Synthesis and bioimaging of mitochondria targeted nitroreductase-responsive fluorescent probe

Malignant tumors are a significant threat to human well-being, necessitating rapid diagnosis and treatment. Mitochondria play a crucial role in tumor metabolism, the regulation of redox and calcium homeostasis, and transcription regulation. As a result, researchers have targeted mitochondria as a potential avenue for the development of new anticancer drugs and detection probes. Fluorescent probes have gained popularity in chemical biology due to their remarkable sensitivity, rapid response, stability, and simplicity. In this study, we devised a mitochondrial fluorescent probe called TPP-TPA-PBN, which responds to nitroreductase found at high levels in tumors. The optical properties of TPP-TPA-PBN indicate favorable water solubility and responsiveness to nitroreductase. Additionally, the MTT assay demonstrated the high safety of TPP-TPA-PBN for cells. Notably, TPP-TPA-PBN exhibited distinctive fluorescence in tumor cells, as opposed to other cells, with exceptional co-localization properties with mitochondria. Furthermore, the fluorescence intensity augmented with concentration and time. Consequently, this investigation established the immense potential of TPP-TPA-PBN as a mitochondrial fluorescent probe that responds to nitroreductase, therefore facilitating tumor detection. Schematic diagram for mitochondrial imaging of tumor cells.