further analysis. Endoscopy capsules for optical imaging of the digestive tract already exist [30]. A schematic for a proposed enhancement to this type of device is shown in Figure 2. In addition to

• optical imaging, the device could be equipped with one or more piezoelectrically excited membranes coupled with a sensing mechanism, such as an AFM cantilever or other type of mechanical sensor (similar stand-alone developments already exist [31][32]). The mechanical response of the membrane could be

Rapid and sensitive detection of box turtles using an electrochemical DNA biosensor based on a gold/graphene nanocomposite

• Abu Hashem,
• M. A. Motalib Hossain,
• Ab Rahman Marlinda,
• Mohammad Al Mamun,
• Khanom Simarani and
• Mohd Rafie Johan

Beilstein J. Nanotechnol. 2022, 13, 1458–1472, doi:10.3762/bjnano.13.120

• hydrochloride (EDC) were used to covalently link DNA and oligonucleotides to a carboxylate-terminated alkanethiol self-assembled monolayer (SAM) performed on a gold electrode (AuE) [70]. The Lisdat group described a label-free impedimetric sensor for the detection of hybridisation events which is based on short

Double-layer symmetric gratings with bound states in the continuum for dual-band high-Q optical sensing

• Chaoying Shi,
• Jinhua Hu,
• Xiuhong Liu,
• Junfang Liang,
• Jijun Zhao,
• Haiyan Han and
• Qiaofen Zhu

Beilstein J. Nanotechnol. 2022, 13, 1408–1417, doi:10.3762/bjnano.13.116

• controlling the cavity length of the structure. Further, the two types of BIC can be converted into quasi-BIC (QBIC) by either changing the spacing between adjacent gratings or changing the distance between the upper and lower gratings. The simulation results show that the dual-band high-performance sensor is

• ]. Particularly, the QBIC sensor enables highly accurate detection of environmental changes by reading variations in the spectrum. However, numerous research works have focused on the BIC mechanism of single-mode resonance [26][28], which may limit its application. In this work, we proposed a double-layer

• index of the surrounding medium. In this section, we will investigate the sensing performance of the proposed structure through the variation of two key structural parameters (α and h). Besides the Q-factor, the sensitivity (S) and FOM are also two important parameters for a refractive index sensor

Dry under water: air retaining properties of large-scale elastomer foils covered with mushroom-shaped surface microstructures

• Matthias Mail,
• Stefan Walheim,
• Thomas Schimmel,
• Wilhelm Barthlott,
• Stanislav N. Gorb and
• Lars Heepe

Beilstein J. Nanotechnol. 2022, 13, 1370–1379, doi:10.3762/bjnano.13.113

• Effect, the capability to keep a stable air layer when submerged under water. Such air layers are of great importance, e.g., for drag reduction (passive air lubrication), antifouling, sensor applications or oil–water separation. Some biological models, e.g., the floating fern Salvinia or the backswimmer

Studies of probe tip materials by atomic force microscopy: a review

• Ke Xu and
• Yuzhe Liu

Beilstein J. Nanotechnol. 2022, 13, 1256–1267, doi:10.3762/bjnano.13.104

• , providing new opportunities for many fields. In practical applications, due to the surface structure of colloidal fibers, these fibers can be used as SERS sensor detection for trace detection of BPA. Although colloidal probes have many excellent properties, there are some problems in calibrating such probes

Design of surface nanostructures for chirality sensing based on quartz crystal microbalance

• Yinglin Ma,
• Xiangyun Xiao and
• Qingmin Ji

Beilstein J. Nanotechnol. 2022, 13, 1201–1219, doi:10.3762/bjnano.13.100

• sensing systems for enantiomers, which still remains challenging. Quartz crystal microbalance (QCM) is a well-known mass-sensor technique capable of recording changes in nanogram or even picogram levels in both gas and liquid phases [20][21]. The sensing of mass changes is based on the oscillation

• induced by external stimulus. As there are almost no limitations for the receptor layers in QCM sensor systems, various materials and nanostructures have been developed for constructing sensing layers on the surface of the electrode. The sensing process may also be implemented in the liquid and gas phases

• in the pharmaceutical industry. It has been taken as a model molecule to verify the “proof-of-principle” concept for chiral recognition [28]. Kim and co-workers fabricated ʟ-phenylalanine (ʟ-Phe)-modified QCM sensor and used vapor diffusion molecular assembly (VDMA) to study the chiral adsorption of

