Due to the increase in blood diseases such as
diabetes, detecting the concentration of some biomolecules
relating to these diseases, such as glucose, is very important;
therefore, designing high quality, cheap, and easy-to-build
biosensors is one of the most important targets of researchers.
For this reason, a graphene-gold ellipse grating SPR biosensor
has been proposed based on FEM modeling. While analyzing the
extinction curve, an SPR mode was observed in the mid-infrared
region. The sensitivity and quality factor of this mode were
calculated with small changes in the sensing mediums' refractive
index. After studying the SPR mode, the geometry structure and
the properties of the incoming light beam were optimized, to
increase the sensitivity and quality factor of the sensor, and the
highest values of 1782 nm/RIU and 21214 were obtained,
respectively. The proposed biosensor was based on the surface
plasmons resonance and placed in the free label category also can
measure with a high sensitivity and excellent performance many
biomolecules and biological cells such as blood, glucose, water
and MDCK by detecting the refractive their index variation.
Furthermore, materials with a refractive index in the range of
1.100 to 2.100, up to a precision of 0.00005, are also detectable