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.

Sensitivity optimization in whispering gallery mode optical cylindrical biosensors

“…In this work, we propose the use of cylindrical micro-resonators with optimized structural parameters for optical biosensing. This kind of optical biosensor detects changes in the surrounding refractive index through the electromagnetic (EM) field evanescent depth of WGMs, travelling outside the cylindrical resonator boundary, providing label-free sensing ability [8,9,10]. WGM resonances in these structures can have two degrees or orders of freedom i and l or ν, where i is radial order and l or ν is the angular order of a WGM.…”

High-Q and temperature stable photonic biosensor based on grating waveguides

“…Based on these factors, a number of researchers have investigated the capability of the photonic sensors. The most frequently reported work has been concentrated on surface plasmons resonance (Chiu et al 2005;Ni et al 2015;Azzam et al 2016;Mohanty et al 2015), disk resonators (Boud et al 2001;Guider et al 2015), photonic crystal based devices (Dutta and Pal 2013;Derbali et al 2011), and interferometers (Liu et al 2013;Sahu et al 2016). Further, the response of a Surface Plasmon resonance (SPR) sensor device is strongly dependent on the quality of the deposited material, especially the thickness and roughness of the coating.…”

Electrochemical Biosensors for the Determination of Toxic Substances Related to Food Safety Developed in South America: Mycotoxins and Herbicides

“…It is not a coincidence that precisely aflatoxins are the only ones that have been proven to be carcinogenic to humans [25]. For this reason, the enormous number of articles that have been published related to the development of analytical methods for the determination of AFB [26][27][28][29][30][31][32][33] and AFM1 [34][35][36][37] at trace levels is understandable. However, another important set of mycotoxins may be mentioned, regardless if their carcinogenic effect has not been categorically established for humans at present, such as ochratoxin, citrinin, sterigmatocystin and Fusarium mycotoxins [3].…”

“…However, another important set of mycotoxins may be mentioned, regardless if their carcinogenic effect has not been categorically established for humans at present, such as ochratoxin, citrinin, sterigmatocystin and Fusarium mycotoxins [3]. Some recent reports related to the use of biosensors for the determination of mycotoxins that deserve sustained attention can be cited, such as those for aflatoxins [26][27][28][29][30][31][32][33][34][35][36][37], citrinin [38,39], sterigmatocystin [40][41][42], Fusarium mycotoxins [43] and ochratoxin A [44][45][46][47][48]. Undoubtedly, specialized agencies in developed countries have been at the forefront of these challenges.…”