Performance of white organic light-emitting diode for portable optical biosensor

A white organic light-emitting diode (OLED) with enhanced sensitivity has been demonstrated as a novel light source in a portable surface plasmon resonance (SPR) optical biosensor. A disposable broad-spectral OLED was employed on the leg side of isosceles trapezoid prism for a fixed angle of incident light. Bimetallic Ag/Au composition layers were used as sensing layers and their structures evaluated such that the wavelength resonance occurred at the peak of the light spectrum. The SPR signal detection applied differential intensities at two reference wavelengths. We show that the integration of a white spectral OLED on an SPR sensor improved the sensor's sensitivity by ∼19.29% compared to an SPR sensor system using a green OLED for a bimetallic Ag/Au sensing layer. The limit of detection (LOD) of 2.4 × 10^-6 refractive index units (RIU) has been established in the range of refractive index samples (Δn) around 3.6 × 10^-3 RIU. This optical sensor demonstrated the capability of rapid, real-time monitoring operation. The activation of self-assembled monolayer (SAM), antibody immobilization, and biomolecular interaction detection of immunoglobulin G (IgG) protein are recorded successfully with a detection limit around 40.3 pg/mL.