Theoretical investigation of Vernier effect based sensors with hybrid porous silicon-polymer optical waveguides

Abstract

International audienceA new combination of porous silicon and polymer optical waveguides is investigated for two different designs of Vernier effect based sensors for the surface detection of Bovine Serum Albumin molecules (BSA). The hybrid structures studied consist of two cascaded micro-resonators for one and a micro-resonator cascaded with a Mach-Zehnder for the other. Because of its high specific surface and bio-compatibility, we use porous silicon to implement the waveguides in the sensing part of the sensor into which BSA molecules are grafted. Polymer waveguides are then used for the reference part of the sensor because of their low optical losses. We consider the opto-geometric parameters of both waveguides for single mode propagation. Finally, optimized designs, taking into account standard experimental wavelength shift measurement limitation are presented for both structures. We demonstrate a theoretical Limit Of Detection (LOD) of 0.019 pg.mm-2 and a sensitivity of 12.5 nm/(pg.mm-2) with these hybrid sensors. To our knowledge, these values are lower by a factor of 8 for the LOD and higher, by a factor of 200 for the sensitivity, as compared to state of the art Vernier effect biosensors

Optical conductivity-based ultrasensitive mid-infrared biosensing on a hybrid metasurface

“…To compare with typical surface plasmon resonance biosensors, we also estimated the detection limit in weight per unit area (pg/mm 2 ), which is an important figure of merit for surface-based sensors. In the specific case of glucose sensing, the detection limit was approximately 1.3 pg/mm 2 when the gap was 30 nm, and further lowered to 0.043 pg/mm 2 when the gap was 10 nm, which was three times better than that for the state-of-the-art Vernier effect plasmonic resonance biosensors (see Supplementary Information section 5.3 for details on the calculation of the detection limit) 50 . However, these values should not represent the theoretical limit of our method, considering that the optical conductivity change is mainly dependent on the number of charges transferred to graphene rather than the molecular weights of the adsorbed molecules.…”

Porous Silicon-Based Photonic Biosensors: Current Status and Emerging Applications

“…Improvement in sensitivity by substituting the simple PSi Fabry–Pérot interferometer with sophisticated multilayered-optical structures has already been vastly established, and research work in recent years has focused on optimization of these complex structures for improving their sensitivity. ,− Such structures include Bragg mirrors, , rugate filters, ,,− microcavities, ,,,,,− Thue–Morse structures, waveguides, , Vernier effect-based structures, Bloch surface wave structures, ring resonators, , and diffraction gratings . Weiss and co-workers extensively studied biosensors based on DNA-PNA hybridization with different PSi-based optical structures.…”

Nanosilicon-Based Composites for (Bio)sensing Applications: Current Status, Advantages, and Perspectives

“…Thual et al proposed a theoretical model of hybrid Psi–polymer optical waveguides for BSA detection [119]. Due to the PSi high specific surface and biocompatibility, it was used as the sensing part of the sensor.…”