Self-assembly of pyrene boronic acid-based chemodosimeters for highly efficient mercury(II) ion detection

A new chemodosimeter consisting of pyrene and boronic acid (1) for the detection of Hg²⁺ ions is described. The amphiphilic nature of 1 leads to self-assembly in aqueous solution and the high electron density throughout the aggregated pyrene units provides an outstanding platform for energy and electron transport. Self-assembled 1 exhibits a selective and sensitive fluorescence response to Hg²⁺ ions, where the Hg²⁺ ion allows a fast transmetallation of 1, which drastically reduces its fluorescence. The Stern-Volmer (SV) quenching constant for the fluorescence quenching of self-assembled 1 by Hg²⁺ ions is approximately 1.8 × 10⁶ M^?1, and Hg²⁺ ions can be sensed with a detection limit of 6.6 × 10^?9 M. In addition, self-assembled 1 exhibits excellent sensing performance at nano-molar concentration levels for Hg²⁺ ion contamination of tap water, fresh water, and seawater.