Building carbazole-decorated styrene–acrylic copolymer latexes and films for iron(III) ion detection

Abstract The detection and sensing of trace iron(III) ions is a crucial but challenging task. Herein, we report a facile strategy to build carbazole-based copolymer latexes and films via semi-continuous emulsion copolymerization for the selective detection of iron(III) ions. Carbazole-decorated styrene–acrylic copolymer latexes were synthesized by the copolymerization of styrene, acrylates, and N-vinylcarbazole (NVCz) under mild conditions. The effects of the comonomer composition on emulsion copolymerization and the properties of the copolymer latexes/films were studied. The obtained copolymer latexes exhibit homogeneous spheres through regulating the NVCz content from 0 to 5 wt%. Notably, the copolymers exhibited the characteristic emission of carbazole in both latex and solution form, and the emission intensity can be easily tuned by varying the NVCz content. Surprisingly, higher carbazole content led to differences in the excitation and emission peaks of the latex and solution, resulting from the formation of an excimer in the latex. Moreover, the fluorescence of the latex and film can be selectively and effectively quenched by trace amounts of iron(III) ions in aqueous media. The limits of detection (LODs) of the copolymer latex and film were 1.90 and 1.71 μM, respectively. These results illustrate that the carbazole-decorated styrene–acrylic copolymer prepared employing a facile, inexpensive, scalable and environment-friendly procedure can be used to fabricate high-performance photoelectric devices and high-efficiency fluorescent sensors.