Streptavidin-coated gold nanoparticles: critical role of oligonucleotides on stability and fractal aggregation

• Roberta D'Agata,
• Pasquale Palladino and
• Giuseppe Spoto

Beilstein J. Nanotechnol. 2017, 8, 1–11, doi:10.3762/bjnano.8.1

• ) solutions at pH 7.4 (137 mM NaCl, 2.7 mM KCl, phosphate buffered 10 mM) were obtained from Amresco (Italy). Ultra-pure water (Milli-Q Element, Millipore) was used for all the experiments. Synthesis of AuNPs Glassware was cleaned with freshly prepared “piranha” solution; i.e., a mixture of 1:3 ratio of

A novel electrochemical nanobiosensor for the ultrasensitive and specific detection of femtomolar-level gastric cancer biomarker miRNA-106a

• Maryam Daneshpour,
• Kobra Omidfar and
• Hossein Ghanbarian

Beilstein J. Nanotechnol. 2016, 7, 2023–2036, doi:10.3762/bjnano.7.193

• different electrodes in the presence of 5.0 mM [Fe(CN)6]3−/4− containing 0.1 M KCl. As it can be seen, compared to bare SPCE, the peak current decreased after coating the SPCE with streptavidin and further probe immobilization, which apparently blocked and reduced the electron transfer of [Fe(CN)6]3−/4− to

• , ferric chloride hexahydrate (FeCl3·6H2O), ferrous chloride tetrahydrate (FeCl2·4H2O), and acetic acid were obtained from Acros Organics (USA). Chloroauric acid (HAuCl4), BSA, sodium dodecyl sulfate (SDS), low molecular weight chitosan, dialysis tube with molecular cut off 12000 Da, sodium azide, KCl, 1

• to characterize the stepwise fabrication of the miRNA-nanobiosensor. The basic analysis of the SPCEs in this study was performed via CV mode, at the potential range of −0.7 to +1.1 V and the scan rate of 50 mV/s using 5.0 mM [Fe(CN)6]3−/4− containing 0.1 M KCl. The performance of the biosensor was

Layered composites of PEDOT/PSS/nanoparticles and PEDOT/PSS/phthalocyanines as electron mediators for sensors and biosensors

• Celia García-Hernández,
• Cristina García-Cabezón,
• Fernando Martín-Pedrosa,
• José Antonio De Saja and
• María Luz Rodríguez-Méndez

Beilstein J. Nanotechnol. 2016, 7, 1948–1959, doi:10.3762/bjnano.7.186

• corresponding PEDOT/PSS, PEDOT/PSS/EM or PEDOT/PSS/EM-Enz modified electrode as the working electrode; the reference electrode was Ag|AgCl/KCl 3 mol/L and the counter electrode was a platinum sheet with a surface area of 1 cm2. Cyclic voltammetry was carried out from −0.6 V to +1.2 V (vs Ag/AgCl) with a scan

False positives and false negatives measure less than 0.001% in labeling ssDNA with osmium tetroxide 2,2’-bipyridine

• Anastassia Kanavarioti

Beilstein J. Nanotechnol. 2016, 7, 1434–1446, doi:10.3762/bjnano.7.135

• pH 7 buffered 1M KCl [34]. Specifically, Ir/Io = 0.12 for both, and corrected per unit mean translocation time τ = 312.5 and τ = 422.5 μs, for C(OsBp) and U(OsBp), respectively [34][38]. In contrast, Ir/Io = 0.08 and τ = 102.5 μs for T(OsBp) was obtained under the same conditions. In the context of

High performance Ce-doped ZnO nanorods for sunlight-driven photocatalysis

• Bilel Chouchene,
• Tahar Ben Chaabane,
• Lavinia Balan,
• Emilien Girot,
• Kevin Mozet,
• Ghouti Medjahdi and
• Raphaël Schneider

