A fluorescent polyurethane foam based on rhodamine derivative as Fe(III) sensor in pure water

Rhodamine salicylaldehyde was synthesized, and its structure was determined using Fourier transform infrared spectroscopy, 1H NMR analysis as well as electrospray ionization mass spectrometry. Then a fluorescent polyurethane foam was obtained via incorporation of the prepared rhodamine salicylaldehyde, and the fluorescence sensing behavior for Fe3+ was systematically investigated. Results showed that the fluorescent polyurethane foam produced higher fluorescence in the presence of Fe3+ in pure water, due to the coordination for Fe3+ binding leading to ring‐opened amide form. The limit of detection was calculated to be 1.64 × 10−6 mol L–1. This fluorescent polyurethane foam can also recognize Fe3+ with good selectivity. © 2021 Society of Industrial Chemistry. A fluorescent polyurethane foam based on a rhodamine derivative was synthesized, which can serve as an Fe3+ sensor in pure water.