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Design and Optimization of SiON Ring Resonator-Based Biosensors for Aflatoxin M1 Detection.

Guider R, Gandolfi D, Chalyan T, Pasquardini L, Samusenko A, Pucker G, Pederzolli C, Pavesi L - Sensors (Basel) (2015)

Bottom Line: Sensitivities and limit of detection (LOD) were also measured using glucose-water solutions and compared with expected results from simulations.We were able to detect the binding of aflatoxin for concentrations as low as 12.5 nm.The results open up the path for designing cost-effective biosensors for a fast and reliable sensitive analysis of AFM1 in milk.

View Article: PubMed Central - PubMed

Affiliation: Nanoscience Laboratory, Department of Physics, University of Trento, Via Sommarive 14, Povo (TN) 38123, Italy. romain.guider@unitn.it.

ABSTRACT
In this article, we designed and studied silicon oxynitride (SiON) microring-based photonic structures for biosensing applications. We designed waveguides, directional couplers, and racetrack resonators in order to measure refractive index changes smaller than 10-6 refractive index units (RIU). We tested various samples with different SiON refractive indexes as well as the waveguide dimensions for selecting the sensor with the best performance. Propagation losses and bending losses have been measured on test structures, along with a complete characterization of the resonator's performances. Sensitivities and limit of detection (LOD) were also measured using glucose-water solutions and compared with expected results from simulations. Finally, we functionalized the resonator and performed sensing experiments with Aflatoxin M1 (AFM1). We were able to detect the binding of aflatoxin for concentrations as low as 12.5 nm. The results open up the path for designing cost-effective biosensors for a fast and reliable sensitive analysis of AFM1 in milk.

No MeSH data available.


(Left) Bending losses of sample L2; (Right) Bending losses of sample L5.
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sensors-15-17300-f003: (Left) Bending losses of sample L2; (Right) Bending losses of sample L5.

Mentions: The results of the bending losses for L2 and L5 samples are presented in Figure 3. Concerning the L2 wafer (nSiON = 1.66), fairly high losses were found for waveguides of 1000 nm width and a bending radius of 100 µm (0.17 dB/90° bend), but the fact that lower losses were found for 900 nm width (0.1 dB/90° bend) leads us to think that this could be due to a problem in the coupling to the facet of the waveguide. For shorter radii, the losses increase exponentially. In the case of the L5 wafer (nSiON = 1.8), bending losses below 0.2 dB/90° bend were found for radii spanning from 100 µm to 50 µm for waveguides of 1000 nm width. Concerning the 900 nm width waveguide, losses are in the range of 0.2 dB/90° bend, while they increase drastically for shorter radii. Such measurements confirm the low losses for 100 µm radius structures, and thus the possibility of high performances sensors based on ring resonators.


Design and Optimization of SiON Ring Resonator-Based Biosensors for Aflatoxin M1 Detection.

Guider R, Gandolfi D, Chalyan T, Pasquardini L, Samusenko A, Pucker G, Pederzolli C, Pavesi L - Sensors (Basel) (2015)

(Left) Bending losses of sample L2; (Right) Bending losses of sample L5.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4541935&req=5

sensors-15-17300-f003: (Left) Bending losses of sample L2; (Right) Bending losses of sample L5.
Mentions: The results of the bending losses for L2 and L5 samples are presented in Figure 3. Concerning the L2 wafer (nSiON = 1.66), fairly high losses were found for waveguides of 1000 nm width and a bending radius of 100 µm (0.17 dB/90° bend), but the fact that lower losses were found for 900 nm width (0.1 dB/90° bend) leads us to think that this could be due to a problem in the coupling to the facet of the waveguide. For shorter radii, the losses increase exponentially. In the case of the L5 wafer (nSiON = 1.8), bending losses below 0.2 dB/90° bend were found for radii spanning from 100 µm to 50 µm for waveguides of 1000 nm width. Concerning the 900 nm width waveguide, losses are in the range of 0.2 dB/90° bend, while they increase drastically for shorter radii. Such measurements confirm the low losses for 100 µm radius structures, and thus the possibility of high performances sensors based on ring resonators.

Bottom Line: Sensitivities and limit of detection (LOD) were also measured using glucose-water solutions and compared with expected results from simulations.We were able to detect the binding of aflatoxin for concentrations as low as 12.5 nm.The results open up the path for designing cost-effective biosensors for a fast and reliable sensitive analysis of AFM1 in milk.

View Article: PubMed Central - PubMed

Affiliation: Nanoscience Laboratory, Department of Physics, University of Trento, Via Sommarive 14, Povo (TN) 38123, Italy. romain.guider@unitn.it.

ABSTRACT
In this article, we designed and studied silicon oxynitride (SiON) microring-based photonic structures for biosensing applications. We designed waveguides, directional couplers, and racetrack resonators in order to measure refractive index changes smaller than 10-6 refractive index units (RIU). We tested various samples with different SiON refractive indexes as well as the waveguide dimensions for selecting the sensor with the best performance. Propagation losses and bending losses have been measured on test structures, along with a complete characterization of the resonator's performances. Sensitivities and limit of detection (LOD) were also measured using glucose-water solutions and compared with expected results from simulations. Finally, we functionalized the resonator and performed sensing experiments with Aflatoxin M1 (AFM1). We were able to detect the binding of aflatoxin for concentrations as low as 12.5 nm. The results open up the path for designing cost-effective biosensors for a fast and reliable sensitive analysis of AFM1 in milk.

No MeSH data available.