Application Of Sensors Based On Novel Nanomaterials And Nucleases In Biological Analysis

BackgroundThe detection of DNA specific sequences and proteins is crucial to the development of pathogen infections,genetic diseases,forensic analysis and modern life sciences.However,it is necessary to develop a new sensitive detection method for biological analysis because of the low content of the target and the large amount of impurities.Nanomaterials are widely used in biological analysis because of their unique optical properties and good biocompatibility.Nuclease is an enzyme that can cut off the phosphodiester bond of the nucleic acid chain and is often used as an important tool in biological analysis.The end protection of molecular chain DNA?TPSMLD?is a new method for protein detection,which converts the binding of small molecules and proteins into DNA recognition and opens up a new way for protein detection.In this study,a novel method of nucleic acid and protein detection with low background,good specificity and high sensitivity was developed through the DNA terminal protection technology and signal amplification technology of novel nanomaterials nuclease.Objectives?1?A fluorescence detection method based on cationic conjugated polymer and exoenzyme ? was constructed for protein detection and cell imaging,and detection of streptavidin and folic acid receptor and HeLa fluorescence imaging were realized.?2?A DNA double signal amplification detection method based on the fluorescence quenching performance of exonuclease ? and MOS₂ nanometer tablets was constructed to detect the human hemochromatosis gene.Methods?1?The high binding of SA and biotin prevents P1 from being digested by Exo ?,and the positively charged PFP approaches P1 through electrostatic interaction,so that FRET occurs from PFP to FAM,thus achieving the detection of the target protein;Due to the high affinity of P2's FR and folic acid receptor,PFP and P2 can be attached to the cell surface,and FRET occurs from PFP to P2,thus imaging HeLa cells.?2?The HP1 and hybridization target trigger exobiology ? of its degradation,release the fluorescent groups,HP1,T1 and target DNA,the release of target DNA can with another HP1 hybridization and start again,and T1 HP2 hybridization,exobiology ? from the 3'end of the H2gradually after hybridization catalytic removal of single nucleotide,release the fluorophore,eventually release the T1,a small number of target DNA in the circulation of cycle 1 and 2can produce a large number of fluorescent fragment so as to achieve the goal of signal amplification.Results?1?When SA was detected by fluorescence detection method based on cationic conjugate polymer and exoenzyme ?,the FRET ratio showed a significant linear relationship with the SA concentration within the concentration range of 2-200 ng ml^-1,and the detection limit was as low as 1.3 ng/ml.In 1%serum,there was still a good linear relationship between FRET ratio and SA concentration.When HeLa cells were mixed with P2,Exo ?,and PFP,mixed blue-green fluorescence occurred,and FRET occurred at FAM from PFP to P2.?2?Human hemochromatosis gene was detected by DNA double signal amplification based on the fluorescence quenching performance of exonuclease ? and MoS₂ nanometer tablets,with a linear range of 0.5-6.0 pM and a detection limit as low as0.28 pM.Conclusions?1?The protein detection method based on cationic conjugated polymer and Exo ? is used for 1%serum detection,FR detection and cell imaging.It provides a fluorescence detection method with higher sensitivity than the relevant fluorescence methods,and has potential applications in the biomedical field.?2?A high sensitivity and high selectivity DNA detection method was developed by using double signal amplification method and MoS₂ nanosheet.This method is very simple,simple and economical,and can be extended to a wide range of DNA detection fields through the rational design of corresponding probe sequences.