Photoluminescence imaging of Zn(2+) in living systems

Zn(2+) plays essential roles in various physiological processes in living systems, and the investigation of Zn(2+) related physiology and pathology has attracted considerable interest. Because photoluminescence (PL) imaging possesses distinct advantages, such as high sensitivity and non-invasiveness, and excellent temporal and spatial resolution, it has become a powerful tool for the real time monitoring of Zn(2+) distribution, uptake, and trafficking. Over the last two decades, great efforts have been devoted to PL Zn(2+) imaging in living systems, which proved the Zn(2+) fluctuations in physiological processes and the temporal-spatial distribution of labile Zn(2+) as well as the localization of labile Zn(2+) pools. Advances in PL techniques, such as fluorescence microscopy, confocal fluorescence microscopy, two photon fluorescence microscopy, lifetime based techniques and luminescence optical imaging systems, have made remarkable contributions in tackling major challenges in Zn(2+) PL imaging. With the rational design and proper use of fluorescent sensors, Zn(2+) imaging in various cell lines, organelles, tissues, organs and living animals has been realized, which was shown to be crucial in elucidating the biological and physiological roles of labile Zn(2+).