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Ispra, Italy

Ceccone G.,EC JRC IHCP | Leung B.O.,McMaster University | Perez-Roldan M.J.,EC JRC IHCP | Valsesia A.,EC JRC IHCP | And 4 more authors.
Surface and Interface Analysis | Year: 2010

Synchrotron-based X-ray photoemission electron microscopy (X-PEEM), atomic force microscopy (AFM), time of flight secondary ion mass spectrometry (ToF-SIMS) and X-ray photoelectron spectroscopy (XPS) have been used to visualize and characterize plasma polymerized acrylic acid (ppAA) and poly ethylene oxide (PEO)-like microstructures. Micropatterned microstructures have been fabricated with electron-beam lithography to obtain contrasted ppAA/PEO-like structures. A surface area of 500 μm × 500 μm was patterned with arrays of 5 μm diameter circles and 500 μm × 5 μm lines. Samples have been analyzed before and after immersion of ubiquitin protein solutions. AFM and X-PEEM results indicated that the protein adsorbed preferentially on the ppAA regions for both circular and line patterns. For both circular and line patterns, the protein preferentially adsorbed to the ppAA regions. Copyright © 2010 John Wiley & Sons, Ltd.

Perez-Roldan M.,EC JRC IHCP | Colpo P.,EC JRC IHCP | Gilliland D.,EC JRC IHCP | Ceccone G.,EC JRC IHCP | Rossi F.,EC JRC IHCP
Surface and Interface Analysis | Year: 2013

In this work, we present a method to produce micro and nanostructured surfaces containing bioadhesive features embedded in an antifouling matrix. These surfaces are fabricated by combining plasma polymerization and electron beam lithography. This combination allows the fabrication of structured surfaces in just two steps and without the use of solvents. ToF-SIMS analysis demonstrates that the e-beam treatment induces a chemical change at the surface depending upon the radiation dose employed. In particular, a decrease of peaks characteristic of the PEO-like fragments (e.g. CH3O+, C3H7O+, C3H5O 2 +) and a correspondent increase of hydrocarbon moieties such as C2H3 + and C3H 3 + is observed in the irradiated zones. These results are supported by XPS analysis that indicate a slight reduction of the intensity of the C-O component in the C1s core level spectrum after irradiation similar to that observed in UV-treated PEO-like films. Experiments with proteins show a preferential adhesion of the biomolecules to the irradiated zone indicating the good potential of this technique for the development of nanostructured biosensing platforms. Copyright © 2012 John Wiley & Sons, Ltd. Copyright © 2012 John Wiley & Sons, Ltd.

Strola S.,EC JRC IHCP | Ceccone G.,EC JRC IHCP | Gilliand D.,EC JRC IHCP | Valsesia A.,EC JRC IHCP | And 2 more authors.
Surface and Interface Analysis | Year: 2010

In this work, quartz crystal microbalance (QCM) crystal surfaces were analyzed in order to study the behavior of protein attachment on fouling substrates. In this context, covalent and noncovalent immobilization of different proteins [bovine serum albumin (BSA), collagen] has been investigated. For the noncovalent immobilization, silicon dioxide-coated QCM crystals were used, while the covalent immobilization was obtained via plasma-polymerized acrylic acid film (ppAA) deposited onto the QCM substrates. Two different activation processes, namely, reaction with trifluoroacetic anhydride (TFAA) and 1 -ethyl-3, 3-dimethyl carbodiimide (EDC) and W-hydroxysuccinimide (NHS), were studied. After the QCM experiments, all samples were analyzed with X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry to gain information on the surface chemistry and composition. The results indicate that the protein adsorption process depends on protein concentration, whereas the complement activation effectiveness depends on protein type. In particular, for BSA, XPS and QCM data show a greater immobilization in the case of EDC/NHS activation compared to the TFAA, whereas in the case of collagen, only the EDC/NHS activation was able to yield covalent coupling. Copyright © 2010 John Wiley & Sons, Ltd.

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