A Selective Fluoroionophore Based on BODIPY-Immobilized Silica Nanoparticles for Cu<SUP>2+</SUP> Ion

A new fluorescent receptor based on BODIPY-immobilized silica nanoparticles (BODIPY-SiO2), BODIPY-SiO2, was prepared. The BODIPY-SiO2 exhibits a high affinity and selectivity for Cu2+ over competing metal ions in water. Upon the addition of Cu2+, an overall emission change of 5-fold was observed. On the other hand, except Cu2+, no significant fluorescence intensity changes were observed in the experiments using other metal ions. Interestingly, the increase in fluorescence intensity upon exposure to Cu2+ was fully reversible, as the addition of strong base to the acidic solution reversed this effect. Furthermore, we found that the BODIPY-SiO2, can remove 75% of Cu2+ ion from Cu2+ solution. Thus, the BODIPY-SiO2 can be potentially useful and effective agents of separation for selective and rapid removal of Cu2+.