Photoactive nanoarchitectures based on clays incorporating TiO₂ and ZnO nanoparticles

• Eduardo Ruiz-Hitzky,
• Pilar Aranda,
• Marwa Akkari,
• Nithima Khaorapapong and
• Makoto Ogawa

Beilstein J. Nanotechnol. 2019, 10, 1140–1156, doi:10.3762/bjnano.10.114

• represents an additional improvement of the photoactivity tuning of semiconductor–clay nanoarchitectures. For instance, tris(2,2′-bipyridine)ruthenium(II) has been used as photosensitizer for titania, being further applied to TiO2@clay nanoarchitectures. In this way, a synthetic saponite containing tris(2,2

• ′-bipyridine)ruthenium(II) intercalated in the interlayer space was complexed with TiO2 NPs [166]. The resulting material shows enhanced stability toward visible-light irradiation, if compared with the TiO2 (P25) standard material photosensitized by an analogous commercially available photosensitizer (tris(2,2

• ′ -bipyridine-4,4′-dicarboxylic acid)ruthenium(II) dichloride, abbreviated as Ru470). The stability of the two samples was compared by measuring the color change after visible-light irradiation from a solar simulator. The colour of the clay nanoarchitecture (hereafter abbreviated as [Ru(bpy)3]2+–TiO2@clay) did

Magnetic and luminescent coordination networks based on imidazolium salts and lanthanides for sensitive ratiometric thermometry

• Pierre Farger,
• Cédric Leuvrey,
• Mathieu Gallart,
• Pierre Gilliot,
• Guillaume Rogez,
• João Rocha,
• Duarte Ananias,
• Pierre Rabu and
• Emilie Delahaye

Beilstein J. Nanotechnol. 2018, 9, 2775–2787, doi:10.3762/bjnano.9.259

• in the physiological range. Indeed, to the best of our knowledge, only eight such visible luminescent ratiometric LnMOF thermometers have been reported [64][65][66][67][68][69][70][71], among which two outperform our material [Tb0.97Eu0.03(L)(ox)(H2O)]: Tb0.995Eu0.005@In(OH)(2,2′-bipyridine-5,5

• ′-dicarboxylate) with Sm = 4.47%·K−1 at 333 K [65] and Eu@UiO-(2,2′-bipyridine-5,5′-dicarboxylate) with Sm = 2.19%·K−1 at 293 K [67] (value recalculated and corrected using the published calibration curve). Two other thermometers have a performance similar to ours, Eu0.089Tb0.9911[2,6-di(2′,4′-dicarboxylphenyl

SERS active Ag–SiO₂ nanoparticles obtained by laser ablation of silver in colloidal silica

• Cristina Gellini,
• Francesco Muniz-Miranda,
• Alfonso Pedone and
• Maurizio Muniz-Miranda

Beilstein J. Nanotechnol. 2018, 9, 2396–2404, doi:10.3762/bjnano.9.224

• examined by UV–vis absorption spectroscopy, transmission electron microscopy and Raman spectroscopy. The surface enhanced Raman scattering (SERS) activity of these nanocomposites was tested using 2,2’-bipyridine as a molecular reporter and excitation in the visible and near-IR spectral regions. The

• computational DFT approach provided evidence of ligand adsorption on positively charged adatoms of the silver nanostructured surface, in a very similar way to the metal/molecule interaction occurring in the corresponding Ag(I) coordination compound. Keywords: 2,2’-bipyridine; DFT; laser ablation; silica

• and transmission electron microscopy (TEM). The SERS efficiency was tested by adsorption of 2,2'-bipyridine as a molecular reporter, whose SERS spectrum was interpreted by DFT, in order to gain information on the adsorbate and the interaction of the molecule with the metal surface. To our knowledge

Anchoring of a dye precursor on NiO(001) studied by non-contact atomic force microscopy

• Sara Freund,
• Antoine Hinaut,
• Nathalie Marinakis,
• Edwin C. Constable,
• Ernst Meyer,
• Catherine E. Housecroft and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2018, 9, 242–249, doi:10.3762/bjnano.9.26

• 2,2′-bipyridine (bpy). In a second step, the ligand-functionalized surface is either directly exposed to a homoleptic metal (typically copper) complex to undergo a ligand-exchange reaction to assemble a surface-bound heteroleptic dye, or is first capped with a metal ion followed by the ancillary

• ligand to complete the active dye [43][44][45]. We present in this paper, high-resolution structural and electrical measurements obtained by nc-AFM of a typical anchoring ligand (DCPDMbpy), based on a 6,6′-dimethyl-2,2′-bipyridine metal-binding domain with two 4-carboxyphenyl anchoring groups (see Figure

• in frequency-modulation mode using an electrical oscillation at a frequency of fac = 900 Hz and with an amplitude Vac = 800 mV applied together with the DC compensation voltage to the sample. Structure of 4,4′-di(4-carboxyphenyl)-6,6′-dimethyl-2,2′-bipyridine. The trans-conformation of DCPDMbpy (left

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

• Anastassia Kanavarioti Yenos Analytical LLC, El Dorado Hills, CA, USA 10.3762/bjnano.7.135 Abstract Osmium tetroxide 2,2’-bipyridine (OsBp) is known to react with pyrimidines in ssDNA and preferentially label deoxythymine (T) over deoxycytosine (C). The product, osmylated DNA, was proposed as a

• it was found that one of the contrast agents, a 1:1 mixture of osmium tetroxide and 2,2’-bipyridine, exhibited extraordinary properties, and was considered to be the “perfect” label (Scheme 1). These attributes are (i) room temperature reactivity at mM concentration, (ii) no loss of label upon

