Orthogonal Chemical Functionalization of Au/SiO/TiW Patterned Substrates.

Macropatterned and micropatterned gold/silicon dioxide/titanium tungsten (Au/SiO/TiW) substrates were orthogonally functionalized: three different molecules (monovalent silane, thiol, and phosphonic acid) were used to specifically form organolayers on Au, SiO, or TiW areas of patterned substrates. The orthogonality of the functionalization (i.e.

Oxidized Titanium Tungsten Surface Functionalization by Silane-, Phosphonic Acid-, or Ortho-dihydroxyaryl-Based Organolayers.

Titanium tungsten (TiW) films (200 nm thick) were cleaned by oxygen plasma, and the resulting oxidized surfaces were functionalized by 3-aminopropylphosphonic acid (APPA), 3-ethoxydimethylsilylpropylamine (APDMES), or dopamine (DA) to form three different organolayers. The three resulting organolayers were characterized by X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry, and Fourier transform infrared spectroscopy analyses. The stability of each organolayer was investigated.

Orthogonal chemical functionalization of patterned Au/TiW substrate for selective immobilization of nanoparticles.

The evolution of nanobiosensors stresses the need for multi-material nanopatterned surfaces to enhance sensing performances. Titanium tungsten (TiW) has been mastered and routinely implemented in nanoelectronic devices, in a reproducible way and at industrial production scales. Such a material may be envisioned for use in (bio)chemical nanoelectronic sensors, but the surface functionalization of such material has yet to be studied.

Novel Concept of Gas Sensitivity Characterization of Materials Suited for Implementation in FET-Based Gas Sensors.

We propose a novel technique to investigate the gas sensitivity of materials for implementation in field-effect transistor-based gas sensors. Our technique is based on the measurement of the surface charge induced by gas species adsorption, using an electrometer. Platinum sensitivity to hydrogen diluted in synthetic air has been evaluated with the proposed charge measurement technique in the operation temperature range from 80 to 190 °C at constant H concentration of 4 % and for different concentrations ranging from 0.

pH driven addressing of silicon nanowires onto Si3N4/SiO2 micro-patterned surfaces.

pH was used as the main driving parameter for specifically immobilizing silicon nanowires onto Si3N4 microsquares at the surface of a SiO2 substrate. Different pH values of the coating aqueous solution enabled to experimentally distribute nanowires between silicon nitride and silicon dioxide: at pH 3 nanowires were mainly anchored on Si3N4; they were evenly distributed between SiO2 and Si3N4 at pH 2.8; and they were mainly anchored on SiO2 at pH 2.