Photonic crystal(PC)is composed of two and more mediums with periodic nanostructure.The unique optical property and characteristic nanostructure of the PC provide effective means for biological and chemical analyses.In our group,we developed a series of analytical methods by using self-assembled PC.1)Label-free detection of biomolecule.By utilizing the volume and refractive index change of biomolecules in PC,we realized label-free detection and visual detection of biomolecules.2)Analysis of gas.Mesoporous PC with high specific surface area was developed.By using this kind of material,we realized the analysis of gas molecules with PC.3)Multiplex detection.One of the key techniques of multiple biological analysis is to identify different biological events simultaneously.Biomolecule encoding is the core technique for the multiplex detection.By taking advantage of the spectrum-encoding ability of the PC,we fabricated the encoding carriers for biomolecules with low fluorescence background and high-stability.4)PC paper-based chips.We realized the separation of biomolecules by taking advantage of the periodic nanostructure of PC.Meanwhile,the fluorescent signal for detection was enhanced due to the stop-band of the PC.5)Organ chip analysis.We fabricated 3D cell scaffolds on microfluidic chips to simulate the in vivo environment for cell growth.On-line analysis was also realized with the PC microcarriers.