engleski

NOVEL NAPHTALIMIDE–BASED “ON-OFF” FLUORESCENT PROBES FOR DETECTING Hg2+ AND Cu2+ IONS

Fluorescence-based optical sensors and chemosensors provide a simple, rapid, low-cost but highly sensitive method for measurement of metal ions at very low concentrations.[1]Photoinduced electron transfer (PET) sensors comprising 1, 8-naphtalimides are particularly popular for molecular fluorescent “switch” designs.[2] We characterised two novel 1, 8-naphthalimide-based fluorescent probes for Cu2+ and Hg2+. Different functional groups attached at the C-4 position in GJM-523 and GJM-525 (Figure 1a) show a notable effect on the optical properties in the presence of metal ions. The fluorescence quenching of the highly emissive compound GJM-523 (Figure 1c) is attributed to the formation of the 1:1 complex with either Cu2+ or Hg2+ (Figure 1d). The detection limits achieved with GJM-523 are in the subnanomolar range. GJM-525 forms a 1:2 complex with Hg2+ ions, which hinders the PET process and induces the fluorescence into the ON state (Figure 1b). The results show remarkable selectivity towards Hg2+ ions and a satisfactory limit of detection (Figure 1e).

1, 8-naphtalimide ; fluorescent probe ; metal sensor

nije evidentirano