Surface plasmon resonance sensor apparatus having multiple dielectric layers

Abstract

A surface plasmon resonance (SPR) spectrometer sensor apparatus for measuring a property of an analyte substance that can be adsorbed on a surface by directing a beam of incident radiation on the apparatus at an incident angle relative thereto, receiving a beam of reflected radiation off the apparatus, and measuring dips in reflected radiation as a function of incident angle or wavelength, the dips being indicative of resonances in the apparatus. The SPR spectrometer comprises a conductive layer having a first side which receives incident radiation, and having a second side opposite to the first side; and a dielectric stack having first and second sides opposite to each other, the first side being in contact with the conductive layer, the second side for receiving an analyte sample to be disposed thereon. The dielectric stack includes a plurality of dielectric layers having respective thicknesses and indices of refraction, each successive one of the plurality of dielectric layers having an index of refraction which is alternatingly higher than, and lower than, the indices of refraction of adjacent ones of the plurality of dielectric layers. The plurality of dielectric layers including a first dielectric layer at the first side of the dielectric stack, and a last dielectric layer at the second side of the dielectric stack, the last dielectric layer having a boundary surface for contacting the received analyte sample, and having an index of refraction so as to achieve total internal reflection (TIR) at the boundary surface.