OICC Press International Journal of Biophotonics and Biomedical Engineering (IJBBE) 2980-9037 5 1 2025 09 06 Optical biosensor for detection of hemoglobin using ternary photonic crystals 10.71498/ijbbe.2025.1193386 EN Minoo Aghamohammadian Department of Biomedical Engineering, Tabriz Branch , Islamic Azad University , Tabriz , Iran Ali Vahedi Department of physics, Tabriz Branch,Islamic Azad University, Tabriz, Iran Siyamak Haghipour Department of Biomedical Engineering, Tabriz Branch , Islamic Azad University , Tabriz , Iran Journal Article 2025 09 06 Optical biosensors have attracted the attention of researchers because they have a unique ability to control the dispersal of photons and detect the natural shape of biomolecules. The main component of blood is hemoglobin, whose main function is to transport oxygen to body tissues and remove carbon dioxide from them. This article aims to simulate biosensors that can detect hemoglobin concentration using photonic crystals. For this purpose, we have used two structures with TiN/m/Ti  and AlXGa1-XN structural dielectrics, which have different refractive indices and can control light transmittance. Photonic crystals have a region called the photonic band gap (PBG), in which waves cannot propagate in the structure. layers inside the photonic crystal structure controlled and adjusted the defect modes and PBG properties. To find the best result, parameters such as the layer thickness, the light incident angle and the refractive index have been optimally selected. After examining the proposed structures, it was determined that both of structures are more optimal in wide defect layer. The results show that the TiN/m/AlXGa1-XN structure has narrow, maximum intensity detection modes and a broader bandgap at the selected wavelength range compared to the other structure.