Fluorescent probes have the potential to track multiple analytes or parameters of their microenvironments. Also, they have gained huge attention in the field of intracellular imaging, material defects tracking, disease diagnosis, and high-resolution sensing.
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However, the majority of the reported fluorophores could just detect one or a few parameters or analytes. Coming up with a flexible fluorescent probe for various microenvironmental monitoring is still a difficulty.
In a study reported in the journal Angewandte Chemie International Edition, the research group headed by Professor Weiguo Huang from Fujian Institute of Research on the Structure of Matter of the Chinese Academy of Sciences came up with a new class of configuration-induced multichromism fluorophores together with several responses to the external information.
Three phenanthridine-based fluorophores (that is, B1, F1, and T1 with 1D, 2D, and 3D molecular configurations, respectively) were designed and synthesized by the scientists. It has the potential to track several microenvironments. B1 and F1 with respective 1D linear and 2D planar molecular configurations displaying normal aggregation-caused quenching (ACQ) behavior, while T1 holds a dynamic saddle-shaped configuration acting as an AIEgen.
Also, the researchers discovered that these three fluorophores could efficiently react to the rigidity, viscosity, and aggregated state change of microenvironments. On making it get subjected to compression, all fluorophores provide red-shifted emissions with decent recoveries.
Especially, the emission peak of F1 transforms from 465 nm to 628 nm in going from 0.00 GPa to 17.50 Gpa. This displays an entire redshift of 163 nm and a fluorescence color evolution of blue, yellow, green, red, and orange resulting in an organic fluorophore-based full-color piezochromism.
Also, under external mechanical pressures, the scientists disclosed that the configurational variations of three fluorophores alter their photophysical properties. To profit from the relationship between photophysical properties and the applied pressure, the scientists studied the piezochromic luminescence properties of F1, B1, and T1 under controlled hydrostatic pressure through the use of a diamond anvil cell (DAC).
Furthermore, by manipulating the incubation time in live cell imaging, the scientists discovered that B1 primarily stains the cytoplasm, whereas F1 and T1 selectively concentrate in the cell nucleus, and the nucleus-targeting staining performance of F1 is better compared to the commercial 4′,6-diamidino-2-phenylindole (DAPI) probe.
This study offers a general design plan of adaptable fluorophores capable of sensing multiple analytes or parameters in varied microenvironments.
Huang, W., et al. (2023) Configuration-Induced Multichromism of Phenanthridine Derivatives: A Type of Versatile Fluorescent Probe for Microenvironmental Monitoring. Angewandte Chemie International Edition. doi.org/10.1002/anie.202219337.