Highly sensitive detection of estradiol by a SERS sensor based on TiO₂ covered with gold nanoparticles

• Andrea Brognara,
• Ili F. Mohamad Ali Nasri,
• Beatrice R. Bricchi,
• Andrea Li Bassi,
• Caroline Gauchotte-Lindsay,
• Matteo Ghidelli and
• Nathalie Lidgi-Guigui

Beilstein J. Nanotechnol. 2020, 11, 1026–1035, doi:10.3762/bjnano.11.87

• previously isolated by the SELEX process by Kim and co-workers [17]. It was purchased from Eurogenetec with the following 76-mer-long sequence SH-C6-5′-GCT-TCC-AGC-TTA-TTG-AAT-TAC-ACG-CAG-AGG-GTA-GCG-GCT-CTG-CGC-ATT-CAA-TTG-CTG-CGC-GCT-GAA-GCG-CGG-AAG-C-3′. The thiol group was added to the 5′ end of the

• aptamer for functionalization via a Au–S bond. The aptamer was diluted and aliquoted upon arrival and stored at −18 °C. Sample functionalization MBA was used as a common Raman reporter to find out the best deposition parameters for Raman scattering enhancement. The thiol group is known to have a strong

• substrates, MBA was used as it is a well-known Raman reporter, showing two intense characteristic peaks at 1080 and 1590 cm−1 from aromatic ring vibrations [30]. The structure of MBA and the grafting process (thiol–gold interaction) guarantee that the molecule will preferentially attach to gold [37][38]. The

Silver-decorated gel-shell nanobeads: physicochemical characterization and evaluation of antibacterial properties

• Marta Bartel,
• Katarzyna Markowska,
• Marcin Strawski,
• Krystyna Wolska and
• Maciej Mazur

Beilstein J. Nanotechnol. 2020, 11, 620–630, doi:10.3762/bjnano.11.49

• layer producing silver nanoparticles but also transforms a fraction of sulfonic groups in the polymer to moieties with sulfur in a lower oxidation state, likely thiols. It is hypothesized that the generated thiol groups are anchoring the nanoparticles in the gel shell of the nanobeads stabilizing the

• have been partially reduced to thiol moieties. In consequence, the thiols interact with the silver nanoparticles anchoring them in the gel layer on the nanobeads. Moreover, it has been shown that the nanocomposite exhibits considerable antibacterial activity, comparable or superior to that of non

• reduced to a thiol moiety [37]. If this is the case, it may be hypothesized that the generated thiols adsorb on the surface of the silver nanoparticles (the adsorption of thiols on silver surfaces is a well-known phenomenon). It should be noted, however, that the binding energy of sulfur in aromatic

Luminescent gold nanoclusters for bioimaging applications

• Nonappa

Beilstein J. Nanotechnol. 2020, 11, 533–546, doi:10.3762/bjnano.11.42

• , semiconductor quantum dots suffer from toxicity and are susceptible to oxidation. In this context, atomically precise gold nanoclusters protected by thiol monolayers have emerged as a new class of luminescent nanomaterials. Low toxicity, bioavailability, photostability as well as tunable size, composition, and

• play an important role in the luminesce properties of NCs [48][55]. For example, a phenylethane thiol (PET)-capped organically soluble Au25 nanocluster (Au25PET18) showed similar behavior as Au25NCs capped with long-chain alkanes [59]. However, it was shown that by choosing the appropriate surface

• of gold nanoclusters. A) Nanoclusters provide a link between molecular complexes and plasmonic nanoparticles. B) X-ray structure of [Au25(PET)18], from CSD entry JACVOB. C) Chemical structure of some of the organic thiols discussed in this review (PET: phenylethane thiol; LA: lipoic acid; GSH

Multilayer capsules made of weak polyelectrolytes: a review on the preparation, functionalization and applications in drug delivery

