Comparison of four methods for the biofunctionalization of gold nanorods by the introduction of sulfhydryl groups to antibodies

• Xuefeng Wang,
• Zhong Mei,
• Yanyan Wang and
• Liang Tang

Beilstein J. Nanotechnol. 2017, 8, 372–380, doi:10.3762/bjnano.8.39

• solution and the CTAB bilayer density [15]. The common ligand exchange is the replacement of the CTAB of GNR with thiol-terminated ligands, such as thiolated poly(ethylene glycol) and mercaptoundecanoic acid [10][11]. These agents can link the amino groups of biomolecules with the carboxylic group from

• cationic surfactant bilayer [17][24], because of the replacement of CTAB by thiolated anti-IgG [17][25]. Anti-IgG were detected in thiolation and nanoconjugates with GNRs, but not in free GNRs, by gel electrophoresis followed by Coomassie brilliant blue staining (Figure S1, Supporting Information File 1

Impact of contact resistance on the electrical properties of MoS₂ transistors at practical operating temperatures

• Filippo Giannazzo,
• Gabriele Fisichella,
• Aurora Piazza,
• Salvatore Di Franco,
• Giuseppe Greco,
• Simonpietro Agnello and
• Fabrizio Roccaforte

Beilstein J. Nanotechnol. 2017, 8, 254–263, doi:10.3762/bjnano.8.28

• to transfer the exfoliated MoS2 flakes onto the SiO2 surface that was previously cleaned using solvents and a soft O2 plasma treatment. Finally, source and drain contacts were obtained by deposition and lift-off of a Ni(50 nm)/Au(100 nm) bilayer. The temperature-dependent electrical characterization

Tunable plasmons in regular planar arrays of graphene nanoribbons with armchair and zigzag-shaped edges

• Cristian Vacacela Gomez,
• Michele Pisarra,
• Mario Gravina and
• Antonello Sindona

Beilstein J. Nanotechnol. 2017, 8, 172–182, doi:10.3762/bjnano.8.18

• above about 2 eV. These excitations, shown in Figure 2b–e, are analogous to the well-known π and π–σ plasmons of graphene [51][52], as displayed in Figure 2a. Similar features occur in bilayer graphene [51], multilayer graphene [52], graphene–metal interfaces [53][54][55][56][57][58][59] and graphite

Nitrogen-doped twisted graphene grown on copper by atmospheric pressure CVD from a decane precursor

• Ivan V. Komissarov,
• Nikolai G. Kovalchuk,
• Vladimir A. Labunov,
• Ksenia V. Girel,
• Olga V. Korolik,
• Mikhail S. Tivanov,
• Algirdas Lazauskas,
• Mindaugas Andrulevičius,
• Tomas Tamulevičius,
• Viktoras Grigaliūnas,
• Šarunas Meškinis,
• Sigitas Tamulevičius and
• Serghej L. Prischepa

Beilstein J. Nanotechnol. 2017, 8, 145–158, doi:10.3762/bjnano.8.15

• are formed due to the overlap of the Dirac cones in the k-space. The controlled injection of defects, which cause strain, is an extra degree of freedom in addition to the number of layers. This may account for the unique properties of TG. In particular, it was shown that the strained TG bilayer could

Surface-enhanced Raman scattering of self-assembled thiol monolayers and supported lipid membranes on thin anodic porous alumina

• Marco Salerno,
• Amirreza Shayganpour,
• Barbara Salis and
• Silvia Dante

Beilstein J. Nanotechnol. 2017, 8, 74–81, doi:10.3762/bjnano.8.8

• ), and then with phospholipid vesicles of different composition to form a supported lipid bilayer (SLB). At each step, the SERS substrate functionality was assessed, demonstrating acceptable enhancement (≥100×). The chemisorption of thiols during the first step and the formation of SLB from the vesicles

• the physisorption of coating layers of functional materials [20][21]. The main component of the biological membrane that separates and protects the interior of all living cells from the outside environment is a phospholipid bilayer. For this reason, as well as for the complexity of real samples of

• resemble the plasma membrane composition both for charge and acyl chain length and unsaturation grade. However, the reason for the choice of DOTAP is technical, associated with the fabrication of artificial bilayer membranes [29][30]. The lipids are larger molecules than the thiols and present richer

