Limits...
Optical Gratings Coated with Thin Si3N4 Layer for Efficient Immunosensing by Optical Waveguide Lightmode Spectroscopy.

Diéguez L, Caballero D, Calderer J, Moreno M, Martínez E, Samitier J - Biosensors (Basel) (2012)

Bottom Line: A thin layer of 10 nm of transparent silicon nitride was deposited on commercial optical gratings by means of sputtering.The quality of the layer was tested by x-ray photoelectron spectroscopy and atomic force microscopy.The potential of the Si3N4 as functional layer in a real-time biosensor opens new ways for the integration of optical waveguides with microelectronics.

View Article: PubMed Central - PubMed

Affiliation: Department of Electronics, University of Barcelona, C/Martí i Franquès 1, Barcelona, ES 08028, Spain. lorena.dieguez@unisa.edu.au.

ABSTRACT
New silicon nitride coated optical gratings were tested by means of Optical Waveguide Lightmode Spectroscopy (OWLS). A thin layer of 10 nm of transparent silicon nitride was deposited on commercial optical gratings by means of sputtering. The quality of the layer was tested by x-ray photoelectron spectroscopy and atomic force microscopy. As a proof of concept, the sensors were successfully tested with OWLS by monitoring the concentration dependence on the detection of an antibody-protein pair. The potential of the Si3N4 as functional layer in a real-time biosensor opens new ways for the integration of optical waveguides with microelectronics.

No MeSH data available.


Related in: MedlinePlus

XPS spectra of the activated silicon nitride coated Optical Waveguide Lightmode Spectroscopy (OWLS) chip (a) full energy range spectrum and (b) high resolution spectrum of the Si 2p peak, showing its deconvolution into three contributions. After the chemical activation procedure with NaOH solution, a high content of O can be observed, which is in accordance with the presence of SiO2.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4263575&req=5

biosensors-02-00114-f003: XPS spectra of the activated silicon nitride coated Optical Waveguide Lightmode Spectroscopy (OWLS) chip (a) full energy range spectrum and (b) high resolution spectrum of the Si 2p peak, showing its deconvolution into three contributions. After the chemical activation procedure with NaOH solution, a high content of O can be observed, which is in accordance with the presence of SiO2.

Mentions: The effects in the chemical composition of the outmost part of the silicon nitride layer produced by the chemical activation process with the NaOH were investigated by means of XPS. Figure 3(a) plots the surface full XPS spectrum of the activated layer, where it can be observed that there is a huge content of oxygen (up to 34% in atomic content). These results agree with the literature, where Si3N4 surfaces have been oxidized following the same procedure [30]. Moreover, it can be also observed that the ratio Si:N does greatly exceed the stoichiometric ratio of the silicon nitride, being in this case Si6.8N4. In order to investigate this in more detail, a high-resolution spectrum of the 2p Si peak was performed and analyzed. The peak could be deconvoluted into three contributions (Figure 3(b)), coming from three different oxidation states corresponding to silicon nitride, silicon oxide and silicon [30,31]. These results prove the presence of an oxygen-rich surface that will be then further functionalized by the TEA reagent.


Optical Gratings Coated with Thin Si3N4 Layer for Efficient Immunosensing by Optical Waveguide Lightmode Spectroscopy.

Diéguez L, Caballero D, Calderer J, Moreno M, Martínez E, Samitier J - Biosensors (Basel) (2012)

XPS spectra of the activated silicon nitride coated Optical Waveguide Lightmode Spectroscopy (OWLS) chip (a) full energy range spectrum and (b) high resolution spectrum of the Si 2p peak, showing its deconvolution into three contributions. After the chemical activation procedure with NaOH solution, a high content of O can be observed, which is in accordance with the presence of SiO2.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4263575&req=5

biosensors-02-00114-f003: XPS spectra of the activated silicon nitride coated Optical Waveguide Lightmode Spectroscopy (OWLS) chip (a) full energy range spectrum and (b) high resolution spectrum of the Si 2p peak, showing its deconvolution into three contributions. After the chemical activation procedure with NaOH solution, a high content of O can be observed, which is in accordance with the presence of SiO2.
Mentions: The effects in the chemical composition of the outmost part of the silicon nitride layer produced by the chemical activation process with the NaOH were investigated by means of XPS. Figure 3(a) plots the surface full XPS spectrum of the activated layer, where it can be observed that there is a huge content of oxygen (up to 34% in atomic content). These results agree with the literature, where Si3N4 surfaces have been oxidized following the same procedure [30]. Moreover, it can be also observed that the ratio Si:N does greatly exceed the stoichiometric ratio of the silicon nitride, being in this case Si6.8N4. In order to investigate this in more detail, a high-resolution spectrum of the 2p Si peak was performed and analyzed. The peak could be deconvoluted into three contributions (Figure 3(b)), coming from three different oxidation states corresponding to silicon nitride, silicon oxide and silicon [30,31]. These results prove the presence of an oxygen-rich surface that will be then further functionalized by the TEA reagent.

Bottom Line: A thin layer of 10 nm of transparent silicon nitride was deposited on commercial optical gratings by means of sputtering.The quality of the layer was tested by x-ray photoelectron spectroscopy and atomic force microscopy.The potential of the Si3N4 as functional layer in a real-time biosensor opens new ways for the integration of optical waveguides with microelectronics.

View Article: PubMed Central - PubMed

Affiliation: Department of Electronics, University of Barcelona, C/Martí i Franquès 1, Barcelona, ES 08028, Spain. lorena.dieguez@unisa.edu.au.

ABSTRACT
New silicon nitride coated optical gratings were tested by means of Optical Waveguide Lightmode Spectroscopy (OWLS). A thin layer of 10 nm of transparent silicon nitride was deposited on commercial optical gratings by means of sputtering. The quality of the layer was tested by x-ray photoelectron spectroscopy and atomic force microscopy. As a proof of concept, the sensors were successfully tested with OWLS by monitoring the concentration dependence on the detection of an antibody-protein pair. The potential of the Si3N4 as functional layer in a real-time biosensor opens new ways for the integration of optical waveguides with microelectronics.

No MeSH data available.


Related in: MedlinePlus