Novel Schiff base derivatives for the detection of one-to-multi metal ions and tracking the live cell imaging

The development of fluorescent turn-on receptors for the selective and sensitive detection of particular ions is one of the active area of research. The recognition and monitoring of biologically important metal ions via fluorescence turn-on mechanism is of utmost important, since the process of tracing metal ions in organelles have both advantages and drawbacks. Schiff base-based chemosensors have gathered specific attention because of their fascinating optical properties, excellent thermal stability, and also easiness in synthesis. Numerous distinct fluorescence turn-on probes have already been described. In this regard, the study of the mechanistic insights, design and principle, applications of Schiff base-based fluorescent probes in bio-imaging and selective and sensitive detection of one-to-one and one-to-multi metal ions have received lot of attention. There are several chemosensors developed by incorporating fluorescent organic molecules such as rhodamine, fluorescein, coumarin, anthracene, quinoline, BODIPY, dansyl, and naphthalimide to the Schiff bases, which found to be better chemosensors for particular metal ions and can also be utilized for one-to-multi metal ions. Comparatively, the development of straightforward, effective, and functionalized fluorescence probes showing biological activity and multi-analyte response is difficult from the perspectives of economic value and real-world applications. Recently, there have been lots of reports of one-to-multi type fluorescence probes made for various metal ions. This review strongly focused on the broad overview of fluorescent Schiff base probes for the selective and sensitive detection of one-to-multi metal ions via fluorescence turn-on mechanism and also their cellular imaging applications which will provide readers a better understanding about the necessity of monitoring more than one metal ions at a time considering their importance in human health and disease. Finally, it is addressed how fluorescent Schiff base sensors can be used to detect metal ions in the future.