Annealing-induced recovery of indents in thin Au(Fe) bilayer films

• Anna Kosinova,
• Ruth Schwaiger,
• Leonid Klinger and
• Eugen Rabkin

Beilstein J. Nanotechnol. 2016, 7, 2088–2099, doi:10.3762/bjnano.7.199

• strain in thin films. Here, we present the results of a study investigating the recovery of indentation-induced defects in Au(Fe) bilayer films. The motivation for our work is two-fold: (i) to explore the concept of thermo-mechanical treatment of thin films by combining localized plastic strain

• by Iijima and Yamazaki [17]. At the temperature of 700 °C employed in the present study, the full intermixing of a 50 nm thick bilayer takes less than 1 s, and, therefore, in what follows we will refer to the Au(Fe) bilayers as a single-phase face-centered cubic dilute solid solution of Fe in Au, or

Intercalation and structural aspects of macroRAFT agents into MgAl layered double hydroxides

• Dessislava Kostadinova,
• Ana Cenacchi Pereira,
• Muriel Lansalot,
• Franck D’Agosto,
• Elodie Bourgeat-Lami,
• Fabrice Leroux,
• Christine Taviot-Guého,
• Sylvian Cadars and
• Vanessa Prevot

Beilstein J. Nanotechnol. 2016, 7, 2000–2012, doi:10.3762/bjnano.7.191

• compared to pristine MgAl-NO3 LDH from 1.36 nm to 2.33 nm. Depending on the nature of the units involved into the macroRAFT copolymer (only AA or AA and BA), the intercalation led to monolayer or bilayer arrangements within the interlayer space. The macroRAFT intercalation and the molecular structure of

• with a bilayer arrangement of the copolymers. The two most intense peaks are due to the hydroxide layers containing Mg/Al cations. The carboxylate groups from the AA units and the end group of CTPPA would cause maxima at the outer parts of the interlayer space at a distance of ≈0.39 nm from the center

• monolayer in the interlamellar domain whereas the presence of BA units into the chain induced a bilayer arrangement whatever the chain length. Contrarily to what may be expected, based on NMR experiments, the negatively-charged AA units did not appear to interact sizeably more strongly with the LDH host

Electric field induced structural colour tuning of a silver/titanium dioxide nanoparticle one-dimensional photonic crystal

• Eduardo Aluicio-Sarduy,
• Simone Callegari,
• Diana Gisell Figueroa del Valle,
• Andrea Desii,
• Ilka Kriegel and
• Francesco Scotognella

Beilstein J. Nanotechnol. 2016, 7, 1404–1410, doi:10.3762/bjnano.7.131

• force microscopy (AFM) images of a Ag layer, a TiO2 layer and the top surface of a five bilayer Ag/TiO2 photonic crystal, all deposited on glass/ITO substrates, are presented in the Supporting Information File 1 (Figure S1) and show that the silver nanoparticle layer has the highest surface roughness

• among the different samples. This is due to the large size of the silver nanoparticles and the formation of large aggregates. Notably, the lowest surface roughness was found for the top TiO2 surface layer of the five bilayer photonic crystal (Figure S1c of Supporting Information File 1). The formation

• nm. This value is lower than the sum of five single Ag and TiO2 layers deposited directly on the substrate (60 nm and 120 nm, respectively), confirming the conclusions of the AFM analysis. Nevertheless, we consider that this intermixing is confined to the interface region and that a bilayer structure

On the pathway of cellular uptake: new insight into the interaction between the cell membrane and very small nanoparticles

• Claudia Messerschmidt,
• Daniel Hofmann,
• Anja Kroeger,
• Katharina Landfester,
• Volker Mailänder and
• Ingo Lieberwirth

Beilstein J. Nanotechnol. 2016, 7, 1296–1311, doi:10.3762/bjnano.7.121

• is approximately 4 nm (Figure 5A,D). This roughly is the thickness of two lipid tails in a phospholipid membrane. The distinct contrast in the STEM micrograph is attributed to the existence of C–C double bonds in the bilayer structure, which are stained by OsO4. Furthermore, micrographs show

