Photonic crystal based sensor for detection of high glucose concentration in urine

In optical biosensors bio-molecules are unlabeled or unmodified and are detected in their natural forms. Photonic crystal based biosensors measure change in the refractive index induced by molecular interactions, which are related to the sample concentration instead of total sample mass. In this paper we have demonstrated a 2-dimensional photonic crystal based optical sensor with line defect which can detect different concentrations of glucose in urine from 0-15 mg/dL to 10 gm/dL in the wavelength range of 1530-1565 nm and it is indicator of presence of high glucose level in blood which is responsible for causing Diabetes Mellitus. MEEP (MIT Electromagnetic Equation Propagation) and MPB (MIT Photonic Bands) simulation tools have been used for modeling and designing of photonic crystal. It has been observed from the band structure that for minute variations (0.001) in refractive index of urine which occurs due to change in the concentration of glucose present in it, there will be a moderate shift in the transmitted output power and resonance frequency in the range of 0.293716 - 0.294065 (in Meep units) and hence it acts as a sensor. This indicates that it is highly sensitive for the change in refractive index.