Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) on cluster-assembled super-hydrophilic nanoporous titania films deposited on hydrophobic conductive-polymer substrates feature a unique combination of surface properties that significantly improve the possibilities of capturing and processing biological samples before and during the MALDI-MS analysis without changing the selected sample target (multi-dimensional MALDI-MS). In contrast to pure hydrophobic surfaces, such films promote a remarkable biologically active film porosity at the nanoscale due to the soft assembling of ultrafine atomic clusters. This unique combination of nanoscale porosity and super-hydrophilicity provides room for effective sample capturing, while the hydrophilic-hydrophobic discontinuity at the border of the dot-patterned film acts as a wettability-driven containment for sample/reagent droplets. In the present work, we evaluate the performance of such advanced surface engineered reactive containments for their benefit in protein sample processing and characterization. We shortly discuss the advantages resulting from the introduction of the described chips in the MALDI-MS workflow in the healthcare/clinical context and in MALDI-MS bioimaging (MALDI-MSI).

High-throughput flame spray pyrolysis affords a low-loading Pt catalyst supported on cerium oxide, which is an excellent material for selective C2H2 semihydrogenation at 180 °C, with near-complete conversion and high selectivity towards C2H4 (87.1%).

The semi-hydrogenation of acetylene (C2H2 + H-2 = C2H4, Delta H = -172 kJ mol(-1)) is a well-studied reaction that is important for purification of ethylene, C2H4, feed used in polyethylene production. Pd-based catalysts are most commonly used to remove acetylene from ethylene feed prior to Ziegler-Natta polymerization because acetylene is a poison for Ziegler-Natta catalysts. New applications of the analogous catalytic processes, with similar requirements for the conversion and selectivity, are considered for the storage of H-2 within the context of the H-2 economy. Here, a combination of experimental and theoretical studies was employed to explore the performance of synthesized Pd nanoparticles and the feasibility of using computational modelling for predicting their catalytic properties. Specifically, a model 5%Pd/Al2O3 nanocatalyst was successfully synthesized using high throughput flame spray pyrolysis (FSP) method. As a catalyst for acetylene semi-hydrogenation, the material shows high conversion of 97%, a modest selectivity of 62%, and a turnover frequency of ethylene formation of 5 s(-1). The experimental data were further supported by computational modelling of catalytic properties. Results of microkinetic simulations, based on parameters obtained from DFT calculations, over a Pd-30/Al2O3(100) model system were correlated with experiments. The insights from this direct comparison of theory and experiments provide indications for future improvements of the theoretical predictions and for novel types of materials with improved catalytic properties. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Ultrafine cobalt and ruthenium clusters are deposited on carbon paper substrates by cluster beam deposition using a matrix assembly cluster source and a pulsed microplasma cluster source, respectively. When used to catalyze the oxygen evolution reaction (OER), the cobalt and ruthenium clusters show electrocatalytic performance superior to the state-of-the-art Ru/C and RuO2 nanoparticle catalysts on both a mass and a specific-surface-area basis. Typically, the cobalt clusters can deliver 10 mA cm–2 at a low overpotential of 320 mV and show a small Tafel slope of 50 mV dec–1 and a mass-based turnover frequency of 0.01 s–1 at an overpotential of 300 mV, outperforming many cobalt-based OER catalysts.

This chapter contains sections titled: Introduction Experimental Coating Characterization Sensing and Biotech Results Conclusion Acknowledgements

The preparation of effective conventional antibody microarrays depends on the availability of high quality material and on the correct accessibility of the antibody active moieties following their immobilization on the support slide. We show that spotting bacteria that expose recombinant antibodies on their external surface directly on nanostructured-TiO2 or epoxy slides (purification-independent microarray – PIM) is a simple and reliable alternative for preparing sensitive and specific microarrays for antigen detection. Variable domains of single heavy-chain antibodies (VHHs) against fibroblast growth factor receptor 1 (FGFR1) were used to capture the antigen diluted in serum or BSA solution. The FGFR1 detection was performed by either direct antigen labeling or using a sandwich system in which FGFR1 was first bound to its antibody and successively identified using a labeled FGF. In both cases the signal distribution within each spot was uniform and spot morphology regular. The signal-to-noise ratio of the signal was extremely elevated and the specificity of the system was proved statistically. The LOD of the system for the antigen was calculated being 0.4ng/mL and the dynamic range between 0.4ng/mL and 10μg/mL. The microarrays prepared with bacteria exposing antibodies remain fully functional for at least 31days after spotting. We finally demonstrated that the method is suitable for other antigen–antibody pairs and expect that it could be easily adapted to further applications such as the display of scFv and IgG antibodies or the autoantibody detection using protein PIMs.

Spectroscopic ellipsometry (SE) has been used to investigate the adsorption of yeast cytochrome c (YCC) on gold films. YCC is a prototypical molecular system to evaluate the sensitivity and reliability of optical methods in probing conformational changes upon adsorption at surfaces. Measurements have been performed in situ in aqueous solutions at room temperature. We have applied to monolayer-thick YCC films the same scheme of analysis of SE spectra used in our recent works on thiolate self-assembled monolayers on gold, exploiting the so-called δΨ and δΔ difference spectra. A comparison between δΨ and δΔ spectra obtained from YCC adsorption on flat and cluster-assembled nanostructured gold films, obtained by supersonic cluster beam deposition is proposed. For both kinds of substrate δΨ and δΔ, difference spectra show well-defined features related to molecular optical absorptions typical of the so-called heme group, in particular the Soret band at about 410 nm. These features appear in the same position found for molecules in solution, suggesting that YCC native conformation is maintained upon adsorption also in the case of a substrate with typical roughness at the nanoscale.

Protein microarray technologies are rapidly expanding to fulfill current needs of proteome discovery for disease management. Nanostructured materials have been shown to present interesting features when used in biological settings: nanostructured titanium oxide film (ns-TiOx), synthesized by supersonic cluster beam deposition (SCBD), has recently emerged as a biocompatible substrate in different biological assays. The ns-TiOx surface is characterized by a morphology at the nanoscale that can be tuned to modulate specific biomolecule-material interactions. Here we present a systematic characterization of ns-TiOx coatings as protein binding surfaces, comparing their performances with those of most common commercial substrates in protein and antibody microarray assays. Through a robust statistical evaluation of repeatability in terms of coefficient of variation (CV) analysis, we demonstrate that ns-TiOx can be used as reliable substrate for biochips in analytical protein microarray application.