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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) Sensorgram recorded using a sample from the L2 wafer in TM polarization. The high step-like response is due to the refractive index mismatch produced by the small content of Dimethyl sulfoxide (DMSO) in the solution. This solvent is needed to dissolve the AFM1 in the buffer solution; (Right) Specific binding sensorgrams obtained from the curves in (Left) by subtracting the bulk shift induced by the DMSO content. The dashed curves are exponential fittings for the evaluation of the rate constants and of the initial slopes [4].
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sensors-15-17300-f009: (Left) Sensorgram recorded using a sample from the L2 wafer in TM polarization. The high step-like response is due to the refractive index mismatch produced by the small content of Dimethyl sulfoxide (DMSO) in the solution. This solvent is needed to dissolve the AFM1 in the buffer solution; (Right) Specific binding sensorgrams obtained from the curves in (Left) by subtracting the bulk shift induced by the DMSO content. The dashed curves are exponential fittings for the evaluation of the rate constants and of the initial slopes [4].

Mentions: To perform our sensing experiments, we flew several solutions containing different aflatoxin concentrations over the sensor devices. More details on the experimental process are available in [13]. Figure 9 represents the sensorgrams obtained for the L2 sample in TM polarization. Between each measurement, we performed an injection of glycine solution (100 mM glycine-HCl, pH 2) in order to regenerate the aptamers on the surface of the sensors.


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) Sensorgram recorded using a sample from the L2 wafer in TM polarization. The high step-like response is due to the refractive index mismatch produced by the small content of Dimethyl sulfoxide (DMSO) in the solution. This solvent is needed to dissolve the AFM1 in the buffer solution; (Right) Specific binding sensorgrams obtained from the curves in (Left) by subtracting the bulk shift induced by the DMSO content. The dashed curves are exponential fittings for the evaluation of the rate constants and of the initial slopes [4].
© Copyright Policy
Related In: Results  -  Collection

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

sensors-15-17300-f009: (Left) Sensorgram recorded using a sample from the L2 wafer in TM polarization. The high step-like response is due to the refractive index mismatch produced by the small content of Dimethyl sulfoxide (DMSO) in the solution. This solvent is needed to dissolve the AFM1 in the buffer solution; (Right) Specific binding sensorgrams obtained from the curves in (Left) by subtracting the bulk shift induced by the DMSO content. The dashed curves are exponential fittings for the evaluation of the rate constants and of the initial slopes [4].
Mentions: To perform our sensing experiments, we flew several solutions containing different aflatoxin concentrations over the sensor devices. More details on the experimental process are available in [13]. Figure 9 represents the sensorgrams obtained for the L2 sample in TM polarization. Between each measurement, we performed an injection of glycine solution (100 mM glycine-HCl, pH 2) in order to regenerate the aptamers on the surface of the sensors.

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.