The applications of covalent organic framework materials as fluorescence probes

As a new type of porous materials, covalent organic frameworks (COFs) have potential application prospects in the detection of pollutants with high selectivity and sensitivity. In this paper, the methods used to synthesize COFs were described including solvothermal synthesis, microwave synthesis, ionothermal synthesis and room temperature synthesis. And their advantages and disadvantages were analyzed. The applications of COFs as fluorescence probes to detect ions, small molecules, biomedicines and pH were given. The detection mechanisms were briefly summarized as fluorescence resonance energy transfer (FRET), energy competitive absorption (ECA), photo induced electron transfer (PET), intramolecular charge transfer (ICT), excited -state intramolecular proton transfer (ESIPT), aggregation -induced emission (AIE), coordination interaction and others.