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Search for "thiol" in Full Text gives 172 result(s) in Beilstein Journal of Nanotechnology.
Toxicity and safety study of silver and gold nanoparticles functionalized with cysteine and glutathione
Beilstein J. Nanotechnol. 2019, 10, 1802–1817, doi:10.3762/bjnano.10.175
- lead to the formation of thiol-coated AgNPs [48]. New clusters consisting of Ag2S can be created from free Ag+ [47]. This process, known as sulfidation, affects AgNP behavior in the biological system [49], most notably by reducing their toxicity [47][50]. The binding of thiols to AuNP surfaces has been
- metallic NPs, was applied to evaluate small changes in the chemical environment around NPs, which resulted in chemical shifts in the NMR spectra. Several studies have been published that confirm the validity of this technique in confirming thiol–NP interactions [51][59][60][61]. In a typical experiment
Novel hollow titanium dioxide nanospheres with antimicrobial activity against resistant bacteria
Beilstein J. Nanotechnol. 2019, 10, 1716–1725, doi:10.3762/bjnano.10.167
- reactive oxygen species (ROS) generation and disruption of bacteria cell walls in the case of E. coli, and release and reactions of ions with thiol groups belonging to proteins of the bacterial membrane of S. aureus [48][49]. Probably, CSTiO2 presented better affinity and greater contact area with Gram
Alloyed Pt3M (M = Co, Ni) nanoparticles supported on S- and N-doped carbon nanotubes for the oxygen reduction reaction
Beilstein J. Nanotechnol. 2019, 10, 1251–1269, doi:10.3762/bjnano.10.125
- –C (≈163.5 eV), R–S–C (≈164.5 eV), and S–O (≈168.0 eV) were observed (Supporting Information File 1, Figure S3) [42][43]. The intense peak at 163.5 eV indicated the doping of CNTs with mainly thiol surface groups (Table 2). The peak at 164.5 eV could arise from the presence of sulfur in the carbon
Enhanced inhibition of influenza virus infection by peptide–noble-metal nanoparticle conjugates
Beilstein J. Nanotechnol. 2019, 10, 1038–1047, doi:10.3762/bjnano.10.104
- Sephadex G25, as they eluted in the void volume and their UV–vis spectrum in PBS was indistinguishable from that of control mixed-matrix silver nanoparticles (Figure 5A). When challenged by a small thiol, DTT, the silver nanoparticles passivated by the mixed-matrix ligand shell were somewhat more prone to
Experimental study of an evanescent-field biosensor based on 1D photonic bandgap structures
Beilstein J. Nanotechnol. 2019, 10, 967–974, doi:10.3762/bjnano.10.97
- biorecognition layer, we have developed a light-assisted biofunctionalization approach that allows for the covalent immobilization of thiol-terminated bioreceptors onto a vinyl-terminated surface [13]. Half-antiBSA-antibodies (haBSA) have been used as bioreceptors in this work, which reduces even more the
- represent the standard deviation of the intensity along the PBG structure. Schematic representation of the light-assisted immobilization of haBSA having free thiol moieties onto the vinyl-functionalized surface of the PBG sensing structures. Time evolution of the PBG sensing response during the BSA
Structural and optical properties of penicillamine-protected gold nanocluster fractions separated by sequential size-selective fractionation
Beilstein J. Nanotechnol. 2019, 10, 955–966, doi:10.3762/bjnano.10.96
- properties of AuNCs may be altered in the presence of excess thiol ligand; hence, it is necessary to develop a convenient, efficient, and stringent method for the purification of crude monolayer-protected NCs samples. The purification of AuNCs is a very challenging task due to the similar solubility of water
- that the AuNCs have an anisotropic crystalline structure. This result is similar to that obtained by Lakshminarayanan for the diffraction characteristic of 1–3 nm thiol-monolayer-protected clusters [21]. As for the fractions F72% and F90%, the {111} and {200} planes appear blurrier and the {220}, {311
