Fast surface immobilization of native proteins through catalyst-free amino-yne click bioconjugation

Surface immobilization provides a useful platform for biosensing, drug screening, tissue engineering and other chemical and biological applications. However, some of the used reactions are inefficient and/or complicated, limiting their applications in immobilization. Herein, we use a spontaneous and catalyst-free amino-yne click bioconjugation to generate activated ethynyl group functionalized surfaces for fast immobilization of native proteins and cells. Biomolecules, such as bovine serum albumin (BSA), human IgG and a peptide of C(RGDfK), could be covalently immobilized on the surfaces in as short as 30 min. Notably, the bioactivity of the anchored biomolecules remains intact, which is verified by efficiently capturing target antibodies and cells from the bulk solutions. This strategy represents an alternative for highly efficient surface biofunctionalization.

Fast surface immobilization of native bioconjugates through a spontaneous amino-yne click reaction is realized.     

Structural variation in organically templated uranium sulfate fluorides

The ability of templated uranium sulfate fluorides to adopt diverse inorganic architectures is demonstrated in six novel materials. The inorganic structures present in [N2C6H16][UO2F2(SO4)](USFO-2), [N2C6H16][UO2F(SO4)]2(USFO-3), [N2C3H12][UO2F(SO4)]2.H2O (USFO-4), [N2C5H14][UO2F(H2O)(SO4]2(USFO-5), [N2C6H18]2[UO2F(SO4)]4.H2O (USFO-6) and [N2C3H12][UO2F(SO4)]2.H2O (USFO-7) range from infinite chains to five different layer topologies. The chain, and two of the five layers, have unprecedented structure types. These compounds illustrate the structural diversity within this new family of materials, arising from the varied coordination of the U6+ centres. Each material was synthesised under hydrothermal conditions, through reaction of uranyl acetate, sulfuric acid, HF(aq), water, and the respective organic template.     

In search of covalently bound tetra- and penta-oxygen species: a photoelectron spectroscopic and Ab initio investigation of MO4- and MO5- (M = Li,Na, K,Cs)

Although neutral and ionic O4(0/-/+) species have been observed experimentally and considered for energetic materials, O4(2-) and O5(2-) dianions have not yet been explored. O4(2-) is valent isoelectronic to the well-known ClO3- and SO3(2-) anions, and O5(2-) is valent isoelectronic to ClO4- and SO4(2-). All are stable, common anions in solutions and inorganic salts. In this article, we explore the possibility of making covalently bound O4(2-) and O5(2-) species stabilized in the forms of M+O4(2-) and M+O5(2-) (M = Li, Na, K, Cs) in the gas phase. Laser vaporization experiments using M-containing targets and an O2-seeded carrier gas yielded very intense mass peaks corresponding to MO4- and MO5-. To elucidate the structure and bonding of the newly observed MO4- and MO5- species, we measured their photoelectron spectra and then compared them with ab initio calculations and the spectra of ClO3-, Na+SO3(2-), ClO4-, and Na+SO4(2-). Careful analyses of the experimental and ab initio results showed, however, that the observed species are of the forms, O2-M+O2- and O2-M+O3-. The more interesting M+O4(2-) and M+O5(2-) species were found to be higher-energy isomers, but they are true minima on the potential energy surfaces, which suggests that it might be possible to synthesize bulk materials containing covalently bound tetra- and pentatomic oxygen building blocks.     

A chiroptical molecular switch with perfect stereocontrol

A modified version of the first generation unidirectional molecular motor showed >99% stereoselectivity in photo-induced isomerizations in both directions, thus functioning as a perfect chiroptical molecular switch.     

Fourier transform ion cyclotron resonance mass spectrometry using atmospheric pressure photoionization for high-resolution analyses of corticosteroids

Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS) was coupled with atmospheric pressure photoionization (APPI) for the first time and used for the analysis of several corticosteroids.1 The analytes showed excellent response using APPI when compared with both electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI). APPI has the advantage of requiring less heat for desolvation, resulting in less thermal degradation of the analytes and higher signal-to-noise than APCI. In terms of ultimate sensitivity, APPI is more efficient than either ESI or APCI for the analysis of corticosteroids. With some compounds, the high-resolution capability of FTICRMS was necessary to obtain an accurate mass due to contributions of the M(+.) (13)C isotope in the [M+H](+) ion peak.     

Flow injection-mini-column technique with ICP-AES detection for the isolation and preconcentration of the fast reactive aluminium fraction in waters

A flow injection mini-column system based on short reaction times with 8-hydroxyquinoline (oxine) with ICP-AES detection is described for the isolation and preconcentration of the “fast reactive” or “toxic” aluminium fraction in water samples. Using a 3 s reaction time with oxine (5 × 10^–4 mol/l) at pH 5.0, the “fast reactive” aluminium fraction is shown not to include the non-toxic AlF²⁺ species at low F^–: Al³⁺ molar ratios (0.3 : 1). The complexed aluminium is isolated in a stable and recoverable form on mini-columns of Amberlite XAD-2 (0.3 cm × 5.0 cm, resin particle size range 0.08 mm–0.16 mm)). The retained aluminium is recovered by “back-flushing” the analytical column with 1 mol/l HCl for final element specific detection by ICP-AES. Detection limits (after preconcentration) of 2 μg/l, a linear range of 0–500 μg/l, and possible preconcentration factors of up to 18 times are demonstrated with the present system. Implications for the possible solution of sample stability problems encountered with labile aluminium species analysis and the development of a “field sampling” technique are discussed, where the desired Al fraction is quantitatively retained in a stable form on mini-columns.     

