A Molecular Recognition Mode With Dynamic Fingerprint Signal For Detecting Sandwich Structural Molecule

Typical biomolecules(such as nucleic acids,peptides,proteins,etc.)play an important roles in various biochemical reactions and cellular activities such as genetics,epigenetics,gene expression,etc.However,these biomolecules are in actual detection systems(eg.the concentration in the blood)is usually low.In recent years,with the development of fluorescence microscopy technology,single molecule detection as a new detection method with higher sensitivity provides a new idea for the detection of biomolecules.In order to further improve the stability and specificity of the single molecule detection method and avoid the cumbersome operation steps required to deduct the background in the detection,the probe system construction with high recognition fingerprint type signal is an effective solution.In this study,a dynamic TWJ-type detection probe system based on nucleic acid nanostructures was designed.This dynamic TWJ-type detection probe consists essentially of four single-stranded oligonucleotides,including capture probes,fluorescently labeled signal probes,and two recognition probes that bind to the target to be detected.The assembly of the recognition probe with the signal receiving arm,and subsequent dynamic hybridization with the fluorescent probe,is triggered if and only if two recognition probes are bound to the target.High specificity has been demonstrated in suitable hybridization kinetics and ionic strength.When the two recognition probes are unable to bind stably,that is,in the absence of the detected target,the system does not exhibit a specific fluorescence signal map.In this study,the constructed detection probe system was used for the matching of "sandwich type" molecular recognition mode,and the oligonucleotide sequence detection and the application practice of ATP and thrombin using nucleic acid aptamers were respectively carried out.Experiments show that the TWJ-type dynamic hybridization detection probe constructed in this study has good specificity in actual detection,and provides a new tool for detection of biomolecule terminal detection and interaction.