Terahertz photonic crystal fiber for sensing the creatinine level in the blood

In this work, THz photonic crystal fiber (PCF) is used to detect the creatinine level in the blood with high sensitivity. The sensing technique depends on increasing the light interaction with the analyte infiltrated into the air holes in the fiber core region. In this regard, most of the light power should be confined through the analyte region. This will increase the relative sensitivity coefficient that is proportional to the analyte power fraction. The operation of the suggested sensor is based on studying the light–analyte interaction at different creatinine concentrations by detecting the change of the analyte power fraction against the change of the creatinine level in the blood at the THz range 0.5–1.5 THz. The effective mode index (n eff ), effective material loss (EML), effective modal area (A eff ), and relative sensor sensitivity are calculated using the full vectorial finite element method. Additionally, the different geometrical parameters are studied to maximize the sensor’s sensitivity. The proposed THz-PCF has a 93% and 95% relative sensitivity for x - and y -polarized modes, respectively. Therefore, the suggested THz-PCF biosensor gives a promising usage in measuring the creatinine level in the blood.