Incorporation of Rhodamine into a Host Polymer via In-Situ Generated Isocyanato Group and Application for the Detection of Cu²⁺ Ion

A rhodamine-based fluorescent polymer P(MMA-co-RB) has been synthesized via an intermediate NCO-containing polymer generated by the Lossen rearrangement reaction. The fluorescent property of P(MMA-co-RB) with regard to metal ions, such as Cu2+, Fe3+, Cr3+, Al3+, Zn2+, Co2+, Sn2+ and Ag+, was studied by fluorescence emission spectroscopy. The results demonstrate that the fluorescence intensity of P(MMA-co-RB) decreased gradually with an increase of the concentration of Cu2+ ion. Furthermore, a test strip made of P(MMA-co-RB) can be used for fast and quantitative determination of Cu2+ ion. In the presence of Cu2+ ion, the sensory tester undergoes distinct changes in fluorescence intensity and visible color