A Monostyryl Boradiazaindacene (BODIPY)-based lanthanide-free colorimetric and fluorogenic probe for sequential sensing of copper (II) ions and dipicolinic acid as a biomarker of bacterial endospores.

A new catechol-substituted monostyryl boradiazaindacene (BODIPY)-based lanthanide-free colorimetric and fluorogenic probe was developed for the sequential detection of Cu2+ ions and dipicolinic acid (DPA), a distinctive biomarker of bacterial endospores, with high sensitivity and selectivity. In the presence of Cu2+ ions, the blue solution of the probe changes to cyan and the fluorescence is quenched, however, the cyan color changes to blue immediately and the fluorescence is restored on contact with DPA, resulting from competitive binding of DPA that interact with Cu2+ ions. A practical application by using Geobacillus stearothermophilus spores was further studied and as low as 1.0 x 105 spores were detected.