Synthesis of 2D fluorescent polyaniline derivatives as multifunctional fluorescent chemosensor

Polyaniline (PANI) has been widely studied and applied due to its easy-to-obtain raw materials, excellent electrochemical performance and high environmental stability. Here, we present a general synthetic strategy for preparing two-dimensional (2D) fluorescent PANI derivatives. The double bonds are used as a conjugated spacer between benzene rings in PPED and PPBA. The work breaks through the limitation of PANI derivatives are non-emissive in solutions. The fluorescence quantum yields (Ф f ) of PPED and PPBA are 2.5% and 1.5%, respectively. PPED and PPBA show highly selective and sensitive detection of iron ion (Fe 3+ ), copper ion (Cu 2+ ) and hydrochloric acid (HCl). It is worth noting that the detection limit of PPED for Fe 3+ is 35 nM. In addition, the theoretical study indicates that the introduction of double bonds in PPED and PPBA greatly enhances their conjugation extent. The results demonstrate that we provide a powerful method for the preparation of highly sensitive fluorescent chemosensors based on 2D PANI derivatives. Graphical