• assume that this large area coverage hinders the final vesicle pinch-off from the cell membrane. The additional silica layer on the cell membrane prevents the intimate membrane–membrane contact necessary for the coalescence of the membrane lipid bilayer at the point of pinch-off. Furthermore, the

• higher compared to the cell membrane. Nonetheless, it is remarkable that quite a little difference in NP size results in completely different uptake morphologies. From molecular dynamics simulations of two curvature imprinting particles on a lipid bilayer membrane we learn, that the membrane mediates

Thickness dependence of the triplet spin-valve effect in superconductor–ferromagnet–ferromagnet heterostructures

• Daniel Lenk,
• Vladimir I. Zdravkov,
• Jan-Michael Kehrle,
• Günter Obermeier,
• Aladin Ullrich,
• Roman Morari,
• Hans-Albrecht Krug von Nidda,
• Claus Müller,
• Mikhail Yu. Kupriyanov,
• Anatolie S. Sidorenko,
• Siegfried Horn,
• Rafael G. Deminov,
• Lenar R. Tagirov and
• Reinhard Tidecks

Beilstein J. Nanotechnol. 2016, 7, 957–969, doi:10.3762/bjnano.7.88

• (PWF), which decays exponentially and oscillates as a function of space [5][6][7]. As a consequence, interference effects occur, if the PWF is reflected at the outer border of the F-layer of a S/F bilayer, yielding an oscillating superconducting transition temperature as a function of the F-layer

• discussion of the decay length see also [52]). However, only the singlet component enters the self-consistency equation for the superconducting gap and is, thus, the only component directly affecting Tc [14][15]. For uniform magnetization of the F-layer in a S/F bilayer and collinear magnetizations in F/S/F

• solubility of Nb in Cu is extremely small under ambient conditions, the Nb–Ni phase diagram shows a certain solubility of Nb in Ni and vice versa [69]. In this case the bilayer with the thinnest Cu41Ni59 layer would show the largest reduction of mat. However, the opposite is observed. There may be several

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

• more and more interest, as the properties of such assemblies can be steadily varied between the characteristics of a lipid bilayer and that of synthetic polymer membranes. By simply mixing lipids and amphiphilic polymers, a plethora of possible chemical and mechanical characteristics of polymeric

• a circular aperture with a diameter of 400 µm in the partitioning wall of a custom-built black lipid bilayer Teflon chamber. The volume of each compartment, separated by the partionining wall, was 5 mL [67]. PIPEO/DPhPC in chloroform (10 µL) was applied around the aperture of the chamber and allowed

• (Axon CV203 BU) connected to the bilayer chambers by a pair of custom-made Ag/AgCl electrodes. Current signals were filtered at 2 kHz and digitally sampled at 10 kHz with an Axon Digidata 1322A digitizer controlled by the Clampex 10.2 software (Molecular Devices, Sunnyvale, USA). Synthesis of PIPEO

Highly compact refractive index sensor based on stripe waveguides for lab-on-a-chip sensing applications

• Chamanei Perera,
• Kristy Vernon,
• Elliot Cheng,
• Juna Sathian,
• Esa Jaatinen and
• Timothy Davis

Beilstein J. Nanotechnol. 2016, 7, 751–757, doi:10.3762/bjnano.7.66

• . First, the RI sensor designs and alignment marks were patterned on a 300 nm bilayer PMMA resist (950 k A4 / 495 k A4 PMMA resist from Microchem GmbH) using electron beam lithography (JEOL-7800 FE-SEM with Raith Quantum Elphy) with a beam current of ≈75 pA and 20 kV acceleration voltage under optimal

• dose of 280 μC/cm2. The patterned PMMA bilayer was then developed for 30 seconds in MIBK/IPA 1:3 solution. 30 nm Ag was evaporated on the developed sample using the PVD 75 e-beam evaporator under a slow rate of 0.1 angstrom per second. A scanning electron microscope image was obtained (Figure 3) which

• shows the successfully survived sensor designs after lift-off in acetone bath. Second, a 300 nm bilayer PMMA resist was spincoated on top of the structures to pattern the sample window on top of the sample arm. Then, the sample windows were patterned in the second EBL step. Finally, the patterned

Gold nanoparticles covalently assembled onto vesicle structures as possible biosensing platform

