Design of magnetic photonic crystal microdroplet for sensitive detection of cationic organic pollutants by the coupled resonance effect.

Photonic crystals (PCs), periodically arranged nanoparticles, have emerged with extraordinary optical properties for light manipulation owing to their photonic band gaps (PBGs). Here, a novel strategy and method was developed for efficient enrichment and sensitive detection of cationic organic pollutants in water. Size-controlled FeO@poly (4-styrenesulfonic acid-co-maleic acid) (FeO@PSSMA) was prepared, and high surface charge were formed with the coating of PSSMA layer on the surface of FeO, which could be used for adsorption and removal of cationic organic pollutants.