title: Design and Optimization of SiON Ring Resonator-Based Biosensors for Aflatoxin M1 Detection.
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.
authors.affiliation: Nanoscience Laboratory, Department of Physics, University of Trento, Via Sommarive 14, Povo (TN) 38123, Italy. romain.guider@unitn.it.
authors.forename: Romain
authors.initials: R
authors.lastname: Guider
authors.affiliation: Nanoscience Laboratory, Department of Physics, University of Trento, Via Sommarive 14, Povo (TN) 38123, Italy. davide.gandolfi@unitn.it.
authors.forename: Davide
authors.initials: D
authors.lastname: Gandolfi
authors.affiliation: Nanoscience Laboratory, Department of Physics, University of Trento, Via Sommarive 14, Povo (TN) 38123, Italy. Tatevik.Chalyan@unitn.it.
authors.forename: Tatevik
authors.initials: T
authors.lastname: Chalyan
authors.affiliation: LaBSSAH, Fondazione Bruno Kessler, Via Sommarive 18, Povo (TN) 38123, Italy. pasqua@fbk.eu.
authors.forename: Laura
authors.initials: L
authors.lastname: Pasquardini
authors.affiliation: Nanoscience Laboratory, Department of Physics, University of Trento, Via Sommarive 14, Povo (TN) 38123, Italy. pucker@fbk.eu.|Centre for Materials and Microsystems, Fondazione Bruno Kessler, Via Sommarive 18, Povo (TN) 38123, Italy. pucker@fbk.eu.
authors.forename: Alina
authors.initials: A
authors.lastname: Samusenko
authors.affiliation: Centre for Materials and Microsystems, Fondazione Bruno Kessler, Via Sommarive 18, Povo (TN) 38123, Italy. pucker@fbk.eu.
authors.forename: Georg
authors.initials: G
authors.lastname: Pucker
authors.affiliation: LaBSSAH, Fondazione Bruno Kessler, Via Sommarive 18, Povo (TN) 38123, Italy. pederzo@fbk.eu.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Pederzolli
authors.affiliation: Nanoscience Laboratory, Department of Physics, University of Trento, Via Sommarive 14, Povo (TN) 38123, Italy. lorenzo.pavesi@unitn.it.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Pavesi
mesh_terms: D016607:Aflatoxin M1 / Q000032:analysis*; D015374:Biosensing Techniques / Q000295:instrumentation*; D004867:Equipment Design; D057230:Limit of Detection; D060328:Magnetic Phenomena; D055620:Optical Phenomena; D017655:Silicon Compounds / Q000737:chemistry*
chemical_list: D017655:Silicon Compounds; D016607:Aflatoxin M1
keywords: Whispering Gallery Mode; aflatoxin; biosensor; label-free; limit of detection; ring resonator; sensitivity; waveguide