Beilstein J. Nanotechnol. 2016, 7, 1338–1349, doi:10.3762/bjnano.7.125

• experiments, we investigated the influence of various chlorides (NaCl, KCl, MgCl2 and CaCl2) used at a 10 mM concentration and at neutral pH on the photocatalytic activity of ZnO:Ce (5%) rods (Figure 11a). The amount of dye adsorbed by the photocatalyst and the photocatalytic activity are only slightly

In situ characterization of hydrogen absorption in nanoporous palladium produced by dealloying

• Eva-Maria Steyskal,
• Christopher Wiednig,
• Norbert Enzinger and
• Roland Würschum

Beilstein J. Nanotechnol. 2016, 7, 1197–1201, doi:10.3762/bjnano.7.110

• pushrod of a Linseis L75 vertical dilatometer applying a constant pressure of 100 mN. A well-annealed, flattened Pd wire served as working electrode contact to an Autolab PGSTAT204 potentiostat. Electrochemical charging was performed at room temperature using commercial Ag/AgCl (saturated KCl) reference

Voltammetric determination of polyphenolic content in pomegranate juice using a poly(gallic acid)/multiwalled carbon nanotube modified electrode

• Refat Abdel-Hamid and
• Emad F. Newair

Beilstein J. Nanotechnol. 2016, 7, 1104–1112, doi:10.3762/bjnano.7.103

• × 10–6 cm2/s in 0.2 M KCl [29]. The estimated active surface area values are 0.050 and 0.077 cm2 for bare GCE and PGA/MWCNT/GCE, respectively. Chronoamperometry For comparison, chronoamperometric measurements were employed for estimation of the electroactive surface area. The chronoamperometric

• behavior of 1.0 mM K3[Fe(CN)6] on GCE and PGA/MWCNT/GCE in 0.2 M KCl solution for the first wave at different duration times was performed. For chronoamperometric experiments, the electrode potential was stepped from 0.50 to 0.02 V on GCE and from 0.050 to −0.20 V on PGA/MWCNT/GCE for a fixed duration, τ

• ) coupled with NOVA 1.10 software. An electrochemical sensor is comprised of three electrodes: the working (bare or modified glassy carbon electrodes), the reference (Ag/AgCl, aqueous KCl, 3.5 M) and the auxiliary Pt wire electrodes. The surface morphology of a (PGA/MWCNT) composite film was examined using

Reconstitution of the membrane protein OmpF into biomimetic block copolymer–phospholipid hybrid membranes

• Matthias Bieligmeyer,
• Franjo Artukovic,
• Stephan Nussberger,
• Thomas Hirth,
• Thomas Schiestel and
• Michaela Müller

Beilstein J. Nanotechnol. 2016, 7, 881–892, doi:10.3762/bjnano.7.80

• molecular weight of the block copolymers. At low voltages, the channel conductance of OmpF in 1 M KCl was around 2.3 nS. In line with these experiments, integration of OmpF was also revealed by impedance spectroscopy. Our results indicate that blending synthetic polymer membranes with phospholipids allows

• potentials, as also demonstrated in the histograms (Figure 5D). At high membrane potentials, single-channel conductance was about 0.7 nS in 1 M KCl (Table 3), likely representing the conductance of a single pore of the OmpF trimer. These values were in line with conductance measurements of OmpF in pure DPhPC

• membranes in 1 M KCl (Figure 5C and Figure 5D) [60][62][63]. It should be noted that the probability of OmpF to insert into PIPEO/DPhPC membranes was significantly lower than that of inserting into planar DPhPC bilayers. A possible explanation is the presence of minute amounts of chloroform in the PIPEO

Mismatch detection in DNA monolayers by atomic force microscopy and electrochemical impedance spectroscopy

• Maryse D. Nkoua Ngavouka,
• Pietro Capaldo,
• Elena Ambrosetti,
• Giacinto Scoles,
• Loredana Casalis and
• Pietro Parisse

