A Zn2+ fluorescent sensor derived from 2-(pyridin-2-yl)benzoimidazole with ratiometric sensing potential

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