Research on Wavelength Modulated D-typeFiber Surface Plasmon Resonance Hemoglobin Concentration Sensor

To improve the sensitivity of human hemoglobin concentration detection, we propose a surface plasmon resonance D-type optical fiber hemoglobin concentration sensor decorated with a gold-graphene surface configuration. The optimal sensor configuration includes 70 nm thick gold film, 33-layer graphene film, and 12 mm long D-type sensing region. The proposed sensor is based on wavelength interrogation mode, with the light wavelength ranging from 350 nm to 1400 nm. We use two sensors, with graphene and without graphene, to detect the refractive index of hemoglobin samples, which vary from 1.3310 to 1.3611. Results show that the fitted refractive index sensitivity of the sensor decorated with gold and graphene reaches 4793.40 nm/RIU, 33.4% higher than that of the sensor decorated only with gold. The proposed sensor, coated with gold and graphene film, exhibits a concentration sensitivity of 1.21 nm/g/L and a resolution of 0.0826 g/L for hemoglobin concentration detection.