Molecular assemblies on surfaces: towards physical and electronic decoupling of organic molecules

• Sabine Maier and
• Meike Stöhr

Beilstein J. Nanotechnol. 2021, 12, 950–956, doi:10.3762/bjnano.12.71

• significant enhancement of the excited-state spin lifetimes [62]. Concerning optical properties, successful decoupling made the examination of fluorescence from both single molecules and molecular assemblies feasible by tunneling electron excitation [19][63][64][65][66]. Also, sub-molecularly resolved Raman

• otherwise only achieved for multilayers on the bare Ni. On hBN/Cu(111), Zimmermann et al. [87] could visualize the molecular orbitals of pyrene derivatives by STM at the submolecular level, while Brülke et al. [88] measured the fluorescence of monolayer perylenetetracarboxylic dianhydride (PTCDA), which is

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

• for bioconjugation [34]. Thus, oligonucleotide SERS spectra can indicate a positive charge of the SERS substrate surface. An oligonucleotide was labeled with a Black Hole Quencher dye (BHQ1) for better spectrum recognition due to exclusion of characteristic peaks with background fluorescence, which is

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

• image types was achieved, such as in images of cells and worms, enabling efficient cell-counting and viability prediction, as well as of silver nanowires. Image classification and segmentation CNNs are popular for cell classification. A CNN model based on actin-labeled fluorescence microscopy images

• continuous high-speed and blur-free bright-field and two-color fluorescence image acquisition of cells flowing at a rate of 1 m/s [106]. An outstanding CNN for image segmentation is U-Net, developed mainly for biomedical image segmentation [107]. It leads to precise and fast segmentation of images and

• , fluorescence microscopy, and serial block-face scanning electron microscopy (SBEM) micrographs [108]. Deep learning techniques have been developed for segmentation and tracing of neurons in volume electron microscopy for synaptic connectivity reconstruction. Mitochondria, synapses, axons, dendrites, spines

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

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

• and the fluorescent cells were visualized under a fluorescence microscope. Cell proliferation assay by MTT The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay measures the mitochondrial activity of the cells [45]. After the BM-MSCs grew to 70–80% confluence, they were washed

• (Corbett Research, Australia). Fluorescence data was calculated in relation to β-actin CT values by the 2−ΔΔCT method. Primers (Table 3) were designed using Oligo 7 v.7.52 software [44][48][49]. Protein expression assessment The proteins were extracted from cardiomyogenically differentiated BM-MSCs and

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

• 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

• sensor can approach F-sub, and then F-sub cutting and fluorescence signal amplification are carried out in the presence of analytes. Bakshi et al. proposed a cellular nanoreactor. It had two kinds of magnetic particles, each of which is functionalized by two components of the binary deoxyribozyme system

• developed an electromagnetic coil system (MagDisk) integrated into a fluorescence microscope and a fluorescent magnetic spore-based microrobot (FMSM). The MagDisk was low-cost and plug-and-play, and consisted of five independent coils. The maximum magnetic field strength of the MagDisk was around 20 mT. The

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

• . Conversely, helium ion irradiation of another material, silicon nitride, in the HIM was found to reduce its fluorescence [60]. This was attributed to ion beam-induced disruption of the optically active defects present in the material. In the cited work, the effect was used to locally reduce the fluorescence

• of patches of a silicon nitride membrane that were subsequently perforated by helium ion beam milling to create solid-state nanopores for biomolecule detection. Following this approach, a low fluorescence background was achieved, facilitating the translocation detection of fluorescently labeled

Boosting of photocatalytic hydrogen evolution via chlorine doping of polymeric carbon nitride

• Malgorzata Aleksandrzak,
• Michalina Kijaczko,
• Wojciech Kukulka,
• Daria Baranowska,
• Martyna Baca,
• Beata Zielinska and
• Ewa Mijowska

Beilstein J. Nanotechnol. 2021, 12, 473–484, doi:10.3762/bjnano.12.38

• ) radiation in a Prevac (Poland) system equipped with a Scienta SES 2002 (Sweden) electron energy analyzer operating with a constant transmission energy (Ep = 50 eV). The analysis chamber was evacuated to a pressure below 5 × 10−9 mbar. The PL spectra were measured using a fluorescence spectrophotometer

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

• properties such as significant absorption or scattering in the visible and near-infrared (NIR) regions, tunable aspect ratio, biocompatibility, fluorescence properties, and the ease of biofunctionalization, which makes them ideal in biomedical applications [13]. Gold-based nanomaterials (i.e., nanospheres

