Development Of New Methods For The Rapid Detection Of MicroRNA Based On The Nucleic Acid Lateral Flow

With the accelerated pace of life and changes in diet,cancer population increased,thus the early diagnosis and postoperative monitoring is particularly important.The expression level of microRNA is closely linked with the cancer occurrence.In addition,microRNA can be ingested into the human body through daily food intake,so as to regulate the expression of human target gene,and thus affect the body's physiological function.And there are many kinds of microRNAs,therefore designing rapid,simple,high sensitive and multiplex detection methods for microRNA is significant in the food nutrition and safety,medical field and other related fields.This article introduces the following two detection methods:1.Multiple detection of microRNA based on the lateral flow nucleic acid test stripsThis method utilizes three groups of Au-SH probe-T probe sandwich structure to achieve the microRNA triple detection.SH probe was first immobilized on the surface of gold nanoparticles,and T probe was immobilized on the NC membrane.Then target microRNA hybridized with SH probe and T probe partially to form a sandwich structure which captures and retains gold nanoparticles on the NC membrane.We observed visual band by the accumulating of gold nanoparticles on the test line.The detection limits of designed single detection strips for microRNA-21,microRNA-155 and microRNA-210 were 1 nM,5 nM and 5 nM respectively.The designed multiple detection strips realized three target detection well with no cross-reaction.2.Surface enhanced Raman spectra based on the lateral chromatography technology for microRNA dual detectionThis method based on the formation of Au@Ag-SH probe-T probe sandwich.We first modified Raman signal molecule on the Au@Ag surface before immobilizing detection probe.When Au@Ag modified with Raman signal molecule was retained on the test line,the concentration of target can be estimated by naked eyes according to the intensity of test line and the signal can be observed on the concentration range that cannot be distinguished by the naked eyes through the Raman spectroscopy,thereby improving the detection sensitivity.The Raman detection limits for microRNA-21 and microRNA-155 were 0.5 nM and 1 nM respectively.In addition,microRNA-21 and microRNA-155 were detected simultaneously on one test line according to the different Rho-6G and 4-ATP Raman peaks.