[5]Helicene-Scaffold Fluorescence Sensing for Selective Detection of Au³⁺ Ions and Gold Nanoparticle

A new quenching fluorescence sensor (MDP) with high productivity was easily synthesized from a [5]helicene anhydride derivative and propargyl bromide. This MDP sensor has significant photophysical properties, including high fluorescence emission and a large Stokes shift, and it exhibits selectivity and an excellent detection response in distinguishing Au³⁺ ions from interfering metal ions in aqueous solution. The limit of detection of the sensor were determined to be 0.16 µmol L^-1 or 32.0 ppb. Stoichiometric binding between the MDP and Au³⁺ ions was found to occur at a 1:2 ratio. Additionally, the MDP sensor shows an ability to detect gold ions in real water samples and recognize gold nanoparticles (AuNPs), which invites its further application in biological and environmental systems.

Keywords:
fluorescence sensor; [5]helicene; gold ions; gold nanoparticle