Experimental Determination of the Isotherm at 15°C of the System Mg2+/Cl?, SO42–H2O

 The diagram of the ternary system Mg²⁺/Cl⁻, SO₄ ²⁻–H₂O was established at 15°C by means of analytical and conductimetric measurements. Three compounds were found in this diagram, which are MgSO₄·6H₂O, MgSO₄·7H₂O, and MgCl₂·6H₂O. The solubility field of MgSO₄·7H₂O is important whereas those of MgSO₄·6H₂O and MgCl₂·6H₂O are small. The compositions (mass-%) of the two invariant points determined by the two methods are: MgSO₄:MgCl₂=2.73:33.80 and MgSO₄: MgCl₂=3.38:28.91. Both the measured and the calculated isotherm at 15°C have been used for modelling of the diagram Mg²⁺/Cl⁻, SO₄ ²⁻–H₂O between 0 and 35°C. The polythermal invariant point was approximately located between 15 and 10°C.     

Structural and process controls of AIEgens for NIR-II theranostics

Aggregation-induced emission (AIE) is a cutting-edge fluorescence technology, giving highly-efficient solid-state photoluminescence. Particularly, AIE luminogens (AIEgens) with emission in the range of second near-infrared window (NIR-II, 1000–1700 nm) have displayed salient advantages for biomedical imaging and therapy. However, the molecular design strategy and underlying mechanism for regulating the balance between fluorescence (radiative pathway) and photothermal effect (non-radiative pathway) in these narrow bandgap materials remain obscure. In this review, we outline the latest achievements in the molecular guidelines and photophysical process control for developing highly efficient NIR-II emitters or photothermal agents with aggregation-induced emission (AIE) attributes. We provide insights to optimize fluorescence efficiency by regulating multi-hierarchical structures from single molecules (flexibilization) to molecular aggregates (rigidification). We also discuss the crucial role of intramolecular motions in molecular aggregates for balancing the functions of fluorescence imaging and photothermal therapy. The superiority of the NIR-II region is demonstrated by fluorescence/photoacoustic imaging of blood vessels and the brain as well as photothermal ablation of the tumor. Finally, a summary of the challenges and perspectives of NIR-II AIEgens for in vivo theranostics is given.

Structural and process controls of NIR-II AIEgens realize manipulating of radiative (R) and nonradiative (NR) decay for precise theranostics.     

Limitations and perspectives in the determination of carbofuran with various liquid chromatography-mass spectrometry interfacing systems

Column liquid chromatography with mass spectrometric detection (LC-MS) has been widely accepted as the preferred technique for the identification and quantification of polar and thermally labile compounds at trace levels. Over the last decade many different types of LC-MS interfacing techniques have been used for the determination of carbamate pesticides and especially for the N-methylcarbamate carbofuran. This article addresses the difficulties encountered with the various types of LC-MS interface and discusses recent alternatives for the determination of carbofuran. With thermospray and particle beam interfaces the quantification of carbofuran is affected by both the ion source pressure and temperature, whereas quantification using the recently developed atmospheric pressure ionization interfaces, atmospheric pressure chemical ionization, electrospray, and ionspray, is less dependent on these parameters.     

草酰胺桥联大环二羰四胺铜(Ⅱ)-钴(Ⅱ)异双核配合物的合成、结构、表征和电化学性质

合成了一种具有草酰胺桥联大环二羰四胺结构的 Cu( ) -Co( )异双核配合物 ,用红外光谱、电子光谱、摩尔电导、热重分析、室温磁矩、循环伏安等对其进行了表征 .初步推定 Cu( ) -Co( )异双核配合物具有草酰胺桥联大环二羰四胺结构 .室温磁矩测定表明 ,通过草酰胺桥联配体金属离子间有一定的反铁磁性自旋偶合作用 .循环伏安法测定了配合物的半波电位 ,实验表明 ,此类配合物能够稳定高价态 Cu( ) ,外延桥基配位对大环内腔 Cu( )离子的氧化还原过程无影响 .单核配合物 X射线晶体衍射研究表明 ,其为单斜晶系 ,空间群 P2 1 /c,a=0 .73 861 (1 5 ) nm,b=2 .1 2 1 1 (4 ) nm,c=0 .95 2 5 0 (1 9) nm,β=94.70 (3 )°,R1 =0 .0 5 1 3 ,w R2 =0 .1 1 77,Z=4.Cu( )处于大环四胺平面正方中心上方 0 .0 3 nm,并具有外延草酰胺桥