Improving surface plasmon resonance imaging of DNA by creating new gold and silver based surface nanostructures

The use of nanoparticles (NPs) can substantially improve the analytical performance of surface plasmon resonance imaging (SPRi) in general, and in DNA sensing in particular. In this work, we report on the modification of the gold surface of commercial biochips with gold nanospheres, silica-coated gold nanoshells, and silver nanoprisms, respectively. The NPs were tethered onto the surface of the chip and functionalized with a DNA probe. The effects of tethering conditions and varying nanostructures on the SPRi signals were evaluated via hybridization assays. The results showed that coupling between planar surface plasmons and electric fields, generated by localized surface plasmons of the NPs, is mandatory for signal enhancement. Silver nanoprisms gave the best results in improving the signal change at a target DNA concentration of <50 nM by +50 % (compared to a conventional SPRi chip). The limit of detection for the target DNA was 0.5 nM which is 5 times less than in conventional SPRi.

Thermodynamics of Proton Association of Polyacrylates and Polymethacrylates in NaCl(aq)

Enthalpies of protonation of polyacrylates and polymethacrylates with different molecular weights in aqueous NaCl solutions, 0 I 2 mol-L^–1 were determined by titration calorimetry at 25°C. H values are dependent on both the neutralization degree, , and the molecular weight of polyacids. T S of protonation was obtained using pK values already reported and the present H results. Empirical equations for the dependence on I, , and molecular weight are reported for both H and T S.     

Identification and quantification of different species in animal fibres by LC/ESI‐MS analysis of keratin‐derived proteolytic peptides

In the present paper, a proteomic method for species determination in fibres has been developed. Keratin was extracted from yak, wool and cashmere fibres and digested by trypsin, providing peptide mixtures that were analyzed by liquid chromatography coupled with electrospray mass spectrometry (LC/ESI‐MS) in order to identify peptidic species‐specific markers able to differentiate the fibres. Several suitable peptide markers were identified and validated in different fibres of different origin and having undergone different technological treatments, showing 100% specificity and 100% selectivity. Most of the peptide markers were also identified by means of high‐resolution mass spectrometry, confirming the origin from species‐specific keratin sequences. Some peptides were also used for the quantification of the different species in mixed fibres by LC/ESI‐MS. Validation experiments and blind tests confirmed their ability to act as very specific quantitative and qualitative markers. The method here developed is a valid complement to the standard benchmark methods for fibre identification and quantification and will be very useful for assessing the authenticity of textile products. Copyright © 2013 John Wiley & Sons, Ltd.     

Complexes of helium with neutral molecules: Progress toward a quantitative scale of bonding character

The complexes of helium with nearly 30 neutral molecules (M) were investigated by various techniques of bonding analysis and symmetry-adapted perturbation theory (SAPT). The main investigated function was the local electron energy density H( r ), analyzed, in particular, so to estimate the degree of polarization (DoP) of He in the various He(M). As we showed recently (Borocci et al., J. Comput. Chem., 2019, 40, 2318–2328), the DoP is a quantitative index that is generally informative about the role of polarization (induction plus charge transfer [CT]) and dispersion in noncovalent noble gas complexes. As further evidence in this regard, we presently ascertained quantitative correlations between the DoP(He) of the He(M) and indices based on the electron density ρ( r ), including the molecular electrostatic potential at the He M bond critical point, as well as the percentage contributions of induction and dispersion to the SAPT binding energies. Based also on the explicit evaluation of the CT, accomplished through the study of the charge-displacement function, we derived a quantitative scale that ranks the He(M) according to their dispersive, inductive, and CT bonding character. Our taken approach could be conceivably extended to other types of noncovalent complexes.     

Molecular routes for spin cluster qubits

We report on real molecular complexes and propose strategies that explore the possibility of implementation of specific quantum computation architectures with molecular spin systems. We focus on Cr3+ carboxylate derivatives and use the Loss-DiVincenzo scheme as reference.     

From Solid-Solution Electrodes and the Rocking-Chair Concept to Today's Batteries

Lithium-ion batteries (LIBs) have become ubiquitous power sources for small electronic devices, electric vehicles, and stationary energy storage systems. Despite the success of LIBs which is acknowledged by their increasing commodity market, the historical evolution of the chemistry behind the LIB technologies is laden with obstacles and yet to be unambiguously documented. This Viewpoint outlines chronologically the most essential findings related to today's LIBs, including commercial electrode and electrolyte materials, but furthermore also depicts how the today popular and widely emerging solid-state batteries were instrumental at very early stages in the development of LIBs.     

Protein Interactions with Polymer Coatings and Biomaterials

Protein adsorption is considered to be the most important factor of the interaction between polymeric biomaterials and body fluids or tissues. Water‐mediated hydrophobic and hydration forces as well as electrostatic interactions are believed to be the major factors of protein adsorption. A systematic analysis of various monolayer systems has resulted in general guidelines, the so‐called “Whitesides rules”. These concepts have been successfully applied for designing various protein‐resistant surfaces and are being studied to expand the understanding of protein–material interactions beyond existing limitations. Theories on the mechanisms of protein adsorption are constantly being improved due to the fast‐developing analytical technologies. This Review is aimed at improving these empirical guidelines with regard to present theoretical and analytical advances. Current analytical methods to test mechanistic hypotheses and theories of protein–surface interactions will be discussed. Special focus will be given to state‐of‐the‐art bioinert and biospecific coatings and their applications in biomedicine.     

Tin-mediated synthesis of lyso-phospholipids

1-O-Acyl-sn-glycero-3-phosphocholine and 1-O-acyl-sn-glycero-3-phosphoric acid have been prepared selectively and with high yields from the corresponding diols, glycerophosphoryl choline and glycerol-3-phosphate. Starting from the diols, the activated tin ketals were prepared in 2-propanol by reaction with dialkyltin oxide. The intermediates were acylated in the same solvent with long-chain fatty acid chlorides, giving the corresponding 1-acyl-lyso-phospholipids in high yield and with complete regioselectivity. The catalytic nature of the tin-mediated acylation and the relevance of the solvent are discussed.