Importance of BODIPY-based Chemosensors for Cations and Anions in Bio-imaging Applications

Background: Chemosensor compounds are useful for sensitive, selective detection of cations and anions with fluorophore groups in an attempt to develop sufficient selectivity of the sensors. Although familiar fluorescent sensors utilize inter-molecular interactions with the cations and anions, an extraordinary endeavor was executed in the preparation of fluorescent-based sensor compounds. 4,4-difluoro-4- bora-3a,4a-diaza-s-indacene (BODIPY) and its derivatives were first used as an agent in the imaging of biomolecules due to their interesting structures, complexation, and fluorogenic properties. Among the fluorescent chemosensors used for cations and anions, BODIPY-based probes stand out, owing to the excellent properties such as sharp emission profile, high stability, etc. In this review, we emphasize the BODIPY-based chemosensor compounds, which have been used to image cations and anions in living cells because of their biocompatibility and spectroscopic properties. Methods: Research and online contents related to chemosensor online activity are reviewed. The advances, sensing mechanisms and design strategies of the fluorophore, exploiting selective detection of some cations and anions with BODIPY-based chemosensors, are explained. It could be claimed that the use of BODIPY-based chemosensors is very important for cations and anions in bio-imaging applications. Results: Molecular sensors or chemosensors are molecules that show a change that can be detected when affected by the analyte. They are capable of producing a measurable signal when they are selective for a particular molecule. Molecular and ion recognition is important in biological systems such as enzymes, genes, environment, and chemical fields. Due to the toxic properties of many heavy metal ions, it is of great importance to identify these metals due to their harmful effects on living metabolism and the pollution they create in the environment. This process can be performed with analytical methods based on atomic absorption and emission. The fluorescence methods among chemosensor systems have many advantages such as sensitivity, selectivity, low price, simplicity of using the instrument and direct determination in solutions. The fluorescence studies can be applied at nanomolar concentrations. Conclusion: During a few decades, a lot of BODIPY-based chemosensors for the detection of cations and anions have been investigated in bio-imaging applications. For the BODIPY-based fluorescent chemosensors, the BODIPY derivatives were prepared by different ligand groups for the illumination of the photophysical and photochemical properties. The synthesized BODIPYbased chemosensors have remarkable photophysical properties, such as a high quantum yield, strong molar absorption coefficient, etc. Moreover, these chemosensors were successfully implemented on living organisms for the detection of analytes.