Application of an OLED integrated with BEF and giant birefringent optical (GBO) film in a SPR biosensor

This study aims to improve the signal sensitivity of a portable surface plasmon resonance (SPR) sensor system. An organic light emitting diode (OLED) was integrated with a brightness enhancement film (BEF) and a giant birefringent optical (GBO) film as a light source to construct the SPR based on an OLED–BEF–GBO film. A method for calculating the SPR signal by summing the differences in optical intensity at two different wavelengths was used to minimize the effect of the noise error that particularly occurs in a portable SPR device. The experimental results indicated that the limit of detection (LOD) of the SPR using an Au sensing layer has an effective refractive index change of 7.8 × 10−6 RIU. Furthermore, for the SPR using Au/Ag sensing metal layers, an LOD of 3.2 × 10−6 RIU was achieved due to the improved sensitivity and resolution value compared with the use of an Au sensing layer. The use of the SPR device in a bio-affinity assay to test the interaction between goat anti-mouse immunoglobulin G (IgG) and mouse IgG protein achieved a LOD of approximately 40.6 pg/mL.