Disclosed herein is a luminescent photonic structure (10). The luminescent photonic structure (10) comprises a luminescent material (14) that when excited by an excitation light (11) having a wavelength within an excitation wavelength spectrum of the luminescent material (14) emits luminescent light having a luminescence wavelength spectrum. The luminescent photonic structure (10) comprises a photonic crystal (14) disposed between two other photonic crystals (12,16). The photonic crystal (14) has a photonic lattice period within one of the luminescence wavelength spectrum and the excitation wavelength spectrum. The two other photonic crystals (12,16) each have a photonic lattice period within the other of the luminescence wavelength spectrum and the excitation wavelength spectrum for reflecting one of excitation light and luminescent light propagating within the photonic crystal (12). Also disclosed herein is a method for fabricating a luminescent photonic structure, and a method for sensing a chemical substance.