Application of nanoarchitectonics in moist-electric generation

• Jia-Cheng Feng and
• Hong Xia

Beilstein J. Nanotechnol. 2022, 13, 1185–1200, doi:10.3762/bjnano.13.99

• generate an electrical signal up to 10 mV and successfully applied it to a flow sensor. In 2008, Zhao et al. prepared a single-walled carbon nanotube generator [7], which imparted momentum to the water in the carbon nanotubes by applying a voltage to both ends of the carbon nanotubes, such that the other

• for green energy in the near future. MEGs are also widely used in sensors [54]. For example, a moisture-eletric touch sensor array can provide uniform and sensitive touch feedback (Figure 10e). As shown in Figure 10f, a breath detector can monitor different breathing patterns, including short breaths

• Clearance Center, Inc. This content is not subject to CC BY 4.0. (e) Touch sensor. (f) Breath detection sensor, different breathing modes yield different output voltages. Figure 10e,f were reproduced from [54], Shen, D. et al., “Self-Powered Wearable Electronics Based on Moisture Enabled Electricity

A cantilever-based, ultrahigh-vacuum, low-temperature scanning probe instrument for multidimensional scanning force microscopy

• Hao Liu,
• Zuned Ahmed,
• Sasa Vranjkovic,
• Manfred Parschau,
• Andrada-Oana Mandru and
• Hans J. Hug

Beilstein J. Nanotechnol. 2022, 13, 1120–1140, doi:10.3762/bjnano.13.95

• tuning fork force sensor became increasingly popular. In comparison to microfabricated cantilevers, the more macroscopic tuning forks, however, lack sensitivity, which limits the measurement bandwidth. Moreover, multimodal and multifrequency techniques, such as those available in cantilever-based AFM

• macroscopic wire tip to the free prong. Compared to the typically used microscopic AFM cantilevers, the tuning fork sensor has a rather high stiffness, k ≈ 2 kN/m. This facilitates AFM operation with small oscillation amplitudes (A < 100 pm) because a snap-to-contact or instabilities of the phase-locked loop

• (PLL) driving the tuning fork oscillation do not occur. Furthermore, the tuning fork AFM does not require an extra deflection sensor such as the beam deflection or fiber-optical systems used for cantilever-based AFM, which substantially reduces instrumentation complexity. In fact, every existing

Recent advances in green carbon dots (2015–2022): synthesis, metal ion sensing, and biological applications

• Aisha Kanwal,
• Naheed Bibi,
• Sajjad Hyder,
• Arif Muhammad,
• Hao Ren,
• Jiangtao Liu and
• Zhongli Lei

Beilstein J. Nanotechnol. 2022, 13, 1068–1107, doi:10.3762/bjnano.13.93

• dual fluorescence sensor for both Hg2+ ions and chemet drugs [23]. An acid oxidation approach was applied to synthesize nanosized fluorescent CDs of various colors by using Ananas comosus without any passivating agent by Gupta et al. The synthesized CDs showed three emission peaks at 438, 516, and 543

• as a dual sensor for tetracycline and ʟ-lysine. The fluorescence of CDs is quenched by adding tetracycline and regained by introducing ʟ-lysine [18]. Palmyra leaves were utilized by Athinarayanan et al. for the production of CDs. The cellular toxicity of the CDs was analyzed, and the CDs were found

• to synthesize CDs via hydrothermal route. The reported CDs showed good selectivity for Cd2+ ions with a wide linear range and limit of detection of 0.01–8 μM and 0.29 nM, respectively [72]. Chaudhary et al. reported CDs using roasted gram as a green precursor, which act as a humidity sensor. Two

Interaction between honeybee mandibles and propolis

• Leonie Saccardi,
• Franz Brümmer,
• Jonas Schiebl,
• Oliver Schwarz,
• Alexander Kovalev and
• Stanislav Gorb

Beilstein J. Nanotechnol. 2022, 13, 958–974, doi:10.3762/bjnano.13.84

• substrate material, a metal spring (springs with spring constants of 618 N/m and 539 N/m were used) and a fibre-optic sensor (Figure 3A). The piezo drive moves the spring down to load and up to unload the sample. A shortened glass capillary (5 µL micropipet Blaubrand® IntraEND, Brand GmbH & Co. KG, Wertheim

• . BM, bee mandible (optional); FL, fluid; FOS, fibre-optic sensor; GC, glass capillary; GS, glass slide or other substrate material; MM, micro-manipulators; MR, mirror; MS, metal spring; PS, propolis sample. Figure 3A was adapted and Figure 3B, D, and E were reproduced from [1] (© 2021 Saccardi

DNA aptamer selection and construction of an aptasensor based on graphene FETs for Zika virus NS1 protein detection