• Varsha Sharma and
• Anandhakumar Sundaramurthy

Beilstein J. Nanotechnol. 2020, 11, 508–532, doi:10.3762/bjnano.11.41

• ), is a reversible reaction between different types of diene and dienophile resulting in thermo-responsive products. A fourth type, the thiol-ene reaction, is a reaction between thiol and alkene groups in the presence of a radical source as catalyst. The radicals can be generated through light, thermal

• . Other click chemistries like thiol-ene have also been reported because of their light-initiated and metal-catalyst-free approach. PVP along with PMA functionalized by thiol (PMAThiol) and ene (PMAEne) groups were used to fabricate hydrogen bonded hollow capsules via UV crosslinking [100]. It was further

• use of UV light in the thiol-ene approach limits its application in drug delivery as it can damage DNA and cross-react with cysteine residues in proteins. The DAC approach may also affect cysteine residues in proteins that might undergo Michael addition to result in malemides [90]. Similarly, the use

Preparation and in vivo evaluation of glyco-gold nanoparticles carrying synthetic mycobacterial hexaarabinofuranoside

• Gennady L. Burygin,
• Polina I. Abronina,
• Nikita M. Podvalnyy,
• Sergey A. Staroverov,
• Leonid O. Kononov and
• Lev A. Dykman

Beilstein J. Nanotechnol. 2020, 11, 480–493, doi:10.3762/bjnano.11.39

• the antibodies generated against Ara6-GNPs would recognize the natural saccharides on the cell surface of different mycobacterial strains. For the preparation of glyco-GNPs, glycans are usually transformed to glycosides with thiol-functionalized spacer aglycons that are conjugated [43][44] either with

• pre-formed citrate-stabilized GNPs [67] or during the in situ synthesis of glyco-GNPs [32][38][46]. It is also possible to conjugate suitably derivatized glycans [48] via additional functional groups of thiol-functionalized ligands attached to the surface of pre-formed GNPs. We, however, chose an

• penetrate into the cells and can be used as carriers [83]. It has been demonstrated that the amine–gold surface interaction is charge-neutral and the stability of amine-capped GNPs is a finite-size effect, which is largely kinetic in origin, unlike that of thiol-capped GNPs, which are known to possess

Internalization mechanisms of cell-penetrating peptides

• Ivana Ruseska and
• Andreas Zimmer

Beilstein J. Nanotechnol. 2020, 11, 101–123, doi:10.3762/bjnano.11.10

• -siRNA/miRNA delivery [17]. It has been reported that CPP-siRNA conjugates have reduced transient and stable expression of reporter transgenes in a number of mammalian cell lines [18]. In this case, thiol-containing siRNAs were synthesized and conjugated to penetratin or transportan by a reducible

Fully amino acid-based hydrogel as potential scaffold for cell culturing and drug delivery

• Dávid Juriga,
• Evelin Sipos,
• Orsolya Hegedűs,
• Gábor Varga,
• Miklós Zrínyi,
• Krisztina S. Nagy and
• Angéla Jedlovszky-Hajdú

Beilstein J. Nanotechnol. 2019, 10, 2579–2593, doi:10.3762/bjnano.10.249

• concentration of the elastically active chain were determined. After reduction of the disulfide bonds of CYS, the presence of thiol side groups was also detected. To determine the concentration of the reactive cross-linkers in the hydrogels, a new method based on the examination of the swelling behavior was

• established. Using metoprolol as a model drug, cell proliferation and drug release kinetics were studied at different LYS contents and in the presence of thiol groups. The optimal ratio of cross-linkers for the proliferation of periodontal ligament cells was found to be 60−80% LYS and 20−40% CYS. The

• untransformed cells. In the present study, derivatives based exclusively on amino acids, namely, on lysine-methylester (LYS) and CYS, were used as cross-linkers for preparing PASP-based hydrogels. CYS is biologically active and can provide free thiol groups under reductive conditions, while the advantage of LYS

Long-term stability and scale-up of noncovalently bound gold nanoparticle-siRNA suspensions

• Anna V. Epanchintseva,
• Julia E. Poletaeva,
• Dmitrii V. Pyshnyi,
• Elena I. Ryabchikova and
• Inna A. Pyshnaya