- more positively charged than those of the former. Although there are only few reports of positively charged thiol-protected AuNCs, the chemical oxidation of [Au25(SC6H13)18]0 described in [33] yielded positively charged AuNCs. The Au 4f7/2 binding energy in the residue fraction (F0%), however, is
Features and advantages of flexible silicon nanowires for SERS applications
Beilstein J. Nanotechnol. 2019, 10, 725–734, doi:10.3762/bjnano.10.72
- temperature and thickness were reported in [26]. 4-MPBA was chosen as a SERS test molecule because of the strong affinity between the thiol group and metal surfaces (Ag or Au) as well as because of the easy formation of self-assembled monolayers (SAMs) [27]. Furthermore, the benzene ring is orientation
Hydrophilicity and carbon chain length effects on the gas sensing properties of chemoresistive, self-assembled monolayer carbon nanotube sensors
Beilstein J. Nanotechnol. 2019, 10, 565–577, doi:10.3762/bjnano.10.58
- attributed to the interaction, via strong hydrogen bonding, of the polar molecules tested to the polar surface of hydrophilic thiols. The approach discussed here could be extended further by combining hydrophilic and hydrophobic thiol SAMs in Au-MWCNT sensor arrays as a helpful strategy for tuning sensor
- ); self-assembled monolayer (SAM); thiol; Introduction Carbon nanotubes were first observed by Sumio Iijima in 1991 [1] and since then, this nanostructure has been widely used in chemoresistive gas sensors [2][3][4][5] due to the possibility to engineer its sensitivity towards chemicals present in a
- approach, carbon nanotubes act as support and charge transport transducing elements while the recognition function is performed by grafted molecules. Two examples of this have consisted of obtaining thiol-functionalized carbon nanotube buckypapers [27] or self-assembled monolayers (SAMs) of thiol molecules
Targeting strategies for improving the efficacy of nanomedicine in oncology
Beilstein J. Nanotechnol. 2019, 10, 168–181, doi:10.3762/bjnano.10.16
- techniques as carbodiimide coupling chemistry [28]. An alternative is the introduction of certain functional groups on specific positions of the antibody, which allows the utilization of bio-orthogonal chemical strategies, such as azide-strained alkyne or thiol–maleimide reaction, for carrying out the
- specifically designed for binding to the epidermal growth factor receptors (EGFR) have been anchored on the surface of hollow gold nanospheres [39]. The thiolated version of these aptamers was anchored on the gold surface through the thiol groups producing an average anchorage yield of 250 aptamers per
Colloidal chemistry with patchy silica nanoparticles
Beilstein J. Nanotechnol. 2018, 9, 2989–2998, doi:10.3762/bjnano.9.278
- , i.e., well-calibrated silica nanospheres or core–shell nanoparticles, were obtained according to a seeded-growth protocol [22] and a method using methoxy poly(ethylene glycol)-thiol as a coupling agent [23], respectively. Their surface functionalization with carboxylic acid groups was performed by a
High-throughput micro-nanostructuring by microdroplet inkjet printing
Beilstein J. Nanotechnol. 2018, 9, 2372–2380, doi:10.3762/bjnano.9.222
- [9], titania [10], and hybrid nanoparticles [11][12]. If the nanoparticles are intended to provide a chemical contrast for further functionalization, gold nanoparticles are an appropriate choice as they are easily functionalized using thiol chemistry [13]. For example, gold nanoparticles prepared by
Dumbbell gold nanoparticle dimer antennas with advanced optical properties
Beilstein J. Nanotechnol. 2018, 9, 2188–2197, doi:10.3762/bjnano.9.205
- . Utilizing the capabilities of an AFM to manipulate such structures with sub-nanometer precision in space enables to add a smaller 40 nm AuNP to the larger one. Even though, shorter linker thiol molecules could be used instead, in principle, the high mobility of these linker molecules on the AuNP surface
- expected cascade of the electromagnetic field towards the intermediate points of these gap structures. Figure 2D indicates that the CB[8] antenna provides similar light confinement capabilities than the thiol trimer. Most strikingly, the electromagnetic field enhancement of this dimer antenna reaches the
