Facile one-pot synthesis of novel water-soluble fluorescent hyperbranched poly(amino esters)

Two kinds of water-soluble fluorescent hyperbranched poly(amino esters) were first synthesized by a convenient one-pot approach via the A₂ + B₃ Michael addition reaction of trimethylolpropane triacrylate and aliphatic diamines. Their structures and optical properties were determined by FTIR, NMR, GPC, UV-vis, and fluorescence spectra. The hyperbranched poly(amino esters) in aqueous solutions and PVA films state showed strong blue fluorescence when these polymers were excited by a UV lamp. In addition, it was found that their fluorescence exhibited a pH-dependent behavior. It was also noteworthy that the fluorescence could be changed by adding metal ions. The fluorescence of the polymer could be quenched when the concentration of Hg²⁺ and Fe³⁺ reached at 10^-2 mol L^-1. Therefore, the prepared hyperbranched poly(amino ester) is a promising ion probe for detecting Hg²⁺ and Fe³⁺.