Beilstein J. Nanotechnol. 2016, 7, 220–227, doi:10.3762/bjnano.7.20

• rinsed with the buffer solution used for the measurements, 100 mM KCl, and the capacitance at the electrode/electrolyte interface was measured. In the hybridization step the cell is filled with a drop of the same hybridizing buffer solution, 100 mM KCl, containing the complementary or partially

• mismatches (a) and in presence of partially complementary sequences (b). The red signal represents the differential capacitance of a low-density 44 bases ssDNA SAM functionalized WE measured in 100 mM KCl. (a) In blue we report the hybridization with the fully matching sequence, in green the hybridization

Chemical bath deposition of textured and compact zinc oxide thin films on vinyl-terminated polystyrene brushes

• Nina J. Blumenstein,
• Caroline G. Hofmeister,
• Peter Lindemann,
• Cheng Huang,
• Johannes Baier,
• Andreas Leineweber,
• Stefan Walheim,
• Christof Wöll,
• Thomas Schimmel and
• Joachim Bill

Beilstein J. Nanotechnol. 2016, 7, 102–110, doi:10.3762/bjnano.7.12

• Electrokinetic Analyzer (Anton Paar GmbH). Samples were glued on the stamps of an adjustable gap cell (10 mm × 20 mm) with double-sided tape and a gap height of 100 µm was used. A 1 mM KCl solution was purged with nitrogen prior and during the measurements. For automatic titration, a 0.1 M HCl solution was used

Single pyrimidine discrimination during voltage-driven translocation of osmylated oligodeoxynucleotides via the α-hemolysin nanopore

• Yun Ding and
• Anastassia Kanavarioti

Beilstein J. Nanotechnol. 2016, 7, 91–101, doi:10.3762/bjnano.7.11

• done using conditions for unmodified oligos as described in [14]: 10 μM oligo in 1.00 M KCl, at pH 7.4 with 10 mM potassium phosphate buffer at 22 ± 1 °C. Up to four different probing voltages, namely 100, 120, 140, and 160 mV (trans vs cis) were tested. The observation of decreasing dwell times with

• observed with the two R2 oligos (see below in Figure 6). It is plausible that this hydrophobic association is favored in the 10 μM oligo concentration and in the presence of 1 M KCl used for the present experiments. Lower oligo and/or lower salt concentrations may suppress association, yield higher

• composition. Part B, Chemicals, materials and instrumentation for nanopore measurements: Nanopore experiments were conducted with 10 μM DNA in 1.0 M KCl, 10 mM potassium phosphate buffer at pH 7.4 and at 22 ± 1 °C, as described in detail in [14], and summarized here. WT α-hemolysin was purchased from List

Influence of wide band gap oxide substrates on the photoelectrochemical properties and structural disorder of CdS nanoparticles grown by the successive ionic layer adsorption and reaction (SILAR) method

• Mikalai V. Malashchonak,
• Alexander V. Mazanik,
• Olga V. Korolik,
• Еugene А. Streltsov and
• Anatoly I. Kulak

Beilstein J. Nanotechnol. 2015, 6, 2252–2262, doi:10.3762/bjnano.6.231

• water, air-dried and heat-treated at 450 °C for 1 h in air. Mesoporous zinc oxide films were prepared by the electrochemical cathodic deposition from water–ethanol (1:1 by volume) electrolyte containing 0.1 mol/L Zn(NO3)2, 0.1 mol/L KCl and 4 g/L poly(vinylpyrrolidone) at 50 °C [18][38]. Deposition was

• carried out by potentiostatic cathodic polarization of FTO electrodes at −1000 mV vs Ag/AgCl/KCl (sat.) reference electrode (+0.201 V vs SHE) for 25 min. Because of the formation of hydroxyl ions, a local increase of рН occurs, and the hydrolysis of Zn2+ ions is promoted and precipitation of Zn5(OH)8Cl2

• geometry. The photoelectrochemical measurements were performed according to the procedure described in [39]. A standard two-compartment three-electrode cell containing a platinum counter electrode and an Ag/AgCl/KCl (sat.) electrode as the reference electrode and controlled by a conventional programmable