• Nathalie B. F. Almeida,
• Thiago A. S. L. Sousa,
• Viviane C. F. Santos,
• Camila M. S. Lacerda,
• Thais G. Silva,
• Rafaella F. Q. Grenfell,
• Flavio Plentz and
• Antero S. R. Andrade

Beilstein J. Nanotechnol. 2022, 13, 873–881, doi:10.3762/bjnano.13.78

• average behavior of this group of sensing devices with respect to protein addition. We evaluated the sensor responses as percentage changes in graphene resistance (ΔRSD) at VG = 0.2 V caused by aptamer–protein binding. For more details on how the variations in graphene resistances were measured, see Table

Numerical modeling of a multi-frequency receiving system based on an array of dipole antennas for LSPE-SWIPE

• Alexander V. Chiginev,
• Anton V. Blagodatkin,
• Dmitrii A. Pimanov,
• Ekaterina A. Matrozova,
• Anna V. Gordeeva,
• Andrey L. Pankratov and
• Leonid S. Kuzmin

Beilstein J. Nanotechnol. 2022, 13, 865–872, doi:10.3762/bjnano.13.77

• the working temperature of the 3He cryostat used for the LSPE project. One of main candidates for LSPE-SWIPE is a transition-edge sensor (TES) with a spiderweb antenna [2][3]. For the OLIMPO mission, kinetic inductance detectors (KIDs) were used [4]. We propose to use cold-electron bolometers (CEBs

Optimizing PMMA solutions to suppress contamination in the transfer of CVD graphene for batch production

• Chun-Da Liao,
• Andrea Capasso,
• Tiago Queirós,
• Telma Domingues,
• Fatima Cerqueira,
• Nicoleta Nicoara,
• Jérôme Borme,
• Paulo Freitas and
• Pedro Alpuim

Beilstein J. Nanotechnol. 2022, 13, 796–806, doi:10.3762/bjnano.13.70

• B2 mixture yields more consistent electric properties of the graphene channel, thanks to a homogenous and reproducible process. Such characteristics ultimately translate into a consistent sensor performance, which is pivotal for industrial fabrication. Conclusion Monolayer graphene films and single

A nonenzymatic reduced graphene oxide-based nanosensor for parathion

• Sarani Sen,
• Anurag Roy,
• Ambarish Sanyal and
• Parukuttyamma Sujatha Devi

Beilstein J. Nanotechnol. 2022, 13, 730–744, doi:10.3762/bjnano.13.65

• the fabrication of a robust, nonenzymatic electrochemical-sensing electrode modified with electrochemically reduced graphene oxide (ERGO) to detect PT residues in environmental samples (e.g., soil, water) as well as in vegetables and cereals. The ERGO sensor shows a significantly affected

• and straightforward responsive nature, high sensitivity, and selectivity leading to real-time detection [7]. A combination of a receptor, an analyte, and a transducer is made up to obtain an electrochemical sensor, in which the surface of the electrode induces redox characteristics via selective

Modeling a multiple-chain emeraldine gas sensor for NH₃ and NO₂ detection

• Hana Sustkova and
• Jan Voves

Beilstein J. Nanotechnol. 2022, 13, 721–729, doi:10.3762/bjnano.13.64

• numerically modeled for several adsorbed gas concentrations, several gas configurations, and different PANI molecule positions, including carrier hopping between them. The results are comparable to the experiment and show good properties for the application as gas sensor device for NH3 detection and rather

• good properties for NO2 detection. Keywords: ammonia; gas sensor; nitrogen dioxide; numerical computation; polyaniline; Introduction Polyaniline is a conducting polymer consisting of benzene rings connected by nitrogen units, which can be used in a wide spectrum of applications, for example, dyes for

• base has to be reduced by electrons (Figure 1). Emeraldine base or leucoemeraldine base salts of green color and with conductivity values of up to 400 S/m can be obtained through synthesis [4]. Recently, the polyaniline emeraldine salt has been studied for sensor applications for various gases because

Direct measurement of surface photovoltage by AC bias Kelvin probe force microscopy

• Masato Miyazaki,
• Yasuhiro Sugawara and
• Yan Jun Li

Beilstein J. Nanotechnol. 2022, 13, 712–720, doi:10.3762/bjnano.13.63

• was arranged in front of a photodetector of the OBD system to suppress the influence of the UV light on the deflection sensor. We used a commercial Ir-coated Si cantilever (NANOSENSORS, SD-T7L100) with a resonant frequency f0 of 913 kHz, a spring constant k of 650 N/m, and a quality factor Q of 7748

• density nFM is described as [74] where ntherm is the thermal noise density, ndetect is the detector noise density, nosc is the oscillator noise density, and nds is the deflection sensor noise density. The frequency noise δf measured with a bandwidth of B at a center of fm is described as When fm ≫ B, δf

