Synthesis And Bioimaging Applications Of The Novel Lysosome-Targeting Fluorescence Probes

Lysosomes are one of the most important acidic suborganelles（pH 4.5-5.5）in eukaryotic cells,which play an important role in metabolish,cell metabolism and apoptosis.And the abnormal function of lysosomes is often accompanied by the occurrence of related diseases.Fluorescence analysis has become a research hotspot for the detection of active substances in lysosomes with its advantages of simple operation,high sensitivity and real-time imaging.Given that,three water-soluble fluorescent probes targeting lysosomes were synthesized.（1）HPU-F1 was a novel small molecule fluorescent probe for specific recognition of hypochlorous acid（HCl O）,which exhibited a notable deep-red emission at 640 nm in pure water.This deep-red emission was specifically quenched by adding Cl O^-.The probe HPU-F1 had the advantages of short response time（within 10 s）,high sensitivity（0.012μM）,and wide working p H range（1.0-12.0）.Moreover,HPU-F1 was successfully utilized to monitor ClO^-in lysosomes of He La cells and in zebrafish.（2）HPU-F2 was a small molecular fluorescence probe for detecting CEs activity based on cyanine skeleton and acetyl group as recognition site.The emission at 510 nm of the probe in neat aqueous solution was partially quenched and red-shifted to 580 nm after adding CEs.More importantly,the probe was successfully applied to detect and image carboxylesterase activity in zebrafish.（3）HPU-F3 was a fluorescence probe for specific recognition of Hydrogen sulfide （H₂S）constructed by introducing 2,4-dinitrophenyl ether group into cyanine dye.The probe had the advantage of rea-time response to H₂S detection.In addition,HPU-F3 also had the function of lysosomal targeting,and the co-staining coefficient was up to 0.94.Based on the above advantages,the probe was successfully applied for tracing H₂S in the lysosomes of MCF-7 cells and in zebrafish.