Beilstein J. Nanotechnol. 2019, 10, 2568–2578, doi:10.3762/bjnano.10.248

• structures usually consists of a AuNP, where siRNA is covalently bound to the NP surface through the thiol group, and the core is covered with a lipid or polymer shell [10][11][12][13]. Covalent bonding of siRNA to the surface of AuNPs is carried out in two stages: (1) covalent attachment of one chain of a

Bombesin receptor-targeted liposomes for enhanced delivery to lung cancer cells

• Mohammad J. Akbar,
• Pâmela C. Lukasewicz Ferreira,
• Melania Giorgetti,
• Leanne Stokes and
• Christopher J. Morris

Beilstein J. Nanotechnol. 2019, 10, 2553–2562, doi:10.3762/bjnano.10.246

• manner – a key feature of a targeting ligand to enable high tumour localisation. Formulation of a GRP-targeted liposomal carrier Having validated GRPR as a functional target on the surface of SCLC cells we next prepared a targeted liposomal carrier. The presence of a single thiol group in the cystabn

• peptide affords facile functionalisation of DSPE-PEG2000-maleimide thorough thiol coupling chemistry. Successful conjugation of the peptide was confirmed by MALDI–TOF mass spectrometry (Figure 2a,b). The most abundant mass peak of DSPE-PEG2000-cystabn (calculated mass: 4137.41 Da, assuming perfect

Evaluation of click chemistry microarrays for immunosensing of alpha-fetoprotein (AFP)

• Seyed Mohammad Mahdi Dadfar,
• Sylwia Sekula-Neuner,
• Vanessa Trouillet,
• Hui-Yu Liu,
• Ravi Kumar,
• Annie K. Powell and
• Michael Hirtz

Beilstein J. Nanotechnol. 2019, 10, 2505–2515, doi:10.3762/bjnano.10.241

• sensitive fluorescent immunosensor for AFP detection. Three types of functionalized glasses (dibenzocyclooctyne- (DBCO-), thiol- and epoxy-terminated surfaces) were biotinylated by employing the respective adequate click chemistry counterparts (biotin–thiol or biotin–azide for the first class, biotin

• –maleimide or biotin–DBCO for the second class and biotin–amine or biotin–thiol for the third class). The anti-AFP antibody was immobilized on the surfaces via a biotin–streptavidin–biotin sandwich technique. To evaluate the sensing performance of the differently prepared surfaces, fluorescently labeled AFP

• –biotin sandwich strategy as well as the high selectivity of antigen–antibody interactions. Six different fabrication routes based on dibenzocyclooctyne- (DBCO-), thiol- and epoxy-functionalization of glasses and click chemistry attachment of biotinylated molecules (Figure 1) were used to obtain

Mobility of charge carriers in self-assembled monolayers

• Zhihua Fu,
• Tatjana Ladnorg,
• Hartmut Gliemann,
• Alexander Welle,
• Asif Bashir,
• Michael Rohwerder,
• Qiang Zhang,
• Björn Schüpbach,
• Andreas Terfort and
• Christof Wöll

Beilstein J. Nanotechnol. 2019, 10, 2449–2458, doi:10.3762/bjnano.10.235

• of charge carriers has been observed in field-effect transistors (FET) made from this compound [32]. Anthracene-2-thiol, obtained by functionalization of anthracene with a thiol group, was used to fabricate SAMs on the top of Au bottom electrodes, which resulted in a beneficial effect on the

• thiol, we used the nanografting technique introduced by G.-y. Liu et al. [37]. HDT was used as the insulating thiol to decouple the PAT islands. Starting from a high quality PAT SAM, in well-defined PAT areas the OSC-based thiol was replaced by HDT using nanografting carried out in a liquid cell of an

• a function of island diameter. The black line shows the result of a fit in the diameter interval 20–160 nm by using Equation 1. a) Simple model of resistance within a single thiol molecule on the gold(111) surface. b) Model of charge transfer within a continuous SAM. The number of parallel resistors

