Modeling of glucose sensor based on Fano resonance excitation intitania nanotube photonic crystal-coated by titanium nitride as aplasmonic material

The brilliant optical properties of plasmonic metal nitrides improve many applications. Modeling of light-confining Fano resonance based on a titanium nitride (TiN)-coated titanium oxide one-dimensional photonic crystal is investigated as a glucose sensor. There is a cavity layer filled with a glucose solution between the TiN thin layer and photonic crystals. The reflection spectrum is calculated numerically by using Bruggeman's effective medium approximation and transfer matrix method. The effect of plasmonic layer thickness, cavity layer thickness, and the thicknesses of the titanium oxide nanotube layers are optimized to achieve a high performance sensor. The result shows that the Fano resonances shift to higher wavelengths with increasing glucose concentration. The best sensitivity of the optimized biosensor is about 3798.32 nm/RIU. Also, the sensor performance parameters such as the limit of detection, figure of merit, and quality factor are discussed. The proposed sensor can be of potential interest due to its easy fabrication and higher performance than many previous reported sensors in the sensing field.