• M. Fátima Barroso,
• M. Alejandra Luna,
• Juan S. Flores Tabares,
• Cristina Delerue-Matos,
• N. Mariano Correa,
• Fernando Moyano and
• Patricia G. Molina

Beilstein J. Nanotechnol. 2016, 7, 655–663, doi:10.3762/bjnano.7.58

• (SH). After, the AuNPs photochemically synthesized in pure glycerol were mixed and anchored onto SH–DOPC vesicles. The data provided by voltammetry, spectrometry and microscopy techniques indicated that the AuNPs were successfully covalently anchored onto the vesicle bilayer and decorated vesicles

• hydrophobic bilayer as well as water-soluble substances. These structures are the best mimetic agents of biological membranes and represent the environment in which many proteins and enzymes show activity [1][2]. The advantages that the vesicles have over synthetic materials are: lack of toxicity

• of the AuNPs synthesis (irradiation time, HAuCl4 concentration), these AuNPs were covalently immobilized onto large unilamellar vesicles (LUVs) composed by the phospholipid DOPC (1,2-dioleoyl-sn-glycero-3-phosphocholine). For this purpose 1-undecanethiol (SH) was incorporated into the bilayer in

Cantilever bending based on humidity-actuated mesoporous silica/silicon bilayers

• Christian Ganser,
• Gerhard Fritz-Popovski,
• Roland Morak,
• Parvin Sharifi,
• Benedetta Marmiroli,
• Barbara Sartori,
• Heinz Amenitsch,
• Thomas Griesser,
• Christian Teichert and
• Oskar Paris

Beilstein J. Nanotechnol. 2016, 7, 637–644, doi:10.3762/bjnano.7.56

• cylindrical pores with elliptical cross-section on an ordered pore lattice. The film is deposited on silicon-based commercial atomic force microscope (AFM) cantilevers using dip coating. This bilayer cantilever is mounted in a humidity controlled AFM, and its deflection is measured as a function of relative

• layer is related to the cantilever deflection using simple bilayer bending theory. We also develop a simple quantitative model for cantilever deflection which only requires cantilever geometry and nanostructural parameters of the porous layer as input parameters. Keywords: AFM cantilever; bilayer

• is to increase the number of adsorbed molecules by increasing the total interaction area of molecules with the surface. This leads to the concept of using bilayer structures, with one of the layers having a large accessible (internal) surface area. In the natural world of plants for instance

First-principles study of the structure of water layers on flat and stepped Pb electrodes

• Xiaohang Lin,
• Ferdinand Evers and
• Axel Groß

Beilstein J. Nanotechnol. 2016, 7, 533–543, doi:10.3762/bjnano.7.47

• dissolve within the run time of 8 ps at 140 K. Figure 5a shows that there is no longer a flat water layer, but a kind of bilayer with the distance between the O atom of the upper water molecules and the Pb surface being 5.2 Å, which is 2.4 Å larger than for the lower water molecules. The plotted

Determination of the compositions of the DIGM zone in nanocrystalline Ag/Au and Ag/Pd thin films by secondary neutral mass spectrometry

• Gábor Y. Molnár,
• Shenouda S. Shenouda,
• Gábor L. Katona,
• Gábor A. Langer and
• Dezső L. Beke

Beilstein J. Nanotechnol. 2016, 7, 474–483, doi:10.3762/bjnano.7.41

• the Pd(30 nm)/Ag(30 nm)/substrate film system at different temperatures. Figure 5 shows the average compositions inside the Ag and Pd layers as a function of the annealing time at different temperatures for the Ag(15 nm)/Pd(15 nm)/substrate bilayer (Figure 5a) at 150 °C and for the Pd(30 nm/Ag(30 nm

• homogenization in bilayer films is possible on both sides, and the compositions in the DIGM zones can be followed by SNMS depth profiling. Let us check whether the relations in Equation 1 and Equation 2 give a quantitative explanation for our experimental results or not. It can be seen that the above relations

• annealing times until full homogenization is reached. That is, the formation of a solid solution corresponding to the original element ratio in the bilayer. However, we did not observe such a two- or multi-step homogenization process (see Figure 2 and Figure 5). Even prolonged heat treatments did not result