Multiwalled carbon nanotube based aromatic volatile organic compound sensor: sensitivity enhancement through 1-hexadecanethiol functionalisation

• Nadra Bohli,
• Meryem Belkilani,
• Juan Casanova-Chafer,
• Eduard Llobet and
• Adnane Abdelghani

Beilstein J. Nanotechnol. 2019, 10, 2364–2373, doi:10.3762/bjnano.10.227

• temperature toluene and benzene sensor based on multiwall carbon nanotubes (MWCNTs) decorated with gold nanoparticles and functionalised with a long-chain thiol self-assembled monolayer, 1-hexadecanethiol (HDT). High-resolution transmission electron microscopy (HRTEM) and Fourier transform infrared

• spectroscopy (FTIR) were performed to characterize the gold nanoparticle decoration and to examine the thiol monolayer bonding to the MWCNTs. The detection of aromatic vapours using Au-MWCNT and HDT/Au-MWCNT sensors down to the ppm range shows that the presence of the self-assembled layer increases the

• -assembled monolayer of 1-hexadecanethiol (HDT). The sensor functionalisation was undertaken through its immersion for 4 hours at room temperature in a solution of 5 mM of HDT diluted in ethanol. The sensor was then rinsed with ethanol to wash off the unbound thiol molecules and dried under a nitrogen stream

Adsorption and desorption of self-assembled L-cysteine monolayers on nanoporous gold monitored by in situ resistometry

• Elisabeth Hengge,
• Eva-Maria Steyskal,
• Rupert Bachler,
• Alexander Dennig,
• Bernd Nidetzky and
• Roland Würschum

Beilstein J. Nanotechnol. 2019, 10, 2275–2279, doi:10.3762/bjnano.10.219

• using the well-known spontaneous formation of self-assembled monolayers (SAMs) on gold substrates [5]. These layers usually consist of three groups: a thiol as the head group, a carbon chain as the backbone and an end group that can be chosen according to the requirements for subsequent application. For

Toxicity and safety study of silver and gold nanoparticles functionalized with cysteine and glutathione

• Barbara Pem,
• Igor M. Pongrac,
• Lea Ulm,
• Ivan Pavičić,
• Valerije Vrček,
• Darija Domazet Jurašin,
• Marija Ljubojević,
• Adela Krivohlavek and
• Ivana Vinković Vrček

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

• Carol López de Dicastillo,
• Cristian Patiño,
• María José Galotto,
• Yesseny Vásquez-Martínez,
• Claudia Torrent,
• Daniela Alburquenque,
• Alejandro Pereira and
• Juan Escrig

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

• Stéphane Louisia,
• Yohann R. J. Thomas,
• Pierre Lecante,
• Marie Heitzmann,
• M. Rosa Axet,
• Pierre-André Jacques and
• Philippe Serp

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

• Zaid K. Alghrair,
• David G. Fernig and
• Bahram Ebrahimi

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

• Jad Sabek,
• Francisco Javier Díaz-Fernández,
• Luis Torrijos-Morán,
• Zeneida Díaz-Betancor,
• Ángel Maquieira,
• María-José Bañuls,
• Elena Pinilla-Cienfuegos and
• Jaime García-Rupérez

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

• Xiupei Yang,
• Zhengli Yang,
• Fenglin Tang,
• Jing Xu,
• Maoxue Zhang and
• Martin M. F. Choi

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

• Hrvoje Gebavi,
• Vlatko Gašparić,
• Dubravko Risović,
• Nikola Baran,
• Paweł Henryk Albrycht and
• Mile Ivanda

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

• Juan Casanova-Cháfer,
• Carla Bittencourt and
• Eduard Llobet

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

• Gonzalo Villaverde and
• Alejandro Baeza

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

• Pierre-Etienne Rouet,
• Cyril Chomette,
• Laurent Adumeau,
• Etienne Duguet and
• Serge Ravaine

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

• Hendrikje R. Neumann and
• Christine Selhuber-Unkel

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

• Janning F. Herrmann and
• Christiane Höppener

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