Synthesis and characterization of a sensitive and selective Fe3+ fluorescent sensor based on novel sulfonated calix[4]arene-based host-guest complex

A novel fluorescent sensor was prepared from sulfonated calix[4]arene (SC4A) by the host-guest complexation method using the fluorescent dye rhodamine B (RB) as a structure-directing agent. The crystal structure of the host-guest complex (RB@(SC4A)(3)) was confirmed by X-ray diffraction studies while its performance and sensing mechanism for metal ion pollutants were characterized using fluorescence and nuclear magnetic resonance spectroscopies. The results showed that RB@(SC4A)(3) had a triangular branch structure resulting from host-guest mediation of the interactions between the three SC4A host molecules and the three terminal groups of the guest molecule RB. The host-guest complex exhibited sensitive and selective sensing towards Fe3+ ions via a fluorescence quenching mechanism. The results indicated that RB@(SC4A)(3) could be a promising sensitive and selective fluorescent sensor for metal ion pollutants monitoring. It also provided new insights into the synthesis of calixarene-based host-guest complex. (C) 2021 Published byElsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.