• fluorescence measurements (Biotek synergy H4 multi-mode plate reader) following the method reported in [23]. In vitro cytotoxicity assays The in vitro cytotoxicity of PSS-GNRs was measured using 3T3 and HepG2 cells. Cells were seeded in 96-well plates (4 × 103 cells per well) in 100 μL DMEM supplemented with

• DOX release at different pH values. Fluorescence intensity was measured from 0 to 30 h. (b) Heating curves of water, PSS GNRs and PSS-GNRs-DOX (10 µg Au/mL) under NIR (808 nm) laser irradiation. (a) Relative viabilities of HepG2 and 3T3 cells after being incubated with different concentrations of PSS

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

The nanomorphology of cell surfaces of adhered osteoblasts

• Christian Voelkner,
• Mirco Wendt,
• Regina Lange,
• Max Ulbrich,
• Martina Gruening,
• Susanne Staehlke,
• Barbara Nebe,
• Ingo Barke and
• Sylvia Speller

Beilstein J. Nanotechnol. 2021, 12, 242–256, doi:10.3762/bjnano.12.20

• fluorescence lifetime map of a membrane label is transferred into a gap distance map [48]. The cell is adhered to a transparent metal layer and gap distances of 67 ± 7 nm have been determined for fibroblast-like cells (A549). Interestingly, the gap varies by more than 40 nm along the adhesion interface and by

Fusion of purple membranes triggered by immobilization on carbon nanomembranes

• René Riedel,
• Natalie Frese,
• Fang Yang,
• Martin Wortmann,
• Raphael Dalpke,
• Daniel Rhinow,
• Norbert Hampp and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2021, 12, 93–101, doi:10.3762/bjnano.12.8

• the final linker is shown in Figure 2a. The functionalization was tested with the His-tagged fluorescent protein mTurqoise. Confirmation of successful functionalization was provided by fluorescence imaging as seen in Figure 2b. The images show that the complex bonds formed with His-labeled proteins

• CNM and a c-His PM. The c-His PM consists of BR (purple) with a lipid bilayer between the BR molecules. The chemical structure shows the linker used to build a complex between NTA CNM and c-His PM. (b) Fluorescence microscopy of NTA-functionalized NBPT CNMs incubated with a fluorescent protein

• fluorescence signal in I. indicates that the functionalization was successful. (c) XPS spectra of the NBPT SAM (green), NBPT CNM (blue), and NBPT CNM after the NTA functionalization (red). (d) IRRAS spectrum of NBPT CNM after the first functionalization step. (e) UV–vis absorption spectrum of a c-His PM

Effect of different silica coatings on the toxicity of upconversion nanoparticles on RAW 264.7 macrophage cells

• Cynthia Kembuan,
• Helena Oliveira and
• Christina Graf

Beilstein J. Nanotechnol. 2021, 12, 35–48, doi:10.3762/bjnano.12.3

• scattering setup, Prof. Dr. E. Rühl (Freie Universität Berlin) for providing access to the fluorescence spectrometer, and Dr. S. Berendts from the research group of Prof. Dr. M. Lerch (Technische Universität Berlin) for the XRD measurements. This work is primarily based on the doctoral dissertation of its

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

• holds promise to detect fluorescent biomarkers with better resolution than that achievable even with the most advanced super-resolution optical microscopy techniques, for instance, stimulated emission depletion microscopy [51]. In particular, it may allow for correlating fluorescence microscopy with HIM

• that coating, as required for SEM, introduces artefacts such as a granular structure on the cell surfaces and a partial closing of pores, thus highlighting one of the benefits of HIM. Bazou et al. also studied tumour cell-induced platelet aggregation by fluorescence microscopy and HIM. In this study

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

• antitumor activity. Furthermore, fluorescence detection and flow cytometry (FCM) analysis results indicated that the internalization into cells of CNTs-PEG-PEI was significantly enhanced, thus inducing tumor cell death through apoptosis more efficiently. The above series of benefits of CNTs-PEG-PEI may be

• wells, and the cells were trypsinized with trypsin–EDTA and washed with cold PBS for three times to remove the nanocarriers outside the cells. The cells were then collected and resuspended in 200 μL of PBS by centrifugation. The mean fluorescence intensity (MFI) was determined using FCM (BD Biosciences

• , SanJose), with 488 nm wavelength excitation and 590 nm wavelength emission, and untreated cells were used as blank. Fluorescence observation of the cellular internalization was also conducted. In brief, cells were seeded into 24-well plates, after complete attachment, fresh serum-free medium containing

