Recent advances in photonic crystal-based sensors

Photonic crystal (PC) is an emerging optical microstructure material with adjustable dielectric constant, which can vary with its space periodically. It has exhibited excellent application prospects for the detection of heat, force, magnetism, chemical substances, and biomolecules due to its unique photonic band-gap and tailorable optical performances. Herein, we present the progress of the properties, construction methods, and functional regulation of PC materials, as well as their applications in physical, chemical, and biological sensors. In terms of material properties, the periodic structures, optical properties, electromagnetic properties, and biological properties of PC-based materials are introduced. For the construction of PC materials, one-dimensional, two-dimensional, three-dimensional, and hybrid PCs are demonstrated and discussed. In addition, we discuss functional regulation of PCs and analyze the research status of PCs such as the molecular imprinting, metal–organic frameworks, fluorescence enhancement, and bio-enhancement from the perspective of the interactions between PCs and other functional substances. Then, the applications of PC-based stimuli-responsive materials in physical sensing (temperature, humidity, stress, etc.), chemical sensing (organic solvents and their vapors, pH, heavy metal ions, etc.), and biosensing (enzymes, nucleic acids, antibodies, biomacromolecules, etc.) are introduced and discussed in detail. Finally, the future development of PC-based sensors is prospected.