Construction And Biomedical Application Of Novel Mercury Ion Fluorescent Probes

Aim:Mercury ion(Hg²⁺),as one of the most common harmful heavy metal ions,widely exists in nature.It enters the human body through the food chain and accumulates continuously in the body,thereby causing various diseases.Therefore,the development of rapid,high-sensitivity quantitative detection of Hg²⁺in the environment and in vivo has important research significance for environmental monitoring,food safety and medical diagnosis.Based on the advantages of fluorescence sensing including high sensitivity,good selectivity and real-time imaging,we have carried out a series of related studies to realize the sensitive detection of Hg²⁺.Method:With the tools of organic synthesis,optical property characterization,confocal imaging and other biological techniques,the new constructed probes were evaluated for detecting Hg²⁺.Results and conclusions:（1）By introducing a large planar D-A-D conjugated structure of oxonium ions,a fluorescent probe SPOM with good water solubility was constructed.The introduction of a thiocarbonyl group at the recognition site with photoinduced charge transfer（PET）effect reduced its own background fluorescence.After the probe responded to Hg²⁺,the PET effect was turned off,and the fluorescence was significantly enhanced（～75 folds）.The qualitative and quantitative detection of low concentrations of Hg²⁺in urine,tap water,and living cells was successfully achieved.（2）A novel fluorescent probe HTM was constructed by cleverly combining aggregation-induced emission（AIE）,excited state proton transfer（ESIPT）and PET effects.This probe presents specific and high sensitivities for detecting Hg²⁺（detection limit=1.65n M）,and was successfully applied to detect Hg²⁺in seafood,water samples,and living cells.（3）The innovative combination of the clinical antidote2,3-dimercaptopropanol with a near-infrared AIE fluorophore through a click reaction constructed a dual-function probe BALHM with detoxification and detection of Hg²⁺.This probe showed formidable advantages in detection time（<1 min）,low detection limit（0.49 n M）and strong detoxification ability,which provided a new strategy for the construction of a multifunctional Hg²⁺probe integrated with diagnosis and treatment.These studies provided new ideas for sensitive detection and detoxification of harmful heavy metal ions.This dissertation contains 84 figures,9 tables and 150 references.