Titanium dioxide waveguide

Performance andLong-Term Stability of the Adsorbed PLL(375)-g[5.6]-PEG(5) Layer. Once established on the surfece, the adsorbed layer of PLL(375)-g[5.6]-PEG(5) was found to be stable (that is, <5% loss in mass of the adsorbed layer after 1 week) and resistant to protein adsorption over 24 h at 37 °C under a flowing HEPES Zl solution, as shown in Figure 8. This experiment involved the in situ deposition, within the first hour, of a PLL(375)-g[5.6]-PEG(5) layer on the surface of a silicon/ titanium dioxide waveguide. Two subsequent eiqtosures to serum produced less than 20 ng/cm of surface-adsorbed protein. Eighteen hours later, two additional serum exposures similarly produced less than 20 ng/cm. Similar performance was observed i hen PBS was used as the buffer instead of HEPES ZL... 

Effect of Precontamination on PLL(375)-g[5.6]-PEG-(5) Adsorption. Metal oxide surfaces that exhibited large amounts of hydrocarbon surface contamination nevertheless adsorbed a layer of PLL(375)-g[5.6]-PEG(5) that suppressed subsequent serum adsorption. Titanium dioxide waveguides that were not cleaned according to the procedure described in section 1.4.1 exhibited substantial hydrocarbon surface contamination (see Tables 2 and 3 and Figure 2). However, these XPS data also indicate that an additional layer of PLL(375)-g[5.6]-PEG-(5) does, indeed, adsorb onto this contaminated surface. Furthermore, OWLS experiments showed that the typical adsorbed areal density of 120 ng/cm forms on contaminated titanium dioxide waveguides and that this adsorbed layer of polymer suppresses subsequent serum protein adsorption by about 95%. That is, the adsorption and performance characteristics of PLL(375)-g[5.6]-PEG(5) are identical in the case of both contaminated and cleaned titanium dioxide surfaces. 

The other platform is dielectrics, for example, silicon dioxide, silicon nitride, silicon oxynitride, tantalum pentoxide, and titanium dioxide. They can be deposited by various methods, such as plasma-enhanced chemical vapor deposition, thermal evaporation, electron-beam evaporation, and sputtering. There are a number of dielectrics with refractive indices ranging from 1.45 to 2.4, facilitating diverse waveguide designs to satisfy different specification. Dielectrics have two other... 

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