Design,synthesis And Biological Imaging Research Of Two Small Molecule Fluorescent Probes For Detecting Effectors Of Oxidative Stress

Fluorescent probes are generally used in environmental monitoring,disease diagnosis,biological imaging and other fields.The response mechanism of the probe is due to the structural change between the recognition group in the molecular structure and the substance to be detected,which causes the original fluorescence intensity of the probe changing.Among them,small molecule fluorescent probes have the advantages of high sensitivity,low toxicity,strong selectivity and simple manipulation.With the development of modern imaging technology and instruments,it HSA become one of the important contemporary chemometric imaging tools.In this paper,we designed and synthesized the probe T and the probe OXO-ZX,using the common oxidative stress effectors hypochlorite(Cl O~-)and peroxynitrite(ONOO~-)as the detected For the subject,we confirmed the molecular structure of the probe by NMR and mass spectrometry,and verified the fluorescence imaging characteristics of the probe based on the results of multiple in vivo and in vitro activity experiments.Probe T is based on the quinolinaldehyde structure,and uses a redox mechanism to remove some of the groups to cause fluorescence quenching.The probe T HSA the advantages of high sensitivity and rapid response.The detection limit is 0.426?M.The fluorescence quantum yield is calibrated with rhodamine dye to 0.7%.After contact with Cl O~-,the fluorescence decreases immediately,making it difficult for the instrument to detect and capture intermediate products.Through in vitro anti-interference experiments,we proved that the probe T HSA strong anti-interference under the influence of other zwitterions,amino acids,proteins and reactive oxygen species.In addition,imaging experiments on cells and plants show that the probe T can better detect changes in the concentration of internal and external sources of Cl O~-,and it can be applied to the detection of Cl O~-in living plants.In summary,this study provides basic evidence for the relationship between the chloric acid channel disorder in the mutant roots of Arabidopsis thaliana and the effect of hypochlorous acid absorption.In addition,the response mechanism of our designed and synthesized probe OXO-ZX is similar to that of the above-mentioned probe.Contact with the test substance triggers an oxidation-reduction reaction,which causes the heterocyclic cleavage to weaken the original fluorescence of the probe.The results of the in vitro activity test prove that the probe OXO-ZX HSA good stability and is not interfered by zwitterions.The ratio of the fluorescence intensity change of probe OXO-ZX to the concentration change rate of ONOO~-showed a trend of slowing first,then fast and then slowing down.According to the linear fitting formula of the standard concentration curve,the detection limit is 0.64?M.In cell and plant imaging experiments,the probe OXO-ZX exhibits excellent biological adaptability,and can participate in the process of Arabidopsis root absorption and tube transport in the rhizome.Our method of using small-molecule fluorescent probes for plant imaging provides a new detection method for studying the bioaccumulation effects of pollutants in plants and the absorption and transportation of nutrients.