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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

The laser beam is coupled inside the waveguide at different incoupling angles (depending on the covering layer). The spectrum is followed by the photodiodes placed at each end of the waveguide. The dash line shows the incoupling spectra of the bare chip covered with silicon nitride, and the continuous line after antibody functionalization.
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biosensors-02-00114-f005: The laser beam is coupled inside the waveguide at different incoupling angles (depending on the covering layer). The spectrum is followed by the photodiodes placed at each end of the waveguide. The dash line shows the incoupling spectra of the bare chip covered with silicon nitride, and the continuous line after antibody functionalization.

Mentions: Once fabricated, the functionalized silicon nitride chip performance in the OWLS instrument was checked. Figure 5 shows the plot of OWLS incoupling angle spectra after the silicon nitride layer deposition. It can be seen that both TE and TM peaks are perfectly visible after the silicon nitride deposition and the signal to noise ratio increases from 41 to 56 in the OWLS spectra when the chip is functionalized with antibodies with respect to the bare Si3N4 coated chip. This is related to the decrease in the roughness as a flatter surface avoids scattering during the incoupling of the laser. The same figure shows the OWLS incoupling angle peaks after the chip functionalization with the anti-HSA antibody layer. Worth noticing, the functionalization of the chip did not affect the chip structure neither covered the whole chip surface, allowing the coupling of the laser. The chips may be used a minimum of three times, maintaining their properties before the nitride layer gets damaged.


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)

The laser beam is coupled inside the waveguide at different incoupling angles (depending on the covering layer). The spectrum is followed by the photodiodes placed at each end of the waveguide. The dash line shows the incoupling spectra of the bare chip covered with silicon nitride, and the continuous line after antibody functionalization.
© Copyright Policy
Related In: Results  -  Collection

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

biosensors-02-00114-f005: The laser beam is coupled inside the waveguide at different incoupling angles (depending on the covering layer). The spectrum is followed by the photodiodes placed at each end of the waveguide. The dash line shows the incoupling spectra of the bare chip covered with silicon nitride, and the continuous line after antibody functionalization.
Mentions: Once fabricated, the functionalized silicon nitride chip performance in the OWLS instrument was checked. Figure 5 shows the plot of OWLS incoupling angle spectra after the silicon nitride layer deposition. It can be seen that both TE and TM peaks are perfectly visible after the silicon nitride deposition and the signal to noise ratio increases from 41 to 56 in the OWLS spectra when the chip is functionalized with antibodies with respect to the bare Si3N4 coated chip. This is related to the decrease in the roughness as a flatter surface avoids scattering during the incoupling of the laser. The same figure shows the OWLS incoupling angle peaks after the chip functionalization with the anti-HSA antibody layer. Worth noticing, the functionalization of the chip did not affect the chip structure neither covered the whole chip surface, allowing the coupling of the laser. The chips may be used a minimum of three times, maintaining their properties before the nitride layer gets damaged.

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