Design,Synthesis And Properties Of Reactive Rhodamine Derivatives Near-infrared Fluorescent Probes

In the cell microenvironment,the increased levels of reactive oxygen radicals(ROS)are mainly caused by oxidative stress caused by redox imbalance.In order to avoid oxidative stress,cells will up-regulate the synthesis of antioxidant molecules such as glutathione(GSH)to eliminate excessive ROS.In addition,the heavy metal element copper is also involved in many redox processes in cells.Excessive copper will increase the level of ROS and cause oxidative stress and apoptosis.In the tumor microenvironment,oxidative stress caused by reactive oxygen free radicals is very common.Near-infrared biofluorescence imaging technology has received widespread attention as a high-sensitivity and high-selectivity detection method,but its response mechanism,fluorescence effect,and complex biological environment applications are still problems that need to be resolved.Therefore,the design of efficient and sensitive near-infrared reactive fluorescent probes has important theoretical significance and potential application value for tumor biology research.In this study,three near-infrared reactive fluorescent probes based on rhodamine derivatives were designed and synthesized to detect the heavy metal elements Cu(?),glutathione(GSH)and hypochlorous acid/hypochlorite(HClO/ClO^-).Due to the spirolactam structure of rhodamine derivatives,the probe itself has almost no fluorescence or only a small amount of fluorescence.After interacting with the active species,the spiro ring opens and the fluorescent group is released,thereby generating strong emission fluorescence to detect the target substance.In addition,spectroscopic detection and cell-level research were carried out on the three probes.The main research contents are:(1)Synthesize three kinds of rhodamine derivative fluorescent probes by chemical means,and use ~1H NMR,¹³C NMR,HRMS to characterize and identify the target probes;(2)By fluorescence spectrophotometer To study the optical properties of the probe,including its emission spectrum,concentration dependence,kinetic response,anti-interference ability,p H and temperature stability,etc.;(3)The MTS method was used to evaluate the toxic effect of the probe on Hela cells And by combining with laser confocal technology,the probe's live cell imaging experiment was successfully realized.The above experimental results show that the three fluorescent probes all have near-infrared fluorescence emission and large Stokes shift values,and they all have high selectivity and stability;cell-level experiments show that the probes Both of them have low toxicity,and they all have the ability to achieve live cell imaging.In addition,HPLC was used to study the Cu(?)response mechanism.Therefore,this study provides a reliable way to efficiently and sensitively realize the early diagnosis and treatment of tumors by visually and quantitatively determining the active substances Cu(?),GSH and ROS in the cells,and also for the detection of sensitive substances in the tumor redox microenvironment.It has important research significance.