Cardiomyocyte uptake mechanism of a hydroxyapatite nanoparticle mediated gene delivery system

• Hiroaki Komuro,
• Masahiro Yamazoe,
• Kosuke Nozaki,
• Akiko Nagai and
• Tetsuo Sasano

Beilstein J. Nanotechnol. 2020, 11, 1685–1692, doi:10.3762/bjnano.11.150

• vector in HL-1 cells, we used plasmid-enhanced green fluorescent protein (pEGFP) as a model plasmid and evaluated the transfection efficiency via fluorescence microscopy. First, we used HAp (1 µg/mL) mixed with 0.075, 0.30, and 0.75 µg pEGFP, based on our previous results with endothelial cells

• . Fluorescence microscopy images showed that the highest transfection efficiency was observed with 0.75 µg of pEGFP (Figure 3). No gene expression was obtained by adding only pEGFP in HL-1 cells (data not shown). The results shown in Figure 3b demonstrated that the transfection efficiency of pEGFP increased in a

• commonly used as an indicator of the macropinocytic pathway [25], enabling the quantification of macropinocytosis. The quantification of TMR–dextran was performed by measuring the fluorescence intensity per cell, using fluorescence microscopy images, in accordance with a previous report. As shown in Figure

The influence of an interfacial hBN layer on the fluorescence of an organic molecule

• Christine Brülke,
• Oliver Bauer and
• Moritz M. Sokolowski

Beilstein J. Nanotechnol. 2020, 11, 1663–1684, doi:10.3762/bjnano.11.149

• organic molecule 3,4,9,10-perylene tetracarboxylic dianhydride (PTCDA) from the supporting Cu(111) surface by Raman and fluorescence (FL) spectroscopy. The Raman fingerprint-type spectrum of PTCDA served as a monitor for the presence of molecules on the surface. Several broad and weak FL lines between

• the optical excitation can occur. The different FL lines can be ascribed to different environments of the adsorption sites, namely molecules adsorbed at surface defects, in large ordered domains, and located in the second layer. Keywords: decoupling; fluorescence; hexagonal boron nitride; 3,4,9,10

• separated from those of the molecule leading to a reduced overlap. The overlap of molecular and metallic wave functions has, in particular, an impact on excited molecular states. For fluorescent molecules, this is observed as a strongly reduced quantum yield of the fluorescence (FL) due to non-radiant decay

Electrokinetic characterization of synthetic protein nanoparticles

• Daniel F. Quevedo,
• Cody J. Lentz,
• Adriana Coll de Peña,
• Yazmin Hernandez,
• Nahal Habibi,
• Rikako Miki,
• Joerg Lahann and
• Blanca H. Lapizco-Encinas

Beilstein J. Nanotechnol. 2020, 11, 1556–1567, doi:10.3762/bjnano.11.138

• low-conductivity EK media used in the subsequent experiments. To test the potential of using EK microfluidics as a high-throughput SPNP purification technique, our particles had to be fluorescently labeled to be visualized with a fluorescence microscope. To accomplish this, we incorporated

• assay using BSA standard for the standard curve. Particle fluorescence was confirmed using a Leica DMi8 inverted microscope (Wetzlar, Germany), which was paired with a Leica DFC7000 T camera and the software LASX provided by the manufacturer. Microdevice fabrication Microchannels with oval insulating

• as-synthesized SPNPs, using SPNPs made from BSA as an example. All SPNPs studied showed indistinguishable morphologies when viewed with SEM. (c) Image of SPNPs loaded with BSA-Alexa 488 to make them visible for characterization via electrokinetic microscale experiments. The fluorescence was confirmed

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

• ][48][49][50][51][52][53][54]. With prominent fluorescence properties, pyrene is often considered the "fruitfly of photochemists", and several materials have been prepared for applications in optoelectronic devices and organic electronics [47]. On metal surfaces under ultrahigh vacuum (UHV

• , studies comparing orbital-resolved STM/STS data to optical gaps are scarce [86]. In addition to this effect, the adsorption and supramolecular organization on hBN could sensitively affect the optical transitions [14][16][21]. For example, the fluorescence peak energy of perylene derivatives was reduced

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

• constituent can be determined after 24 h of incubation [149]. The cytofluorometry method is an advanced and important technique that allows for the accurate identification of a cell population with fluorescence tagging by using a flow cytometer and a photodetector [150]. In comparison to other techniques

Transient coating of γ-Fe₂O₃ nanoparticles with glutamate for its delivery to and removal from brain nerve terminals