Characterisation of thin films of graphene–surfactant composites produced through a novel semi-automated method

• Nik J. Walch,
• Alexei Nabok,
• Frank Davis and
• Séamus P. J. Higson

Beilstein J. Nanotechnol. 2016, 7, 209–219, doi:10.3762/bjnano.7.19

• composite films in the visible spectral range similar to that reported in [22][23]. The absorption peak of graphene reported earlier [22][23] at about 260 nm is outside the spectral range of our ellipsometric instrument (370–1000 nm). The example of ellipsometry data fitting for one PAH/graphene bilayer

• deposited on Si is shown in Figure 9b with the dotted (fitting) lines almost perfectly reproducing the experimental spectra (solid lines). The thicknesses were found to be of 6.65, 9.3, and 10.88 nm for 1st, 2nd, and 3rd PAH/graphene bilayer, respectively. Although the d value of the first bilayer appeared

• 2.5 nm per PEI/graphene bilayer which was reported earlier. Conclusion A simple semi-automated technique for graphene production by aqueous sonochemical exfoliation of graphite in the presence of ionic surfactants, e.g., CTAB or SDS, was developed. Full automation could be potentially achieved by

Synthesis and applications of carbon nanomaterials for energy generation and storage

• Marco Notarianni,
• Jinzhang Liu,
• Kristy Vernon and
• Nunzio Motta

Beilstein J. Nanotechnol. 2016, 7, 149–196, doi:10.3762/bjnano.7.17

• quality. In fact, the graphene produced is mostly polycrystalline with aperiodic heptagon/pentagon pairs [143] or overlapped bilayer regions [144] at the grain boundaries (Figure 22b). It has also been demonstrated that the presence of grain boundaries can reduce the mechanical and electrical properties

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

• Biological Laboratories in the monomer form of lyophilized power and dissolved in water at 1 mg/mL. 1,2-Diphytanoyl-sn-glycero-3-phosphocholine (DPhPC) was dissolved in decane at 10 mg/mL and used to form the bilayer. The bilayer was supported by a glass nanopore membrane (GNM), which was modified with a 2

• , University of Utah. The KCl solution was used as the electrolyte to fill the solution reservoir and the GNM capillary. A voltage was applied across the GNM between two Ag/AgCl electrodes placed inside and outside of the capillary. A lipid bilayer was deposited across the GNM orifice as indicated by a

• resistance increase from ca. 10 MΩ (associated with the open GNM) to ca. 100 GΩ. A pressure of 20 to 40 mmHg was applied to the inside of the GNM capillary using a syringe, allowing the lipid bilayer to be functional for the protein channel reconstitution. Next, 0.2 µL of α-HL monomer solution at 1 mg/mL was

Fabrication and characterization of novel multilayered structures by stereocomplexion of poly(D-lactic acid)/poly(L-lactic acid) and self-assembly of polyelectrolytes

• Elena Dellacasa,
• Li Zhao,
• Gesheng Yang,
• Laura Pastorino and
• Gleb B. Sukhorukov

Beilstein J. Nanotechnol. 2016, 7, 81–90, doi:10.3762/bjnano.7.10

• in Figure 9b, the thickness of the PLL/(PDLA/PLLA)10 multilayer is approximately 100 nm. Hence, the thickness of each PDLA/PLLA bilayer is estimated to be 10 nm. Interestingly, the thickness of the PLA layers on the silicon substrate (see Ellipsiometry) was not as thick as that of the microcapsules

• adsorption steps (15 min in duration) of anionic PSS (2 mg/mL in 0.5 M NaCl) and cationic PAH (2 mg/ml in Milli-Q water) followed. After each adsorption step, three washings in Milli-Q water (1500 rpm for 1 min) were carried out. Once the four bilayer structures were deposited, one layer of PLL (5 mg/mL in

pH-Triggered release from surface-modified poly(lactic-co-glycolic acid) nanoparticles

• Manuel Häuser,
• Klaus Langer and
• Monika Schönhoff

Beilstein J. Nanotechnol. 2015, 6, 2504–2512, doi:10.3762/bjnano.6.260

• taken up by endocytosis. During the process of endocytosis, nanoparticular drug carriers most often end up in endolysosomes with a reduced internal pH value. In order to provide improved accessibility of the drug to the whole cell, membrane destruction of the endolysosomal bilayer would be beneficial

