| Cancer is a great threat to human life,but the diagnosis and treatment of cancer is still one of the difficulties and hot spots in the biomedical field.In recent years,some biomarkers that are overexpressed or underexpressed in tumor cells have attracted wide attention from researchers.Studies have shown that these biomarkers usually participate in many channels in the life cycle and are closely related to the occurrence,development and treatment of tumor diseases.Therefore,the analysis and detection based on such markers have increasingly become the focus of biological research and clinical analysis.In the existing detection methods,small molecule fluorescent probes have been successfully applied to the detection of various biological targets due to their advantages such as structural adjustability,high detection sensitivity,non-destructive rapid analysis and real-time detection,and have shown great potential in the detection of trace amounts of bioactive substances and fluorescence imaging applications.NAD（P）H:quinone oxidoreductase isozyme 1（NQO1）,an important enzyme.On the one hand,NQO1 plays an important role in cellular Redox and signaling pathways,which can reduce the two electrons of quinones and effectively relieve quinone poisoning in normal organisms.On the other hand,the studies had also been demonstrated the high concentration level of NQO1 in many tumor cells,which is therefore considered as a cancer marker.The enzyme is sensitive to the environment as well as the concentration is very low in the early stage of the disease.It is of great significance to study the expression level of NQO1 in different cells and to conduct highly sensitive real-time activity detection and imaging of NQO1 in complex organisms for disease diagnosis and clinical analysis.Similarly,H2S,the third important signal transmitter gas molecule after CO and NO,is also regarded as an important biomarker.Studies have shown that the concentration is closely related to many diseases such as ischemic injury,Alzheimer’s disease,arteriosclerosis,breast cancer,liver cancer and so on,and the concentration varies greatly in different pathological models.As a key fulcrum for balancing health and disease in human physiology,the application of real-time activity detection and imaging of H2S in disease models has practical clinical significance for better understanding of related diseases and developing new approaches to drug therapy.This paper mainly focused on the above two biomarkers and carried out the following work:Chapter 1.IntroductionIn this chapter,the sensing mechanism of small molecule fluorescence probes were briefly discussed,and the recent progress in detection,imaging and application of NQO1 and H2S near infrared fluorescence probes in living tissues were reviewed.Finally,on this basis,the research significance and content of this topic were expounded.Chapter 2.Therapeutic monitoring of cervical cancer guided by NQO1-activated near-infrared fluorescent probe.Based on the significance of studying the activity of NQO1 for cancer discovery and treatment,we designed and synthesized NOQ1 targeting activated NIR probe Cy MT by selecting hemicyanine skeleton as the parent of fluorophore based on the specific recognition ability of trimethylquinone propionate group to NQO1.When activated by NQO1,Cy MT turned on NIR fluorescence at 725 nm,showing high sensitivity,good selectivity and excellent stability.NQO1 detection in living cells and vivo tissues demonstrated the excellent imaging ability of Cy MT to effectively distinguish normal cells from tumor cells.In addition,due to the killing ability of dual-coumarin drugs on tumor cells,we conducted real-time visual monitoring of the activity level of NQO1 in tumor mice during therapy through fluorescence imaging mode.The change of the fluorescence intensity indicated the change of NQO1 activity during therapy,indicating the progress of therapeutic effect.Therefore,Cy MT is an effective tool for the specific detection of NQO1 in living tissues.Chapter 3.An activated near-infrared fluorescence probe based on oxyxanthene derivatives was used for H2S detection.The spiral structure of oxanthracene derivatives has two modes of"closed"and"open"in different environments,which can be used as a good near infrared fluorescence emitting group.In this chapter,a new NIR probe Rh-N3 was designed and synthesized to detect the activity of H2S in tumor cells by selecting helicoxanthracene as fluorophore and utilizing the reducing ability of H2S to azide compounds.The results showed that Rh-N3 could be selectively activated by H2S and emit high fluorescence at720 nm,with rapid response,high sensitivity（detection limit 0.21μM）,and large Stokes shift（100 nm）.Rh-N3 could remain stable under long time laser irradiation and different p H solution environment monitoring,had good photostability and acid and alkali resistance,and the response to H2S was not affected by external temperature.In addition,the probe could be applied to the imaging detection of exogenous and endogenous H2S in cells,which had potential significance for the study of H2S in vivo. |
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