• Konstantin Paliienko,
• Artem Pastukhov,
• Michal Babič,
• Daniel Horák,
• Olga Vasylchenko and
• Tatiana Borisova

Beilstein J. Nanotechnol. 2020, 11, 1381–1393, doi:10.3762/bjnano.11.122

• ratio (F), index of the membrane potential, was calculated as F = Ft/F0, where F0 and Ft were the fluorescence intensities of rhodamine 6G in the absence and presence of nerve terminals, respectively. F0 was calculated through extrapolation of the exponential decay function to t = 0. The fluorescence

• measurements were carried out using the potential-sensitive fluorescent dye rhodamine 6G, which binds to negatively charged membranes. The addition of synaptosomes to the dye-containing medium was accompanied by a partial decrease in fluorescence signal due to rhodamine 6G binding to the synaptosomal plasma

• membrane. First, the membrane potential index at the steady-state level was reached after a period of 3 min. As shown in Figure 4, the application of γ-Fe2O3 nanoparticles at a concentration of 1 µg/mL did not change the fluorescence signal of the dye. An increase in the nanoparticle concentration up to 50

Ultrasensitive detection of cadmium ions using a microcantilever-based piezoresistive sensor for groundwater

• Dinesh Rotake,
• Anand Darji and
• Nitin Kale

Beilstein J. Nanotechnol. 2020, 11, 1242–1253, doi:10.3762/bjnano.11.108

• been already identified. Sensors based on luminescence or fluorescence sensors have been used by many researchers to selectively detect HMIs [17][18][19][20][21][22]. However, this method also requires laboratory equipment for analysis and detection. Also, most of the reported fluorescent probes reply

• only on absorption and fluorescence change and need dynamic acquisition [23]. A magnetic field powered pressure sensor proposed by Khan et al. [24] is capable of measuring pressure in the range of kilopascals but the suitability for the very low pressure caused by HMIs needs to be examined. A reduced

• nanoparticles require the laboratory equipment such as fluorescence spectroscopy, which ultimately leads to a non-portable platform. Hence, our primary focus is the selective detection of the Cd(II) using the fabricated portable experimental platform. We used the following experimental procedure. A stock

Thermophoretic tweezers for single nanoparticle manipulation

• Jošt Stergar and
• Natan Osterman

Beilstein J. Nanotechnol. 2020, 11, 1126–1133, doi:10.3762/bjnano.11.97

• multiple heating spots by time-sharing (switching frequency 100 kHz) of the beam. Behind the AODs, the laser beam is directed by mirrors and an afocal system towards a custom-built fluorescence microscope. Finally, it is focused with a long working distance IR objective (Mitutoyo M Plan Apo NIR, 50×, NA

•  1b,c). Temperature measurements are performed using the temperature-dependent fluorescence of sulforhodamine B (Radiant dyes Chemie), which is calibrated in an independent measurement (accuracy ±2 K). Since the sapphire glass with a high thermal conductivity helps cooling the thin sample film, the

• implemented using a custom-built fluorescence microscope. By using an LED-optimized filter cube (Dapi/FITC/Cy3/Cy5 Quad LED HC Filter Set, AHF analysentechnik AG), Köhler illumination is utilized for fluorescence imaging using an LED as its light source. Light is collected from the sample plane by a 63

Applications of superparamagnetic iron oxide nanoparticles in drug and therapeutic delivery, and biotechnological advancements

• Maria Suciu,
• Corina M. Ionescu,
• Alexandra Ciorita,
• Septimiu C. Tripon,
• Dragos Nica,
• Hani Al-Salami and
• Lucian Barbu-Tudoran

Beilstein J. Nanotechnol. 2020, 11, 1092–1109, doi:10.3762/bjnano.11.94

• on the environment. Many nanoparticles showed great potential and proved their utility in biology and medicine. There are multiple types of nanoparticles routinely used in biology and related sciences for sensing, targeting or imaging, including quantum dots for fluorescence applications and electron

• been extensively examined regarding biocompatibility, targeted or intended cytotoxicity (ferroptosis), local hyperthermia treatments, photothermal or photodynamic therapy, and MRI. Also, there are increasingly more studies reporting on combinations with in vivo fluorescence imaging, sensing and

• for MRI and fluorescence imaging with good cytocompatibility. Park et al. [161] synthesized SPIONs coated with folate containing 64Cu for positronic emission tomography and MRI. Cai et al. [162] obtained 12 nm SPIONs coated with a near-infrared fluorescent dye for dual in vivo imagistics (MRI and