Fabrication of fluorescent polymer latexes based on rhodamine B derivatives and their reusable films for Fe3+ detection

The stimulus-responsive P(MMA-co-BA-co-RhBUEA) latexes were prepared by miniemulsion polymerization of butyl acrylate (BA), methyl methacrylate (MMA), and a rhodamine-based probe RhBUEA. Their chemical composition and structures were characterized by FTIR and UV–Vis spectral analysis. Meanwhile, the effects of AIBN, SDS, and RhBUEA content on the miniemulsion polymerization and the morphology of latex particles were investigated. Based on the recipe of 30 mM SDS to the volume of water, 2 wt% AIBN and 5 wt% RhBUEA to the total monomers, the sensing properties of the resultant latex and its film were studied. Both the latex and the latex film displayed the noticeable color change, high sensitivity, superior selectivity, and anti-interference properties towards Fe3+ over other metal ions in aqueous solution. The detection limits of the latex and the latex film were 0.122 and 0.208 μM, respectively. Furthermore, the film sensor exhibited good recyclability thanks to the off-on switch, possessing the potential as a portable and reversible chemosensor for the naked-eye detection of Fe3+.