Quantitative dynamic force microscopy with inclined tip oscillation

• Philipp Rahe,
• Daniel Heile,
• Reinhard Olbrich and
• Michael Reichling

Beilstein J. Nanotechnol. 2022, 13, 610–619, doi:10.3762/bjnano.13.53

• acquisition with an inclined tip sampling path requires modifications of the experimental procedures and data analysis protocols for force measurements to avoid systematic errors in the interpretation of force curve and imaging data. Results and Discussion Sensor positioning, sensor displacement, and tip

• be strictly parallel to Furthermore, we assume an infinitely stiff sensor in directions perpendicular to as well as a linear sensor response along Then, the static probe response follows Hooke’s law with k being the static sensor force constant [18]. In dynamic mode operation, the sensor is

• excited to periodic displacement q(t) = q(t + 1/fexc) along the q-axis at an excitation frequency fexc. To bring the tip in the desired range of interaction with the surface and to perform the movements required for imaging, force mapping, and taking force curves, the sensor is moved by coarse and fine

Detection and imaging of Hg(II) in vivo using glutathione-functionalized gold nanoparticles

• Gufeng Li,
• Shaoqing Li,
• Rui Wang,
• Min Yang,
• Lizhu Zhang,
• Yanli Zhang,
• Wenrong Yang and
• Hongbin Wang

Beilstein J. Nanotechnol. 2022, 13, 549–559, doi:10.3762/bjnano.13.46

• the fluorescent “ON” form. Keywords: cell imaging; fluorescence probes; glutathione; gold nanoparticles; mercury ions; rhodamine 6G derivatives; Introduction Metal nanoparticles have been widely used in the development and construction of sensor systems and drug carriers due to their excellent

Zinc oxide nanostructures for fluorescence and Raman signal enhancement: a review

• Ioana Marica,
• Fran Nekvapil,
• Maria Ștefan,
• Cosmin Farcău and
• Alexandra Falamaș

Beilstein J. Nanotechnol. 2022, 13, 472–490, doi:10.3762/bjnano.13.40

A non-enzymatic electrochemical hydrogen peroxide sensor based on copper oxide nanostructures

• Irena Mihailova,
• Vjaceslavs Gerbreders,
• Marina Krasovska,
• Eriks Sledevskis,
• Valdis Mizers,
• Andrejs Bulanovs and
• Andrejs Ogurcovs

Beilstein J. Nanotechnol. 2022, 13, 424–436, doi:10.3762/bjnano.13.35

• interfering substances, that is, ascorbic acid, uric acid, dopamine, NaCl, glucose, and acetaminophen, do not affect the electrochemical response. The real milk sample test showed a high recovery rate (more than 95%). According to the obtained results, this sensor is suitable for practical use for the

• qualitative detection of H2O2 in real samples, as well as for the quantitative determination of its concentration. Keywords: copper oxide; electrochemical sensor; hydrogen peroxide; nanostructures; Introduction Hydrogen peroxide, a strong oxidant and an essential intermediate product in many biomedical

• being horseradish peroxidase) [34][35][36], and detection is carried out through physicochemical processes of interaction between H2O2 and the enzyme. This type of sensor has high catalytic activity, sensitivity, and selectivity. However, enzyme sensors have a significant disadvantage, namely enzyme

A chemiresistive sensor array based on polyaniline nanocomposites and machine learning classification

• Jiri Kroutil,
• Alexandr Laposa,
• Ali Ahmad,
• Jan Voves,
• Vojtech Povolny,
• Ladislav Klimsa,
• Marina Davydova and
• Miroslav Husak

Beilstein J. Nanotechnol. 2022, 13, 411–423, doi:10.3762/bjnano.13.34

• 1999/2, 182 21 Prague, Czech Republic 10.3762/bjnano.13.34 Abstract The selective detection of ammonia (NH3), nitrogen dioxide (NO2), carbon oxides (CO2 and CO), acetone ((CH3)2CO), and toluene (C6H5CH3) is investigated by means of a gas sensor array based on polyaniline nanocomposites. The array

• data by principal component analysis to be a highly accurate method reach to 99% of the classification of six different gases. Keywords: feature extraction; gas sensor; pattern recognition; sensor array; Introduction The control and monitoring of toxic gaseous substances, such as ammonia, nitrogen

• . In most cases, the cross-sensitivity toward different chemical analytes is unavoidable, regardless of their oxidizing or reducing nature. Many authors have suggested a number of ways to overcome the drawbacks of cross-sensitivity/selectivity and reliability of the sensor arrays [3][4][5]. One