- a high reproducibility of these antennas and a low influence of deviations from the sphere geometry on the enhancement factor. The enhancement factor is further increased by utilizing the gap mode. In this case the average fluorescence enhancement factor for the thiol-mediated gap antennas is
Self-assembled quasi-hexagonal arrays of gold nanoparticles with small gaps for surface-enhanced Raman spectroscopy
Beilstein J. Nanotechnol. 2018, 9, 1977–1985, doi:10.3762/bjnano.9.188
- features. To measure the SERS signal, the gold nanoparticles were covered with a self-assembled monolayer of 4-MBA. Because the thiol-group of the 4-MBA molecules has a very high affinity for gold [27], and the samples were rinsed thoroughly with ethanol to remove any unbound molecules, we can assume that
Tuning adhesion forces between functionalized gold colloidal nanoparticles and silicon AFM tips: role of ligands and capillary forces
Beilstein J. Nanotechnol. 2018, 9, 660–670, doi:10.3762/bjnano.9.61
- ) equipped with PeakForce QNM (Quantitative Nanoscale Mechanics) module. Au NPs were synthesized by a seed-mediated process and then functionalized with thiols containing different functional groups: amino, hydroxy, methoxy, carboxy, methyl, and thiol. Adhesion measurements showed strong differences between
- (–COOH), methyl (–CH3), methoxy (–OCH3) or thiol (–SH). The adhesion was measured by atomic force microscope (AFM) equipped with a PeakForce QNM module. The results were also compared to additional adhesion measurements performed on flat Au films functionalized with the same molecular thin film to
- organosulfur (thiol) molecules having different tail groups ranging from a highly hydrophilic (–OH, –COOH, –SH, –NH2) to a partially hydrophilic (–O–CH3) and to a more hydrophobic group (–CH3). A covalent bond between the sulfur head group (–SH) and the Au atoms ensured the strong anchorage of the organosulfur
Facile phase transfer of gold nanorods and nanospheres stabilized with block copolymers
Beilstein J. Nanotechnol. 2018, 9, 616–627, doi:10.3762/bjnano.9.58
- the use of strong thiol and amine surfactants. Keywords: Au nanorods; block copolymers; optical absorbance spectroscopy; phase transfer; seeded growth method; Introduction The size effects that determine the functional characteristics of nanoparticles are no less important than their precise
- or cetyl trimethylammonium bromide-stabilized Au nanorods with a solution of thiol- [18] or amine-terminated [19] surfactants in organic solvent. With a strong affinity to gold, thiols and amines replace nanoparticle shells via ligand exchange, while the tails of these molecules provide miscibility
- propose that P2VP blocks wrap around nanoparticles preventing their aggregation, while PS blocks form an organophilic corona that provides dispersability of the nanoparticles in organic media. Compared to thiol- and amine-functionalized stabilizers that form strong covalent bonds with Au, the interaction
Wafer-scale bioactive substrate patterning by chemical lift-off lithography
Beilstein J. Nanotechnol. 2018, 9, 311–320, doi:10.3762/bjnano.9.31
- -arrangement of silane or thiol molecules on silica or Au surfaces, which has been proven as a convenient route for the fabrication of functional surfaces toward versatile targets [12][13][14][15][16]. In addition to direct surface modification, the versatility of anchoring molecule tail groups provides
- washed with ethanol to remove excess thiol molecules, and blown dry with nitrogen gas. Polydimethylsiloxane (PDMS) stamps with various patterns were fabricated by standard photolithography-created masters. A 10:1 mass ratio of SYLGARD 184 silicone elastomer base and curing agent (Dow Corning, Midland, MI
- TRIS buffer (150 mM NaCl, pH 7.4) in advance. Target DNA solutions in 25 mM TRIS buffer (150 mM NaCl, pH 7.4) was thereafter dropped onto the target DNA-specific probe-modified substrates for a 5 min incubation period. For sandwich-like array signal reporting, biotinylated thiol-patterned substrates
