Previous theoretical works suggested that superhydrophobicity could be enhanced through partial inhibition of the quantum vacuum modes at the surface of a broadband-absorber metamaterial which acts in the extreme ultraviolet frequency domain. This effect would then compete with the classical Cassie-Baxter interpretation of superhydrophobicity. In this article, we first theoretically establish the expected phenomenological features related to such a kind of "quantum" superhydrophobicity. Then, relying on this theoretical framework, we experimentally study patterned silicon surfaces on which organosilane molecules were grafted, all the coated surfaces having similar characteristic pattern sizes but different profiles. Some of these surfaces can indeed freeze quantum photon modes while others cannot. While the latter ones allow hydrophobicity, only the former ones allow for superhydrophobicity. We believe these results lay the groundwork for further complete assessment of superhydrophobicity induced by quantum fluctuations freezing.

Biosensors are composite devices suitable for the investigation of receptor-ligand interactions. In this paper we present the specific application to a membrane embedded protein of a new sensor device, so-called BIA-ATR, based on Atten- uated Total Reflection-Fourier Transform Infrared (ATR-FTIR) spectroscopy. It consists in a functionalised ATR germanium crystal whose surface has been covalently modified to adsorb a biomembrane. Detection of the ligand-receptor interaction is achieved using FTIR spectroscopy. We report the specific detection of the phosphorylation/dephosphorylation of the H + /K + gastric ATPase. The H + ,K + -ATPase is a particularly large protein entity. This glycosylated protein contains more than 1300 residues and is embedded in a lipid membrane. Yet we demonstrate that the BIA-ATR sensor is capable of monitoring the binding of a single phosphate on such a large protein entity. Furthermore, we also demonstrate the potential of the approach to monitor the kinetics of binding and dissociation of the ligand.

A two-step wet chemistry protocol has been developed for the surface derivatization of poly(ethylene terephthalate) (PET) track-etched membrane used as cell culturing support, that is, (a) activation by trifluorotriazine (1 M in acetonitrile (ACN), 30 degrees C, 3 h); (b) coupling to amine-terminated molecules, namely 3,5-bis(trifluoromethyl)benzylamine ((F)Tag), (L)-4,5-[H-3]-lysine, and Gly-Arg-Gly-Asp-Ser (GRGDS) pentapeptide (10(-3) M in PB-ACN, 1:1 (v/v), 20 degrees C, 17 h). The grafting rates determined by X-ray photoelectron spectroscopy, from the F/C and N/C atomic ratios, are in the range of 100-140 pmol/cm(2) (apparent surface), whereas the liquid scintillation counting assays give higher values (180-d230 pmol/cm(2)) corresponding to the open surface reactivity. PET-g-(F)Tag is reasonably stable under two usual sterilization conditions of biomaterials, that is, steam heating at 121 degrees C and gamma-irradiation at 25 kGy. On the other hand, PET-g-GRGDS is found to be stable only under ionization radiation (84% of remaining peptide molecules), but damaged in a large extent by the autoclave treatment (23% of remaining peptide molecules). The surfaces of the sterilized PET and PET-g-GRGDS samples have been characterized by water contact angle measurement and by atomic force microscopy analysis in air and under water. Comparatively to the corresponding nonsterilized surfaces, gamma-irradiated surfaces are slightly more hydrophilic and also slightly more rough and jagged. (C) 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 195-208, 2010

Biosensors based on intrinsic detection methods have attracted growing interest. The use of Fourier transform infra-red (FTIR) spectroscopy with the attenuated internal total reflection (ATR) mode, in the biodetection context, requires appropriate surface functionalization of the ATR optical element. Here, we report the direct grafting of a thin organic layer (about 20 Å depth) on the surface of a germanium crystal. This covering, constructed with novel amphiphilic molecules 2b (namely, 2,5,8,11,14,17,20-heptaoxadocosan-22-yl-3-(triethoxysilyl) propylcarbamate), is stable for several hours under phosphate buffered saline (PBS) flux and features protein-repulsive properties. Photografting of molecule 5 (namely, O-succinimidyl 4-(p-azidophenyl)butanoate) affords the activated ATR element, ready for the covalent fixation of receptors, penicillin recognizing proteins BlaR-CTD for instance. The different steps of the previous construction have been monitored by water contact angle (θw) measurements, spectroscopic ellipsometry (covering depth), X-ray photoelectron spectroscopy (XPS) by using a fluorinated tag for the control of surface reactivity, and FTIR-ATR spectroscopy for the structural analysis of grafted molecules. Indeed, contrarily to silicon device, germanium device offers a broad spectral window (1000–4000 cm−1) and thus amide I and II absorption bands can be recorded. This work lays the foundations for the construction of novel FTIR biosensors.

ADVERTISEMENT RETURN TO ISSUEPREVNoteNEXTPCL−PEG-Based Nanoparticles Grafted with GRGDS Peptide: Preparation and Surface Analysis by XPSVincent Pourcelle†, Sabrina Devouge†, Marie Garinot‡, Véronique Préat‡, and Jacqueline Marchand-Brynaert*†View Author Information Université Catholique de Louvain, Unité de Chimie Organique et Médicinale, Bâtiment Lavoisier, place Louis Pasteur 1, B-1348 Louvain-la-Neuve, Belgium and Université Catholique de Louvain, Unité de Pharmacie Galénique, Avenue E. Mounier 73-20, 1200 Brussels, Belgium* Corresponding author. E-mail: email:[email protected]. Telephone: +32-10-472740 . Fax:+32-10-474168.†Unité de Chimie Organique et Médicinale.‡Unité de Pharmacie Galénique.Cite this: Biomacromolecules 2007, 8, 12, 3977–3983Publication Date (Web):November 27, 2007Publication History Received31 July 2007Revised19 September 2007Published online27 November 2007Published inissue 1 December 2007https://pubs.acs.org/doi/10.1021/bm700841yhttps://doi.org/10.1021/bm700841ybrief-reportACS PublicationsCopyright © 2007 American Chemical SocietyRequest reuse permissionsArticle Views1335Altmetric-Citations44LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Copolymers,Ligands,Nanoparticles,Nitrogen,X-ray photoelectron spectroscopy Get e-Alerts