Application Of DNA Nanostructures In The Detection Of Cancer-related Biomarkers

DNA nanostructures with high programmability,spatial addressability,and biocompatibility have greatly developed in the field of biosensing.At present,there are a variety of DNA biosensors based on different mechanisms,such as electrochemical DNA biosensors,optical DNA biosensors,etc.At the same time,DNA nanostructures performs large amounts of advantages such as excellent cellular permeability,high digestion-resistant ability,so that the target can still be detected in cell environment.The detection of cancer-related biomarkers has become a necessary means for biomedical research and clinical diagnosis.In normal cells,the content of cancerrelated biomarkers is extremely low,while in cancer cells,cancer-related biomarkers are expressed in large amounts.At present,in order to achieve accurate diagnosis of cancers in clinical practice,it is necessary to detect multiple cancer-related biomarkers at the same time.The traditional detection methods of cancer-related biomarkers mainly include PCR,serum examination and gene sequencing.However,these methods have the disadvantages of complicated operation and time-consuming,which reduce the detection efficiency and timeliness.In order to solve the above problems,a biosensor based on DNA tetrahedron is designed in this paper,which realizes the rapid and high efficiency detection of multiple cancer-related biomarkers(miRNA-21,pi RNA-36026).The content of this paper mainly has the following two aspects:(1)Design,synthesis and characterization of DNA tetrahedral sensors.The DNA tetrahedron sensor consists of DNA tetrahedron,miRNA-21 fluorescent probe and pi RNA-36026 fluorescent probe.When the target is present,the fluorescent probe and the target undergo a strand displacement reaction,which activates the fluorescent group it carries.Subsequently,we characterized the assembly,synthesis efficiency and stability of the DNA tetrahedral sensor(2)Detection of miRNA-21 and pi RNA-36026 by DNA tetrahedral sensor.In this section,the detection performance of the DNA tetrahedral sensor is explored in vitro and vivo,respectively.The detection sensitivity of the DNA tetrahedral sensor for miRNA-21 and pi RNA-36026 is about 10 n M.Then,we have successfully achieved the simultaneous detection of miRNA-21 and pi RNA-36026 in human breast cancer cells(MCF-7)through the DNA tetrahedral sensor.In summary,this paper has designed a rapid and efficient detection method for a variety of cancer markers,and demonstrated the excellent performance and development potential of the DNA biosensor.