Design,Synthesis And Performance Study Of Lysosomes-Targeted Carbazole-based Two-Photon Fluorescent Probe

Small molecule fluorescent probes have very broad development prospects in biological systems.We can use fluorescent probes to better understand the changes in the internal microenvironment of biological cells.The fluorescent signals of the probes will occur with changes in the internal environment of the cells.Variety.Small molecule probes have outstanding advantages in biological imaging,high sensitivity,and extremely low toxicity to cells,which is conducive to long-term cell monitoring.At the same time,we can properly design the probe to target different organelles and respond to different cellular environmental factors,such as polarity,viscosity,p H,etc.As a result,more people pay attention to fluorescent probes and gradually become an efficient and convenient analysis tool.Polarity is a very important index of the cell microenvironment,and cell activities and many physiological responses are closely related to it.Different states of cells correspond to different pathological and physiological activities.When the state of cells changes,the polarity will also change.Polarity,as an important parameter for observing cell state,has been shown to be closely related to many physiological processes,such as peptide aggregation,protein denaturation,membrane fusion,and enzyme conformational changes.Therefore,it is very important to realize the accurate detection of polarity,which will help people to understand the impact of many diseases on cells more clearly.Fluorescent probes with AIE properties have excellent biocompatibility and low toxicity to cells,and can complete precise organelle positioning in living cells,and have been increasingly used in cells.AIE fluorescent probes can also be lit in the aggregated state,can achieve high signal-to-noise ratio in situ detection,have a long retention time in living cells,can achieve long-term intracellular tracking,and have been widely used for cell imaging or Detect and analyze ions and small molecules in cells.(1)Designed and developed a fluorescent probe PLW,which can be used to detect polarity.Use the intramolecular charge transfer(ICT)mechanism to improve the speed and efficiency of the response to polarity,and strengthen the detection of lysosomal polarity.During the spectral test,we found that the probe PLW can form a better response to polarity when excited at 340 nm.Because of its low biological toxicity,the probe can be used for long-term monitoring of lysosomal polarity,and it also provides an effective tool for future polarity detection.(2)A fluorescent probe PLF that can target intracellular lysosomes was designed and synthesized using carbazole as a parent.In order to accurately locate the lysosome,a tetravinylpyridyl group is inserted into the probe PLF molecule,and the tetraphenylethylene group is used as the AIE group of the probe,and a larger conjugate system can be formed between each group.Because of the excellent properties of the carbazole group,good biocompatibility,strong fluorescence signal,and good optical stability,it is beneficial for the probe PLF molecules to penetrate the cell membrane into the cell interior.In biological testing,the PLF probe is used to achieve precise targeting of lysosomes.Through experimental data,we found that it has a huge space for development in the field of biological cell detection,which can become an ideal tool for lysosome detection.