A Zn2+ Fluorescent Sensor Derived from 2-(Pyridin-2-yl)benzoimidazole with Ratiometric Sensing Potential

A fluorescent Zn2+ sensor based on the 2-(2'-pyridinyl)benzoimidazole (2-PBI) fluorophore has been devised by incorporation with a Zn2+ ionophore, bis(pyridin-2-ylmethyl)amine. The sensor (PBITA) demonstrates a Zn2+-specific emission shift and enhancement with a 1:1 binding ratio. Due to the Zn2+-induced coplanation of 2-PBI via reversion/rotation, PBITA is shown to behave as a ratiometric sensor. The intracellular Zn2+ imaging ability of the sensor has been tested in HeLa cells using a confocal microscope.