We introduce structures of sensors based on defective one-dimensional quinary photonic crystals. The unit cell of the structure is composed of five layers of N-BAF10  /  KNbO₃  /  TiO₂  /  KNbO₃  /  N-BAF10, whereas blood cells under investigation are supposed to construct a defective layer in the middle of the structure. The basic principle of detection of the proposed sensor is based on the existence of the resonant mode, within the photonic bandgap of the transmittance spectrum, due to the presence of blood cells in the defect layer. We found that the characteristics of the resonant mode are dependent on the type of blood cells used, thickness of the defect layer, and the angle of incidence of radiation. The average values of sensitivity, quality factor, and figure of merit for all types of cancerous blood cells are found to be about 623  nm  /  RIU, 129,560, and 73,950, respectively, at normal incidence. These values increased to 717  nm  /  RIU, 426,000, and 318,600, respectively, as the angle of incident increased from 0 deg to 45 deg with a low limit of detection of 1.998  ×  10^−  7 at 45 deg. Our results indicate that the proposed structures are very efficient in sensing and identifying the type of cancerous blood cells.