A Borondipyrromethene-based Zn~2+ Fluorescent Probe: Synthesis And Application

Measurement of Zn2+ is essential but challenging due to the biological significance and the interference of other metals in biological systems. Herein, we report a novel borondipyrromethene-based Zn2+ fluorescent probe BODPAQ.The chelators in BODPAQ,2,2'-Dipicolylamine (DPA) and 8-aminoquinoline (AQ), coordinate to Zn2+ in a synergic manner. As a result, BODPAQ displays high Zn2+ selectivity with a dramatic enhanced emission accompanied by a notable hypsochromic shift due to the binary inhibited effect of PET and ICT mechanism, enabling the detection of Zn2+ by both ratiometric and normal turn-on fluorescence methods in acetonitrile. Interestingly, the sensitivity of BODPAQ toward Zn2+ changes as varying the compositions of Buffer solutions. In 3-Morpholinopropanesulfonic acid (MOPS) Buffer aqueous solution (50%CH3CN), BODPAQ displays the highest sensitivity for Zn2+, while in Citrate-Phosphate Buffer, BODPAQ shows no response to Zn2+To improve the Zn2+ specific amplified fluorescence in aqueous solutions, chelators with high affinity for Zn2+ should be introduced into borondipyrromethene core. Strategy like introduction of N, N, N'-tri(pyridine-2-ylmethyl)ethane-1,2-diamine (TPEA) instead of DPA is in progress.