Patterning of supported gold monolayers via chemical lift-off lithography
Beilstein J. Nanotechnol. 2017, 8, 2648–2661, doi:10.3762/bjnano.8.265
- found to be consistent with molecular dynamics simulations that predicted the removal of no more than 1.5 Au atoms per thiol, thus presenting a monolayer-like structure. Keywords: chemical patterning; hybrid material; monolayer; soft lithography; two-dimensional material; Introduction Chemical lift
- orientation and each thiol removes one Au atom. Nonetheless, we know that the Au–alkanethiolate monolayers on PDMS resulting from typical CLL experiments are indicative of incomplete lift-off [1][10][31]. Moreover, the dimensions of the Au–alkanethiol complexes that compose the lifted-off monolayer on PDMS
- structures that are still able to bond to additional Au atoms. Before complete separation, a chain consisting of two or three Au atoms between each thiol and the Au surface is formed and finally ruptures, usually after the first or second Au atom has attached to each sulfur atom. As a consequence of lift-off
The role of ligands in coinage-metal nanoparticles for electronics
Beilstein J. Nanotechnol. 2017, 8, 2625–2639, doi:10.3762/bjnano.8.263
- substituents (Me, MeO, Cl, or Br) in para-position to the thiol group reduced the conductivity compared to films of triphenylphosphine (PPh3) (Figure 3) and thiophenol (H)-capped gold nanocrystals. The electron-withdrawing nitro group (NO2) caused an increase in conductivity from 30 S/cm (PPh3-capped Au NPs
- transformation temperatures (Tp) are desirable for applications on plastic films with low glass-transition temperatures (Tg) [33][44]. The required annealing temperature is correlated with the length of the capping agents as reported by Gupta and co-workers. Inks of thiol-functionalized gold nanoparticles having
- thiols with eight, six, or four carbon atoms in their alkyl chains exhibited descending sintering temperatures from the longer thiol (204 °C) to the shorter (155 °C). The layer prepared from the C4-thiol-functionalized gold nanoparticles could be annealed at 160 °C, a temperature sufficiently low to
Inelastic electron tunneling spectroscopy of difurylethene-based photochromic single-molecule junctions
Beilstein J. Nanotechnol. 2017, 8, 2606–2614, doi:10.3762/bjnano.8.261
- switched to either the open or the closed form in ethanol and are subsequently assembled on gold-patterned MCBJ samples [14]. The acetyl (COCH3, denoted as Ac) groups are cleaved off by adding a droplet of ammonium hydroxide (NH4OH), resulting in a thiol (SH) group, before assembly on the metal surfaces of
- C5F-ThM molecules [14]. The overall magnitude of the conductance of both the open and the closed form is rather small. This can be attributed to the presence of sp3 hybridized methylene groups, isolating the π-system and the thiol anchor groups. These act as efficient tunneling barriers for the
Amplified cross-linking efficiency of self-assembled monolayers through targeted dissociative electron attachment for the production of carbon nanomembranes
Beilstein J. Nanotechnol. 2017, 8, 2562–2571, doi:10.3762/bjnano.8.256
- -biphenyls, where the DEA channel is exothermic, we expect significant cross sections at 0 eV. Similarly, from the DEA threshold energy, we expect C–H cleavage through DEA to be present but inefficient. In fact, Houplin et al. [32] recently showed that for terphenyl-thiol (TPT) SAMs, which should behave
- . In a control experiment, DEA to 2-bromobiphenyl-4-thiol was also studied. The effect of the 4-thiol group was found to be insignificant. For comparison, we have recorded positive ion mass spectra at 70 eV (not shown here), and we find that these agree well with those available in the NIST database
- that the radical sites generated in the DEA process substantially stimulate the cross-linking process and that the very effective iodine loss in the DEA process should thus be reflected in the cross-linking efficiency. The decrease of the intensity maximum of the thiol sulfur S 2p3/2 peak at a binding
