Selective and sensitive morpholine-type rhodamine B-based colorimetric and fluorescent chemosensor for Fe(III) and Fe(II)

The development of chemosensor materials is crucial for the early detection of hazardous materials, such as heavy metal ions and infectious viruses. In this study, three rhodamine B (RhB) derivatives (referred to as Rh-OS, Rh-OO, and Rh-SO) bearing a morpholine-type 6-membered ring as colorimetric, fluorescent sensors were synthesized, and fluorescence responses to various metal ions (Fe3+, Ce2+,Pb2+, cr(6+), ce(2+),Mn2+, Cd2+,Hg2+,K+, Na+, Mg2+, Li+, Ca2+, As3+, Co2+, Ni2+, and Zn2+) were investigated. Rh -OS, Rh 00, and Rh-SO exhibited high sensitivity to Fe2+ and Fe3+, with the formation of a 1:1 (ligand: metal) complex, as evidenced by the UV-vis absorption and photoluminescence spectra. Luminescence turn on was explained by the transfer of resonance energy from the morpholine-type moiety to the RhB framework. In addition, the selectivity of Fe3+ and Fe2+ was evaluated by 2D and 3D photoluminescence imaging. (C) 2017 Elsevier B.V. All rights reserved.