Design of GO-Ag-functionalized FeO@CS composite for magnetic adsorption of rhodamine B.

In this study, a novel magnetic composite (FeO@CS/GO/Ag) modified with chitosan (CS), graphene oxide (GO) and Ag nanoparticles (Ag NPs) was successfully prepared as an efficient adsorbent for detection of rhodamine B (RB) combined with a fluorescence technique. The properties of the magnetic composite were confirmed by field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and vibrating sample magnetometry. The components of FeO@CS/GO/Ag endowed it with excellent extraction performance and convenient operation. The main parameters affecting extraction and desorption efficiency were all investigated systematically. Under the optimized experimental conditions, the proposed method showed linear ranges (0.2-6.0 μg L) with = 0.9992. The limits of detection (LODs) and quantification (LOQs) were 0.05 and 0.2 μg L ( = 3), respectively. FeO@CS/GO/Ag exhibited outstanding extraction efficiency for RB, compared with CS-coated FeO nanoparticles (FeO@CS) and GO-modified FeO@CS (FeO@CS/GO). The applicability of the proposed method was investigated by analyzing four real samples (waste water, soft drink, shampoo, and red pencil) and the spiked recoveries ranged between 94% and 97% with RSD ranging from 3% to 6%, which showed that the proposed method had satisfactory practicability and operability.