Enhancing or Quenching of a Mitochondria-Targeted
AIEgens-Floxuridine Sensor by the Regulation of pH-Dependent Self-assembly,
Efficient Recognition of Hg2+, and Stimulated Response
of GSH
posted on 2023-12-13, 15:33authored byYating Zeng, Ziyan Wang, Linyu Zeng, Hai Xiong
Biocompatible
fluorescent probes have emerged as essential tools
in life sciences for visualizing subcellular structures and detecting
specific analytes. Herein, we report the synthesis and characterization
of a novel fluorescent probe (TPE-FdU), incorporated with hydrophilic
2′-fluoro-substituted deoxyuridine and hydrophobic ethynyl
tetraphenylethene moieties, which possessed typical aggregation-induced
emission (AIE) behavior. In comparison to the TPE-FdU (pKa 7.68) treated in neutral conditions, it performed well
at pH 4, exhibiting an enhanced 450 nm emission signal of approximately
four times stronger. As the pH value was increased to 10, the fluorescence
intensity was completely quenched. The TEM images of TPE-FdU in an
acidic environment (nanospherical morphology, AIE enhance, pH = 4)
and in a basic environment (microrods, fluorescence quenching, pH
= 9) revealed that it was a pH-dependent self-assembled probe, which
was also illustrated by the interpretation of the NMR spectrum. Furthermore,
the TPE-FdU probe exhibited a specific response to trace Hg2+ ions. Interestingly, the quenched fluorescence of the TPE-FdU probe
caused by Hg2+ can be recovered by the addition of GSH
due to the formation of the Hg–S bond being released away.
MTT assay and CLSM images demonstrated that TPE-FdU was nontoxic and
selectively visualized in the intracellular mitochondria. These results
contributed to the development of advanced fluorescent probes with
diverse applications in cell imaging, environment protection, and
biomedical research.