Sensitivity Features of Double-Resonance Plasmonic Sensor

Abstract

The paper presents the results of a model investigation about the temporal dynamics of changes in the resonance excitation conditions of surface plasmon-polariton waves in a double-resonance plasmonic sensor at different thicknesses of the sensitive ligand layer. It was shown that the maximum sensor reaction rate to the emergence of analyte is observed at a ligand layer with 40–50 nm thickness. When the ligand layer thickness is less than 40 nm, the sensitivity of the sensor decreases sharply, and when the ligand thickness is increase over 60 nm, a delay in the sensor reaction is observed which due to the limited diffusion rate of the analyte into the ligand. The most effective mode of a plasmon sensor operation is the mode in which the angle of the exciting beam incidence is somewhat different from the resonance angle at condition when the analyte is absent.