Construction Of Nanofluorescence Sensing Platform And Application Of Analysis Of Disease-Related Molecules

Objective:The cross-integration of multidisciplinary innovative technologies for molecular diagnosis and nanomaterials will help to further clinical disease-related research so as to better protect our human health.Furthermore,fluorescence-sensing technology is an emerging technology in the field of molecular diagnostics.Therefore,in order to provide a new fluorescence sensing strategy for ralated molecular detection of infectious diseases,aptamers were combined with carbon nitride nanosheets（CNNS）and molybdenum disulfide nanosheets（Mo S₂NS）,respectively,for application to the analysis of cytokine Interferon-γand biotoxin Aflatoxin B1.Methods:（1）In the first chapter,based on a two-dimensional nanomaterial,namely CNNS,and recognition probe,namely IFN-γNucleic acid aptamers（Apt@IFN-γ）construct a fluorescent sensor.CNNS can rapidly quench the fluorescent dye modified on the Apt@IFN-γprobe because of Photoinduced Electron Transfer（PET）.When Apt@IFN-γexist in the reaction solution,we add IFN-γ,and Apt@IFN-γcan specifically recognize IFN-γand combine with it.Losing single-chain structure Apt@IFN-γwill keep the compound of Apt@IFN-γand IFN-γfar away from CNNS,which can effectively prevent the quenching of fluorescence signal of Apt@IFN-γ.Use a fluorescence spectrophotometer to detect the fluorescence intensity in the reaction system,and explore CNNS/Apt@IFN-γfluorescent sensing platform the feasibility of detecting IFN-γ.（2）In the second chapter,based on a new two-dimensional nanomaterial,namely Mo S₂NS,and the nucleic acid aptamers,namely Apt@AFB1 that recognizes AFB1,we developed a fluorescent biosensor for detecting AFB1.The fluorescence signal of Apt@AFB1can be rapidly quenched by Mo S₂NS through Fluorescence Resonance Energy Transfer（FRET）.When Apt@AFB1 are present in the reaction solution,we add the target molecule AFB1.After the nucleic acid aptamers specifically bind with AFB1,the nucleic acid aptamers lose their single-chain structure and are far away from Mo S₂NS.Thus,the fluorescence signal of Apt@AFB1 can not be effectively quenched.Finally,fluorescence spectrophotometer was used to detect the fluorescence intensity in the reaction system to explore the feasibility of this method to detect AFB1.Results:（1）In the first chapter,the sensitive detection of IFN-γprotein can be achieved through the application of CNNS/Apt@IFN-γfluorescence sensing platform.Under optimized experimental conditions,In this method,the intensity of the fluorescent signal is positively correlated with the concentration of IFN-γ,of which the liner response range is 0.5-100ng/m L,showing a good linear response R²=0.9945,and the limit of detection is 0.303 ng/m L.This method can spcifically detect target IFN-γ.In addition,the fluorescence sensing platform can inspect the content of IFN-γin clinical serum samples without interference.The actual recovery rate of serum samples was 97.11%～106.96%.（2）In the second chapter,the sensitive detection of mycotoxin AFB1 can be achieved through the application of Mo S₂NS/Apt@AFB1 fluorescence sensing platform.Analysis after optimized conditions revealed a good linear response to the concentration level of AFB1 in the dynamic range of 0.2-25 ng/m L,R²=0.9964,and the limit of detection was 90 pg/m L.The recovery rate of the method applied to the actual sample serum and soybean milk were93.10%～107.23%and 95.15%～102.60%respectively,and it can be more accurately detected under the interference of other mycotoxins.Conclusion:In this study,CNNS/Apt@IFN-γand Mo S₂NS/Apt@AFB1sensing platforms were successfully constructed throung detecting the macromolecule IFN-γand the small molecule AFB1 as examples.They can serve as simple and fast biosensors for detecting IFN-γand AFB1,respectively.The good performance of CNNS,Mo S₂NS and aptamers with wide range of target were successfully verified,which is of great significance for the early diagnosis,pathogenesis and drug screening of pathogenic microorganism-related diseases.Meanwhile,this type of fluorescence sensing strategy can provide new ideas for research in disease related fields,and is a class of fluorescence sensing analysis methods that are worth promoting.