Detection Of ATP And MicroRNA Based On Enzymatic Recycling Amplification Reaction And Nanomaterials

Malignant tumor,which is called “cancer”,is one of the serious diseases that endanger our health.Nowadays,with the study of cancer becoming more and more deeply,the detection methods of cancer increasing more and more quickly.The detection of tumor markers is very important.Tumor markers are abnormal products of malignant tumor cells,or the host produces which is stimulated by the tumor.Detection of tumor markers has a large auxiliary function for cancer diagnosis.In order to detect tumor markers,biosensor as a kind of advanced detection methods has been widely used in biochemical analysis.This article constructed multiple DNA biosensors which are based on the principle of complementary base pairing,the catalytic performance of DNA enzymes and the special properties of nanomaterials to detect tumor markers of malignant tumor cells.High selectivity and high sensitivity detections of genes and biological molecules were realized.The main researches include the following several aspects:1?Detection of ATP based on the specific binding of ATP with ATP aptamer,the enzymatic recycling amplification reaction catalyzed by Klenow polymerase and Exo III and the special properties of polydopamine nanospheres.A polydopamine nanosphere biosensor was designed for the detection of ATP,and two enzymatic recycling amplification processes were included.ATP can bind with ATP aptamer,and make Reporter DNA strands free down.Then,more Reporter DNA strands were produced by the enzymatic recycling amplification reaction catalyzed by Klenow polymerase.Reporter DNA strands can hybridize with DNA strands which were adsorbed onto polydopamine nanospheres and modified with FAM,and make these strands of DNA leave from polydopamine nanospheres.The fluorescence of FAM was recovered.Through the enzymatic recycling amplification reaction catalyzed by Exo III,more fluorescence groups were separated from polydopamine nanospheres.Finally,with the fluorescence analysis of the reaction system,the purpose of high selectivity and high sensitivity detection of ATP was achieved.2?Visual detection of ATP based on the enzymatic recycling amplification reaction catalyzed by Klenow polymerase and the special properties of gold nanoparticles.ATP can bind with ATP aptamer,and make Linker DNA strands free down.Then,more Linker DNA strands were produced by the enzymatic recycling amplification reaction catalyzed by Klenow polymerase.Linker DNA strand as a bridge to connect gold nanoparticles which were modified with two different DNA strands through DNA hybridization,the gold nanoparticles were connected together.Coagulation of gold nanoparticles resulted in a color transition from red to purple.Visual inspection of ATP was reached.3?High sensitivity detection of microRNA-21 based on the enzymatic recycling amplification reaction catalyzed by Klenow polymerase and Nb.BsmI and molecular beacons.Two enzymatic recycling amplification processes were included.Micro RNA-21 can induce the enzymatic recycling amplification reaction catalyzed by Klenow polymerase.The special DNA strands which were produced can further hybridize with molecular beacons.The enzyme cutting site of Nb.BsmI was appeared.After that,the enzymatic recycling amplification reaction catalyzed by Nb.Bsm I was induced.Fluorophore and quencher of molecular beacon were separated.The fluorescence was recovered.Finally,through the fluorescence detection of the reaction system,the goal of high sensitivity detection of micro RNA-21 was attained.