Abstract: This invention describes a photonic sensing method and device based on the periodic dielectric structures of photonic forbidden band, in which the sensing process is carried out through the measurement of variation in signal amplitude as it exits the device. The variation in amplitude is due to a variation in the refraction index of the structure, as a consequence of the presence of the substances that are the object of the sensing. Among the advantages provided by the invention, it is worth mentioning its simplicity in the sensing process; its high level of integration, allowing for a design of reduced proportions; and its adaptability to dielectric structures of one, two or three dimensions.