A novel fluorescent probe for zinc ion based on boron dipyrromethene (BODIPY) chromophore

ZnAB has the combined structure of N,N-bis(2-pyridylmethyl)ethylenediamine as a specific chelater for Zn(2+) and 1,3,5,7-tetramethyl-8-phenyl-boron dipyrromethene as a fluorophore. Complexation of ZnAB with Zn(2+) produces a remarkable enhancement of fluorescence intensity. ZnAB has the advantages of less sensitivity to solvent polarity and pH than fluorescein-based Zn(2+) probes. Furthermore, it is not influenced by other cations, such as Na(+), K(+), Ca(2+), and Mg(2+), which exist at high concentrations under physiological conditions, even at 2.5 mM. The results show that ZnAB is a Zn(2+) probe suitable for biological applications.