Studies, Based On The The Graphene Oxide Quencher Fluorescent Detection Of Single Base Variation New Method

As the third generation of genetic markers system, single nucleotide polymorphisms (SNPs) refers to the genome sequence for single nucleotide (A, T, C or G) mutation and produces sequences of DNA polymorphisms. In the human chromosome, SNP are widely distributed and relatively stable. SNP detection is important in biological and clinical studies because SNPs are associated with diseases, anthropometric characteristics, phenotypic variations, and gene functions. A number of methods have been developed for detecting single-base mismatches. These methods include gel electrophoresis, mass spectrometry, oligonucleotide array, colorimetric sensing, surface plasmon resonance (SPR), fluorescence, and electrochemical sensing.Fluorescence analysis is a highly sensitive real-time detection method, which has been widely used in molecular recognition and biology research fields. Graphene oxide (GO) is a superquencher of the fluorescence of various dyes through the long-range energy transfer. Accordingly, we proposed a florescence sensing system for the recognition of mismatch based on GO.This paper includes two parts:the first part is reviewed, and the second part is the research report.The first chapter is part of the review. Mainly introduces the single nucleotide polymorphisms (SNPs) definition and detection method, Graphene and Graphene oxide of nature and the research progress. Finally, the purpose and content of this paper wer introduced.The second part is the research report. The first part of it is that a novel fluorescence method to detect SNPs method based on oxidation graphite surfaces platform. GO binds and quenches dye-labeled ssDNA probe through the π-stacking interaction between DNA bases and GO; meanwhile, hybridization of an ssDNA probe with complementary DNA releases dye-tagged ssDNA from GO and recovers the fluorescence. When the single-base mismatch target exists, part of fluorescence is recovered. In the above conditions, when certain concentration ATMND were added, small molecules selectively recognize mismatched dsDNA on the Watson-Crick face of the exposed bases and stabilize the duplex with a high base selectivity, meanwhile, making dye fluorescence further recover, and can achieve even more than the fluorescence intensity of adding fully complementary target DNA.The second part of the research report, a new method for distinguishing a C-C mismatch-containing dsDNA based on molecular beacon and ATMND. MBs have attracted much attention because of their stability, unique functionality, and molecular specificity. When a MB hybridizes with its complementary DNA, it undergoes a spontaneous conformational reorganization with the opening of the stem, leading to fluorescent restoration, when a MB hybridizes with including single base mismatch ssDNA, fluorescence also can have certain recover, however, when certain concentration ATMND were added in the above conditions, ATMND selectively recognize a C-C mismatch-containing dsDNA through the hydrogen bonding interaction. Due to enhance the stability of the double helix structure, it makes system fluorescence further strengthened, and achieves even more than the fluorescence intensity of adding fully complementary target ssDNA. Therefore, C-C mismatch can be detected.