Mapping bound plasmon propagation on a nanoscale stripe waveguide using quantum dots: influence of spacer layer thickness

• Chamanei S. Perera,
• Alison M. Funston,
• Han-Hao Cheng and
• Kristy C. Vernon

Beilstein J. Nanotechnol. 2015, 6, 2046–2051, doi:10.3762/bjnano.6.208

• , 750 nm wide with grating using electron beam lithography (EBL). Bilayer PMMA (950k A4 and 495k A4 PMMA from Microchem GmbH) was patterned using EBL and then developed for 30 seconds in MIBK:IPA developer solution. A silver film with 30 nm thickness was evaporated onto the resist using PVD 75 electron

• beam evaporator under 0.1 Å/s. Lift-off of the resist was achieved in an acetone bath. Stripes with length 20 µm were fabricated (Figure 2). When using bilayer PMMA in EBL, the substrate must be relatively conductive. We used ITO-coated glass substrate as a conductive substrate. The presence of the ITO

Distribution of Pd clusters on ultrathin, epitaxial TiO_x films on Pt₃Ti(111)

• Christian Breinlich,
• Maria Buchholz,
• Marco Moors,
• Tobias Pertram,
• Conrad Becker and
• Klaus Wandelt

Beilstein J. Nanotechnol. 2015, 6, 2007–2014, doi:10.3762/bjnano.6.204

• obtained on the Pt3Ti(111) surface exhibits characteristic stripes of densely packed, Ti–O rows of bilayer thickness. These are separated 1.44 nm apart from each other with parallel trenches in between. The w'-TiOx phase consists of a hexagonal, oxygen-terminated, Ti–O bilayer, which shows similarities to

• photoelectron spectroscopy (XPS) measurements indicated the existence of an oxygen-terminated Ti–O bilayer [6][7]. Depending on the applied oxygen dose, the z'-TiOx phase covers different fractions of the crystal surface, ranging from small separated islands up to a nearly complete film covering the whole

• '-TiOx phase is the second stable titanium oxide phase that can be grown on the Pt3Ti(111) surface with oxygen doses higher than 200 L within a temperature window of 800–1100 K [6]. HREELS and XPS studies also indicated a Ti–O bilayer structure with oxygen termination as a basic structure element for

Enhancing the thermoelectric figure of merit in engineered graphene nanoribbons

• Hatef Sadeghi,
• Sara Sangtarash and
• Colin J. Lambert

Beilstein J. Nanotechnol. 2015, 6, 1176–1182, doi:10.3762/bjnano.6.119

• . In monolayer graphene, this increases the electronic thermoelectric figure of merit ZTe from 0.01 to 0.5. The largest values of ZTe are found when a nanopore is introduced into bilayer graphene, such that the current flows from one layer to the other via the inner surface of the pore, for which

• ) in low dimensional materials [8]. In what follows we apply this approach to engineered graphene nanoribbons [9][10] and show that introducing nanopores into bilayer graphene [11], a room-temperature ZTe higher than 2 could be achieved. Computational methods The electrical conductance G(T), the

• investigating the thermoelectric properties of various forms of engineered graphene, obtained by sculpting nanopores in bilayer graphene and allowing the pore surface to reconstruct [9]. Pores in bilayer graphene are not only more stable than anti-dots in monolayer graphene, but should also be effective in

Pulmonary surfactant augments cytotoxicity of silica nanoparticles: Studies on an in vitro air–blood barrier model

• Jennifer Y. Kasper,
• Lisa Feiden,
• Maria I. Hermanns,
• Christoph Bantz,
• Michael Maskos,
• Ronald E. Unger and
• C. James Kirkpatrick

Beilstein J. Nanotechnol. 2015, 6, 517–528, doi:10.3762/bjnano.6.54

• (aSNPs) that they will be entirely coated with a phospholipid bilayer [7]. Consequently, an impaired cytotoxicity and transport/translocation to other organs may be perceived due to this surfactant coating. Several in vitro studies on aSNP toxicity have already been conducted using simple as well as