A zinc-dipicolylethylenediamine modified near infrared fluorophore for sensing of ATP.

The development of fluorescent probes for sensing of anions in biological environments is still a demanding task. Due to the structural versatility of biological active anions there are many challenges to cope with compared to fluoroionophores for the determination of metal cations. This concerns particularly the design of the recognition element, which has to provide a selective response, preferably unaffected by alterations of pH and ionic strength. Polyphosphate anions such as ATP are interesting targets in bioanalysis because they are involved in many enzymatic reactions and bear versatile biological functions. Zinc dipicolylamine complexes attached to fluorophores have been turned out to be promising candidates for ATP sensing with sufficient sensitivity and selectivity. We now report the first NIR probe that responds to ATP based on a zinc dipicolylethylenediamine receptor. It shows a "turn-on" fluorescence behavior which is selective to other polyphosphate species even at high ionic strength of the sample solution.