Highly Selective Fluorescent Sensors: Polyethylenimine Derivatives of Triphenylamine and Coumarin for GTP and ATP Interaction via Fluorescence Lifetime Imaging Microscopy.

Chemical derivatives of polyethylenimine (PEI) receptors with either triphenylamine (TPA) or 7-hydroxy-4-methyl-coumarin (Cou) form stable complexes with adenine and guanine nucleotides in water. The host-guest complex modulation is found to be based on noncovalent molecular interactions such as π-π stacking and hydrogen bonding, which are dependent on the aromatic moieties attached to the polyaminic (PEI) backbone. acts as a chemosensor with a recognition driving force based on aggregation-induced emission (AIE), involving π-π interaction between the nucleic base and TPA.