Electrochemical behavior of polypyrrol/AuNP composites deposited by different electrochemical methods: sensing properties towards catechol

• Celia García-Hernández,
• Cristina García-Cabezón,
• Cristina Medina-Plaza,
• Fernando Martín-Pedrosa,
• Yolanda Blanco,
• José Antonio de Saja and
• María Luz Rodríguez-Méndez

Beilstein J. Nanotechnol. 2015, 6, 2052–2061, doi:10.3762/bjnano.6.209

• be the most suitable electrodeposition technique to prepare voltammetric sensors. Electrochemical behavior of Ppy/AuNPs prepared using different techniques The electrochemical behavior of Ppy and Ppy/AuNP films was analyzed using cyclic voltammetry in 0.1 mol/L KCl solution. The responses are

• separation between the anodic and the cathodic waves that appeared at −0.15 and −0.8 V, respectively [33] . A part from the broadening of the peaks, the effects caused by AuNPs were similar to those observed in KCl (e.g., increase in the intensity of the peaks accompanied by a decrease in the separation

• and in the intensity of the voltammetric signals. These variations in conductivity and intensity of voltammograms are directly related to the number of AuNPs inserted in the Ppy films. Irreproducibility observed in the EIS and voltammetric measurements carried out in KCl using films deposited on

Growth and morphological analysis of segmented AuAg alloy nanowires created by pulsed electrodeposition in ion-track etched membranes

• Ina Schubert,
• Loic Burr,
• Christina Trautmann and
• Maria Eugenia Toimil-Molares

Beilstein J. Nanotechnol. 2015, 6, 1272–1280, doi:10.3762/bjnano.6.131

• nanowires in the pores of the template was performed in a three-electrode set-up using a potentiostat (GAMRY Instruments, Reference 600TM) and a platinum wire as counter electrode. All potentials given here are reported versus the reference electrode, being Ag/AgCl (sat. KCl). Before starting the deposition

Probing fibronectin–antibody interactions using AFM force spectroscopy and lateral force microscopy

• Andrzej J. Kulik,
• Małgorzata Lekka,
• Kyumin Lee,
• Grazyna Pyka-Fościak and
• Wieslaw Nowak

Beilstein J. Nanotechnol. 2015, 6, 1164–1175, doi:10.3762/bjnano.6.118

• fibronectin isolated from human plasma. Other reagents Other reagents used in the experiments were: (a) phosphate buffered saline (PBS, ICN Biomedicals, pH 7.4, containing 10 mM of PO42−, 137 mM of NaCl and 27 mM of KCl) was used to prepare all protein solutions; (b) 3-aminopropyltriethoxysilane (APTES, Sigma

Properties of plasmonic arrays produced by pulsed-laser nanostructuring of thin Au films

• Katarzyna Grochowska,
• Katarzyna Siuzdak,
• Peter A. Atanasov,
• Carla Bittencourt,
• Anna Dikovska,
• Nikolay N. Nedyalkov and
• Gerard Śliwiński

Beilstein J. Nanotechnol. 2014, 5, 2102–2112, doi:10.3762/bjnano.5.219

• solutions of 10 mM K3[Fe(CN)6] + 1 M KCl and 0.1 M NaOH without and with 2 mM of glucose added. The electrolytes were purged with argon for about 1 h prior the measurements, and during the electrochemical tests the Ar-cushion above the electrolyte has been applied. For the samples on ITO substrates, the Au

• films and NP arrays stayed as a working electrode, and the Pt mesh and Ag/AgCl/0.1 M KCl served as the counter and reference electrodes, respectively. Figure 7 shows data collected for the reference ITO electrodes covered by continuous gold films of a thickness of 10 and 20 nm and also for ITO modified

• modified by Au NPs produced by laser nanostructuring of these films, for electrodes immersed in 10 mM K3[Fe(CN)6] + 1 M KCl and recorded at a scan rate of 50 mV/s; b) CV curves of the ITO electrode modified by Au NPs produced from 20 nm thick films, in 0.1 M NaOH without and with 2 mM of glucose, recorded