Synthesis of metal-fluoride nanoparticles supported on thermally reduced graphite oxide
Beilstein J. Nanotechnol. 2017, 8, 2474–2483, doi:10.3762/bjnano.8.247
- Scheme S2 in Supporting Information File 1). Thiol-functionalized TRGO-SH [62] was additionally used to support metal-fluoride nanoparticles. The morphology, crystalline phase (MFx-NPs), size and size dispersion of the nanoparticles was analyzed by powder X-ray diffraction (PXRD) and transmission
Expanding the molecular-ruler process through vapor deposition of hexadecanethiol
Beilstein J. Nanotechnol. 2017, 8, 2339–2344, doi:10.3762/bjnano.8.233
- iterative deposition of bifunctional organic molecules and metal ions. Note that the use of a thiol as one of the two functionalities ensures that deposition and growth of the multilayer only occurs on the surface of the metal, not the exposed substrate. By using molecules of discrete length, the thickness
- apply this strategy to other bifunctional thiol molecules are ongoing. Key steps for the molecular-ruler process. (A) A metal is patterned on a substrate via conventional lithography. (B) A molecular-ruler, consisting of alternating layers of thiol molecules and metal ions, is created only on the first
Application of visible-light photosensitization to form alkyl-radical-derived thin films on gold
Beilstein J. Nanotechnol. 2017, 8, 1863–1877, doi:10.3762/bjnano.8.187
- cursor profiles and for a head-to-head comparison of the chemical and mechanical stability of a polynitrophenylene multilayer to a thiol thin film on Au(111) [17]. In the work described herein, visible-light-photosensitized deposition of alkyl radicals was combined with particle lithography to generate
- radical contains a 10 carbon chain which has a theoretical chain length of 1.5 nm, however, the observed film thickness is probably coincidental. It is likely that the upright conformations and surface assembly seen with thiol SAMs [55][56][57][58] is not operative with our method, and water contact
- force applied by an AFM tip readily removed ω-functionalized thiol SAMS from Au [59] whereas 10 nN could not remove Au–Me or Au–NHBoc films. In considering the process 11→12 (Scheme 3), the rate of hydrogen atom abstraction by a primary, carbon-centered radical from a relatively strong bond between an
A biofunctionalizable ink platform composed of catechol-modified chitosan and reduced graphene oxide/platinum nanocomposite
Beilstein J. Nanotechnol. 2017, 8, 1508–1514, doi:10.3762/bjnano.8.151
- . Printed patterns utilizing ink prepared with thiol-modified chitosan instead or no chitosan, just rGO–Pt dispersed in EG, were washed off during the course of the functionalization/hybridization process. Importantly, we observed no strong non-specific binding between the non-complementary PCR product and
Deposition of exchange-coupled dinickel complexes on gold substrates utilizing ambidentate mercapto-carboxylato ligands
Beilstein J. Nanotechnol. 2017, 8, 1375–1387, doi:10.3762/bjnano.8.139
- (Scheme 1), L’ an ambidentate coligand, and M is a paramagnetic transition metal ion, usually MnII, FeII, CoII, or NiII [37]. The ambidentate phosphane-carboxylato [38] and thiol-carboxylato coligands H2L2 and H1L3 (Figure 1) were found to bind selectively via their carboxylate function to form the
- carboxylato-bridged complexes [Ni2L(HL2)](ClO4) (2) and [Ni2L(L3)](ClO4) (3) [39][40] such that an exposed thiol or phosphane group is available for further functionalization. Indeed, 2 dimerizes via a disulphide bond upon oxidation in air to generate a tetranuclear [{Ni2L}2(O2CC6H4S)2]2+ complex, while
- according to a protocol developed for the preparation of self-assembled thiol monolayers [59] as the complexes cannot be deposited via the gas phase. They decompose without melting. Thus, clean gold-coated Si wafers were immersed in a 1 × 10−3 M solution of the respective complex in MeCN or CH2Cl2 for 24 h
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