• are listed in Table 1. Preparation of OsBp stock solutions and protocols for osmylation reactions Typically, 1:1 mixtures of OsO4 and 2,2’-bipyridine were prepared. A stock solution of OsBp at 15.75 mM OsO4 was prepared by mixing a 2 mL 4% OsO4 (ampule) with 18 mL of water that contained the

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

• surrogate for nanopore-based sequencing. Osmylation is the addition of osmium tetroxide 2,2’-bipyridine (OsBp) to the C5–C6 pyrimidine double bond. The process is simple, selective for deoxythymidine (dT) over deoxycytidine (dC), unreactive towards the purines, practically 100% effective, and strikingly

• tetroxide solution (0.1575 M in ampules at 2 mL each) was purchased from Electron Microscopy Sciences. 2,2’-Bipyridine 99+% (bipyridine) was purchased from Acros Organics. Oligos were purchased from Integrated DNA Technologies (IDT), diluted with DNase/RNase-free water (from MP Biomedical) to 2 μg/mL or 100

• new OsBp preparation is still 15.75 mM in OsO4, just as in the old protocols [42][46], but prepared in saturated 2,2’-bipyridine using a 4 to 8-fold molar excess of the later. After vigorous mixing of the two components, the supernatant is removed and used as the new stock solution (OsBp 15.75 mM in

Silica micro/nanospheres for theranostics: from bimodal MRI and fluorescent imaging probes to cancer therapy

• Shanka Walia and
• Amitabha Acharya

Beilstein J. Nanotechnol. 2015, 6, 546–558, doi:10.3762/bjnano.6.57

• NPs for biomedical applications. The synthesis was achieved by using iron oxide NPs, SiO2, lanthanide (Ln) salts (Eu, Tb) and 2,2'-bipyridine-4,4'-dicarboxylic acid (BDA), which acts as organic linker for binding Ln ions to the silica surface containing magnetic NPs. The average diameter of the

Hybrid spin-crossover nanostructures

• Carlos M. Quintero,
• Gautier Félix,
• Iurii Suleimanov,
• José Sánchez Costa,
• Gábor Molnár,
• Lionel Salmon,
• William Nicolazzi and
• Azzedine Bousseksou

Beilstein J. Nanotechnol. 2014, 5, 2230–2239, doi:10.3762/bjnano.5.232

• state was preprogrammed into these substrates by scanning a probe (±900 V) before deposition of a SCO layer. The complex [Fe(H2B(pz)2(bipy)] (pz = pyrazol-1-yl, bipy = 2,2’-bipyridine) was sublimated onto these substrates to form different thin films of 10 to 25 molecular layers in thickness and also

Non-covalent and reversible functionalization of carbon nanotubes

• Antonello Di Crescenzo,
• Valeria Ettorre and
• Antonella Fontana

Beilstein J. Nanotechnol. 2014, 5, 1675–1690, doi:10.3762/bjnano.5.178

• polyfluorene derivatives have been recently used for dispersing SWCNTs into different organic solvents. Poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt-co-(6,6’-{2,2’-bipyridine})] (PFO-BPy, see Table 1) has been demonstrated [54] to selectively wrap highly semiconducting SWCNT species with large diameters ranging

• ascorbic acid to a chloroform solution of SWCNT coated with a Cu(II) complex, in which the 2,2’-bipyridine derivative ligand bears two cholesteryl groups, induces the precipitation of the nanotubes due to the formation of the reduced Cu(I) complex [102]. The conformational change from the planar structure

Kelvin probe force microscopy of nanocrystalline TiO₂ photoelectrodes

• Alex Henning,
• Gino Günzburger,
• Res Jöhr,
• Yossi Rosenwaks,
• Biljana Bozic-Weber,
• Catherine E. Housecroft,
• Edwin C. Constable,
• Ernst Meyer and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2013, 4, 418–428, doi:10.3762/bjnano.4.49

• -thienyl)-2,2′-bipyridine)2]+ [43]. In order to remove weakly adsorbed contaminants, the sensitized TiO2 was rinsed with ethanol and dried under nitrogen. Kelvin probe force microscopy AFM measurements were carried out inside a glove box (labmaster 130, mBraun) maintaining a dry nitrogen atmosphere (<1 ppm

Septipyridines as conformationally controlled substitutes for inaccessible bis(terpyridine)-derived oligopyridines in two-dimensional self-assembly

• Daniel Caterbow,
• Daniela Künzel,
• Michael G. Mavros,
• Axel Groß,
• Katharina Landfester and
• Ulrich Ziener

Beilstein J. Nanotechnol. 2011, 2, 405–415, doi:10.3762/bjnano.2.46

• remaining four members of the series are synthetically inaccessible. The self-assembling properties of three of the missing four BTP isomers can be mimicked by making use of the energetically preferred N–C–C–N transoid conformation between 2,2'-bipyridine subunits in a new class of so-called septipyridines

• structures [23][24][25], and sometimes extrinsic factors, such as the presence of guest molecules [26][27], or the pH value [28][29], trigger the formation of certain self-assembled conformers. It is known that for 2,2'-bipyridine, the transoid conformation of the N–C–C–N unit is preferred because of dipole

• pyridine units, similarly known for 2,2'-bipyridine [30]. If the core unit of the BTPs is exchanged for a pyridine moiety, the opposite conformation should be preferably formed. Finally, the corresponding phenylseptipyridines prepared from the available 2,4'-, 2,3'-, 2,2'-, 3,3'-, and 4,3'-diazachalcones