Effect of channel length on the electrical response of carbon nanotube field-effect transistors to deoxyribonucleic acid hybridization

• Hari Krishna Salila Vijayalal Mohan,
• Jianing An,
• Yani Zhang,
• Chee How Wong and
• Lianxi Zheng

Beilstein J. Nanotechnol. 2014, 5, 2081–2091, doi:10.3762/bjnano.5.217

• , Biotechnology grade) consisting of 137 mM NaCl, 2.7 mM KCl, and 10 mM phosphate buffer in 1000 mL distilled H2O was purchased from BST Scientific Ltd., Singapore. SWCNT-based FETs were incubated with 5 mM of the linker molecule PASE in pure DMF for 3 hours at room temperature followed by washing with DMF and

Real-time monitoring of calcium carbonate and cationic peptide deposition on carboxylate-SAM using a microfluidic SAW biosensor

• Anna Pohl and
• Ingrid M. Weiss

Beilstein J. Nanotechnol. 2014, 5, 1823–1835, doi:10.3762/bjnano.5.193

• , Dudelange, Luxembourg) [46] was prepared in Gly–Gly buffers (20 mM glycylglycine, 350 mM NaCl, 10 mM KCl), previously adjusted to either pH 7.75, 8.2 or 9.0. Each peptide was diluted in the respective buffers to final concentrations of 50 µM, 100 µM or 200 µM. Citric acid A 10 mM citric acid solution was

The protein corona protects against size- and dose-dependent toxicity of amorphous silica nanoparticles

• Dominic Docter,
• Christoph Bantz,
• Dana Westmeier,
• Hajo J. Galla,
• Qiangbin Wang,
• James C. Kirkpatrick,
• Peter Nielsen,
• Michael Maskos and
• Roland H. Stauber

Beilstein J. Nanotechnol. 2014, 5, 1380–1392, doi:10.3762/bjnano.5.151

• (103.5 mM NaCl, 5.3 mM KCl, 5.6 mM Na2HPO4, 1.4 mM KH2PO4, 23.8 mM NaHCO3, pH 7.4), DMEM with or without 10% FCS, and the measurements were conducted at 25 °C by using 0.6 mg/mL ASP. Cell culture The colonic carcinoma cell line Caco-2 and the colorectal adenocarcinoma cell line HT-29 were obtained from

Model systems for studying cell adhesion and biomimetic actin networks

• Dorothea Brüggemann,
• Johannes P. Frohnmayer and
• Joachim P. Spatz

Beilstein J. Nanotechnol. 2014, 5, 1193–1202, doi:10.3762/bjnano.5.131

• co-workers concluded that the lipid membrane also plays an active part in organising actin networks. Already in 1999, Miyata et al. had observed similar protrusive formations at the outside of GUVs with encaged actin filaments. These protrusions developed within 30 to 100 s after KCl was introduced

Nanocavity crossbar arrays for parallel electrochemical sensing on a chip

• Enno Kätelhön,
• Dirk Mayer,
• Marko Banzet,
• Andreas Offenhäusser and
• Bernhard Wolfrum

Beilstein J. Nanotechnol. 2014, 5, 1137–1143, doi:10.3762/bjnano.5.124

• perpendicular cathodes. The device is then calibrated in plain 100 mM KCl solution as well as in a 1 mM potassium hexacyanoferrate solution in order to linearly interpolate the response curve for the individual sensors. After adding the 1 mM potassium hexacyanoferrate solution, three sensors that are located

• dependency of an intersection in sequential data acquisition. Data was recorded during cyclic voltammograms at different concentrations of potassium hexacyanoferrate in 100 mM KCl and represents the absolute difference between the cathodic peak current and a measurement using only the background electrolyte

The study of surface wetting, nanobubbles and boundary slip with an applied voltage: A review

