Multi-channel SPR biosensor based on PCF for multi-analyte sensing applications

This paper presents a theoretical investigation of a novel holey fiber (Photonic Crystal Fiber (PCF)) multi-channel biosensor based on surface plasmon resonance (SPR). The large gold coated micro fluidic channels and elliptical air hole design of our proposed biosensor aided by a high refractive index over layer in two channels enables operation in two modes; multi analyte sensing and self-referencing mode. Loss spectra, dispersion and detection capability of our proposed biosensor for the two fundamental modes (HE x 11 and HE y 11 ) have been elucidated using a Finite Element Method (FEM) and Perfectly Matching Layers (PML)

Design of plasmonic-waveguiding structures for sensor applications

Surface plasmon resonance has become a widely accepted optical technique for studying biological and chemical interactions. Among others, detecting small changes in analyte concentration in complex solutions remains challenging, e.g., because of the need of distinguishing the interaction of interest from other effects. In our model study, the resolution ability of plasmonic sensing element was enhanced by two ways. Besides an implementation of metal-insulator-metal (MIM) plasmonic nanostructure, we suggest concatenation with waveguiding substructure to achieve mutual coupling of surface plasmon polariton (SPP) with an optical waveguiding mode. The dependence of coupling conditions on the multilayer parameters was analyzed to obtain optimal field intensity enhancement.Web of Science99art. no. 122

Fabrication of Polymer Based Optical Devices for Communication and Sensing

Polymer waveguides present a potentially low cost alternative to electronics in communication systems. Polymers offer relatively straightforward and economical fabrication when compared to conventional materials. In this study, a fabrication process for Bragg gratings in polymer waveguides was developed. Waveguides were designed using finite-element analysis, patterned via e-beam lithography, and a detailed fabrication method was developed. Surface-Plasmon Resonance (SPR) is a widely accepted method for biological and chemical sensing. Measurement of bulk refractive index changes and specific surface binding is a crucial part in any biosensing. Design and fabrication of a novel self-referencing SPR sensor is described and its functionality is tested

Advances in optoplasmonic sensors – combining optical nano/microcavities and photonic crystals with plasmonic nanostructures and nanoparticles

AbstractNanophotonic device building blocks, such as optical nano/microcavities and plasmonic nanostructures, lie at the forefront of sensing and spectrometry of trace biological and chemical substances. A new class of nanophotonic architecture has emerged by combining optically resonant dielectric nano/microcavities with plasmonically resonant metal nanostructures to enable detection at the nanoscale with extraordinary sensitivity. Initial demonstrations include single-molecule detection and even single-ion sensing. The coupled photonic-plasmonic resonator system promises a leap forward in the nanoscale analysis of physical, chemical, and biological entities. These optoplasmonic sensor structures could be the centrepiece of miniaturised analytical laboratories, on a chip, with detection capabilities that are beyond the current state of the art. In this paper, we review this burgeoning field of optoplasmonic biosensors. We first focus on the state of the art in nanoplasmonic sensor structures, high quality factor optical microcavities, and photonic crystals separately before proceeding to an outline of the most recent advances in hybrid sensor systems. We discuss the physics of this modality in brief and each of its underlying parts, then the prospects as well as challenges when integrating dielectric nano/microcavities with metal nanostructures. In Section 5, we hint to possible future applications of optoplasmonic sensing platforms which offer many degrees of freedom towards biomedical diagnostics at the level of single molecules

MULTI-MODE SELF-REFERENCING SURFACE PLASMON RESONANCE SENSORS

Surface-plasmon-resonance (SPR) sensors are widely used in biological, chemical, medical, and environmental sensing. This dissertation describes the design and development of dual-mode, self-referencing SPR sensors supporting two surface-plasmon modes (long- and short-range) which can differentiate surface binding interactions from bulk index changes at a single sensing location. Dual-mode SPR sensors have been optimized for surface limit of detection (LOD). In a wavelength interrogated optical setup, both surface plasmons are simultaneously excited at the same location and incident angle but at different wavelengths. To improve the sensor performance, a new approach to dual-mode SPR sensing is presented that offers improved differentiation between surface and bulk effects. By using an angular interrogation, both surface plasmons are simultaneously excited at the same location and wavelength but at different angles. Angular interrogation offers at least a factor of 3.6 improvement in surface and bulk cross-sensitivity compared to wavelength-interrogated dual-mode SPR sensors. Multi-mode SPR sensors supporting at least three surface-plasmon modes can differentiate a target surface effect from interfering surface effects and bulk index changes. This dissertation describes a tri-mode SPR sensor which supports three surface plasmon resonance modes at one single sensing position, where each mode is excited at a different wavelength. The tri-mode SPR sensor can successfully differentiate specific binding from the non-specific binding and bulk index changes

Estudio y diseño de dispositivos ópticos biosensores depositados con películas delgadas basados en detección de longitud de onda de resonancias

A lo largo de esta tesis se presenta el estudio y diseño de varias plataformas de guía-ondas ópticas, con el fin de ver su viabilidad a la hora de usarlas como biosensores sobre fibra óptica u otros sustratos fotónicos. En este trabajo se depositan estructuras ópticas como una fibra monomodo desnuda, un estrechamiento en fibra óptica o una fusión de fibras mono – multi – monomodo (SMS) con películas delgadas de materiales usando técnicas nanotecnológicas como el ensamblado capa a capa (LbL-assembly) o el sputtering. Además, se dedica un capítulo al estudio de microresonadores toroidales depositados por rotación (spin-coating). El objetivo es generar o mejorar las prestaciones en resolución y sensibilidad de los fenómenos resonantes que se pueden obtener en estas estructuras ópticas, para luego detectar reacciones biológicas que den lugar a un futuro diagnóstico precoz de enfermedades.Along this thesis, the study and design of several optical waveguide platforms is presented, in order to check their viability when used as biosensors based on either optical fiber or other photonic substrates. In this work, some fiber-optic-based structures such as cladding removed multimode structures, tapered single-mode fibers and single-mode – multimode – single-mode fibers are deposited with thin-films of materials, using nanotechnology-based methods such as layer-by-layer assembly (LbL-assembly) or sputtering. Moreover, a brief chapter is focused on the study of toroidal microring resonators deposited by spin-coating. The final objective is to generate or enhance the parameters of the resonant phenomena obtained in these structures, in terms of resolution and sensitivity. Then, a biological detection is addressed and characterized, to see if they are able to perform a future early diagnosis for illnesses.La realización de este trabajo ha sido posible gracias a las aportaciones económicas recibidas por parte de la Universidad Pública de Navarra (UPNA), así como del patrocinio de la UPNA y del Ministerio de Economía y Competitividad, a través de los proyectos CICYT fondos FEDER TEC2010-17805, TEC2013-43679-R e IPT-2011-1212-920000 (PMEL).Programa Oficial de Doctorado en Ingeniería y Arquitectura (RD 1393/2007)Ingeniaritzako eta Arkitekturako Doktoretza Programa Ofiziala (ED 1393/2007