Self-calibrated fluorescent probe resembled as an indicator of the lysosomal phosphatase pertaining to the cancer cells

A self-calibrated fluorescent probe Lyso-Phos has synthesized followed by a straightforward synthetic pathway. Lyso-Phos acts as an indicator for lysosomal phosphatase. Its photophysical property including cellular imaging was described. Lyso-Phos showed ratiometric UV-Vis- absorption changes from lambda(abs) 370 nm to lambda(abs) 450 nm in the presence of alkaline phosphatase (ALP). On the other hand, fluorescence intensity lambda(em) 560 nm of Lyso-Phos has increased around 45-fold in the presence of ALP. The probe Lyso-Phos was found to be highly chemoselective toward the phosphatase compared with other ubiquitous entities in cellular milieu. The non-toxic nature of the Lyso-phos has accounted by observing higher cell viability in prostate cancer- LnCap, fibrosarcoma HT1080 and normal mouse embryo fibroblast NIH3T3 cells. Further, the probe Lyso-Phos was utilized for tracking of cellular phosphatase in live-cells. Lyso-Phos enabled to track cellular phosphatase by the extent of fluorescence labeling of LnCap cells which showed reasonable uptake efficiency in the presence of Lyso Phos as indicated by the intracellular fluorescence. The phosphoester bond in the probe was cleaved by intracellular alkaline phosphatase leading to turn on fluorescence of the fluorescent probe Lyso Phos. Finally, cellular co-localization with Lyso-Tracker empowered our speculation that Lyso-Phos can track endogenous phosphatase in the lysosomes. Altogether these findings suggest that Lyso-Phos would be powerful probe to detect phosphates in cancer cells.