• Yunlu Pan,
• Bharat Bhushan and
• Xuezeng Zhao

Beilstein J. Nanotechnol. 2014, 5, 1042–1065, doi:10.3762/bjnano.5.117

• were used in study. First one is normal saline solution (sodium chloride (NaCl) 8000 mg/L, potassium chloride (KCl) 200 mg/L, sodium phosphate dibasic (Na2HPO4·7H2O)2, 160 mg/L, potassium phosphate monobasic (KH2PO4) 100 mg/L) (Invitrogen, Grand Island, NY). Another two oxygenated saline solutions

Enhancement of photocatalytic H₂ evolution of eosin Y-sensitized reduced graphene oxide through a simple photoreaction

• Weiying Zhang,
• Yuexiang Li,
• Shaoqin Peng and
• Xiang Cai

Beilstein J. Nanotechnol. 2014, 5, 801–811, doi:10.3762/bjnano.5.92

• with a glassy carbon electrode (diameter 2 mm) as the working electrode, a platinum wire as the counter electrode, and an Ag/AgCl electrode as the reference electrode. The electrolyte was a solution of 0.1 M phosphate buffer solution (PBS, pH 7), 0.1 M KCl, 10 mM K3Fe(CN)6 and 10 mM K4Fe(CN)6

Manipulation of isolated brain nerve terminals by an external magnetic field using D-mannose-coated γ-Fe₂O₃ nano-sized particles and assessment of their effects on glutamate transport

• Tatiana Borisova,
• Natalia Krisanova,
• Arsenii Borуsov,
• Roman Sivko,
• Ludmila Ostapchenko,
• Michal Babic and
• Daniel Horak

Beilstein J. Nanotechnol. 2014, 5, 778–788, doi:10.3762/bjnano.5.90

• labeled with D-mannose coated γ-Fe2O3 nanoparticles to the magnet was investigated. KCl at a concentration of 35 mM was typically used for the depolarization of the plasma membrane of synaptosomes [13]. In this context, an increased extracellular level of L-[14C]glutamate in the presence of 35 mM KCl was

• taken into consideration. As a result, a decrease in the label by approximately 8% in vicinity of the magnet was revealed after 5 min incubation of synaptosomes with D-mannose-coated γ-Fe2O3 nanoparticles in the presence of 35 mM KCl. Therefore, it can be concluded that we obtained normally functioning

• magnetic fields to destroy cells could provide an additional tool for medical treatment. The mechanism by which D-mannose-coated γ-Fe2O3 nanoparticles interacted with nerve terminals should be further elucidated. However, it was demonstrated that elevated ionic strength (35 mM KCl) attenuated the

Constant-distance mode SECM as a tool to visualize local electrocatalytic activity of oxygen reduction catalysts

• Michaela Nebel,
• Thomas Erichsen and
• Wolfgang Schuhmann

Beilstein J. Nanotechnol. 2014, 5, 141–151, doi:10.3762/bjnano.5.14

• , Barsbüttel, Germany). The electrochemical characterization of the SECM tips, microelectrodes, and recessed microelectrodes as sample surfaces were performed by means of cyclic voltammetry in an electrolyte containing 5 mM [Ru(NH3)6]Cl3 (ABCR, Karlsruhe, Germany) and 100 mM KCl (Riedel-de Haën, Seelze

• , c: bulk concentration of the electroactive species and r: radius of the active electrode surface). A diffusion coefficient of 9.1 × 10−6 cm2s−1 for [Ru(NH3)6]3+ in KCl [43] was used. In all experiments a coiled Pt-wire (Ø 250 µm) counter electrode and a home build miniaturized Ag/AgCl (3 M KCl

• were removed by an ultrasound washing step in water and electrochemical cleaning in H2SO4. The recessed electrode was characterised by means of CV in 5 mM [Ru(NH3)6]Cl3 and 100 mM KCl. The formed microcavity was filled with the catalyst powder by pressing the etched electrode in a small amount of