A red fluorescent probe, PFB, is designed and synthesized, which presents several remarkable features including a large Stokes shift (85 nm), long emission wavelength, high photostability and good biocompatibility. PFB also displays the solvent-dependent effect, which is verified by the density functional theory (DFT) calculations. Additionally, PFB can act as a fluorescent probe for cellular imaging with high uptake efficiency and highly sensitive detection toward RNA under low optimum concentration (1 μM), which enables it to achieve cancer cell tracing in vitro and tumor growth monitoring in vivo. The results of real-time tracking experiment reveal that PFB can be traced in stained HepG-2 cells for 11 generations and monitor tumor growth for 18 days. This work highlights the potential application of PFB as a promising alternative to the commercial RNA fluorescent probes.

设计并合成了红色荧光探针PFB，该探针具有几个显着特征，包括大的斯托克斯位移（85 nm），长的发射波长，高的光稳定性和良好的生物相容性。PFB还显示出溶剂依赖性效应，该效应已通过密度泛函理论（DFT）计算得到验证。此外，PFB可以用作细胞成像的荧光探针，在低最佳浓度（1μM）下具有高吸收效率和对RNA的高灵敏度检测，从而使其能够实现体外癌细胞追踪和体内肿瘤生长监测。实时跟踪实验结果表明，PFB可在染色的HepG-2细胞中追踪11代，并监测肿瘤生长18天。这项工作强调了PFB作为商业RNA荧光探针的有希望替代方法的潜在应用。