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--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. The FeO@PSSMA after adsorbing cationic organic pollutant were assembled to magnetic photonic crystal microdroplet (MPCM) structure in an external magnetic field, which was used as surface-enhanced Raman scattering (SERS) substrate. By coupling the magnetically tuned PBGs with Raman laser wavelength, the light utilization efficiency can be improved and the coupled resonance effect was greatly enhanced. The enhancement factor (EF) of MB was more than 800 attributing to the dual function of enrichment and coupled resonance effect of MPCM. The developed analytical strategy is the first time to use MPCM as a SERS substrate to realize the sensitive detection of 10 nmol L MB in real water, which greatly improves the application of MPCM in the field of contaminant analysis and detection in water.

中文翻译：

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耦合共振效应灵敏检测阳离子有机污染物的磁性光子晶体微滴设计


光子晶体（PC）是一种周期性排列的纳米粒子，由于其光子带隙（PBG）而具有非凡的光学特性，可用于光操纵。这里，开发了一种新的策略和方法，用于水中阳离子有机污染物的高效富集和灵敏检测。制备了尺寸可控的FeO@聚(4-苯乙烯磺酸--马来酸)(FeO@PSSMA)，FeO表面包覆PSSMA层形成高表面电荷，可用于吸附和去除阳离子有机污染物。 Fe3O@PSSMA吸附阳离子有机污染物后，在外磁场中组装成磁性光子晶体微滴（MPCM）结构，作为表面增强拉曼散射（SERS）基底。通过磁调谐PBG与拉曼激光波长的耦合，可以提高光利用效率，并大大增强耦合谐振效果。由于MPC的富集和耦合共振效应的双重作用，MB的增强因子（EF）超过800。所开发的分析策略首次使用MPCM作为SERS底物实现了真实水中10 nmol·L MB的灵敏检测，极大提高了MPCM在水中污染物分析检测领域的应用。