▎ 摘　　要

NOVELTY - Method for analyzing a single nucleotide polymorphism, involves preparing graphene oxide-iron(II,III) oxide (GO-Fe3O4) nanocomplexes, fixing GO-Fe3O4 nanocomplexes in the separation channel of polydimethylsiloxane (PDMS) microfluidic chip, preparing GO-Fe3O4 functionalized PDMS microfluidic chip separation channel, designing a single-stranded DNA labeled with methylene blue, hybridizing and mixing to prepare a mixed sample, using a high-voltage power supply as a fluid drive device, applying a separation voltage across the separation channel, adding the mixed sample, separating, detecting electrochemical signal, determining degree of separation of DNA/microRNA-21 and DNA/sm-microRNA-21, and separating and detecting single nucleotide polymorphism by GO-Fe3O4 functionalized PDMS microfluidic chip. USE - The method is useful for analyzing a single nucleotide polymorphism based on a magnetic functionalized microfluidic chip (claimed). ADVANTAGE - The method analyzes single nucleotide polymorphism simply and conveniently with reduced time consumption. DETAILED DESCRIPTION - Method for analyzing a single nucleotide polymorphism based on a magnetic functionalized microfluidic chip, involves (a) preparing graphene oxide-iron(II,III) oxide (GO-Fe3O4) nanocomplexes, fixing GO-Fe3O4 nanocomplexes in the separation channel of polydimethylsiloxane (PDMS) microfluidic chip under action of external magnet, and preparing GO-Fe3O4 functionalized PDMS microfluidic chip separation channel, (b) designing a single-stranded DNA labeled with methylene blue to be fully complementary to the microRNA-21 sequence and complementary to the microRNA-21 single-base mismatch sequence sm-microRNA-21, hybridizing the single-stranded DNA with microRNA-21 and sm-microRNA-21 to form a fully complementary stable DNA/microRNA-21 heteroduplex and a single base mismatched loose DNA/sm-microRNA-21 Heteroduplex, and then mixing DNA/microRNA-21 and DNA/sm-microRNA-21 to prepare a mixed sample, and (c) using a high-voltage power supply as a fluid drive device, applying a separation voltage of 1000 V across the separation channel of the PDMS microfluidic chip, rinsing the channel with the running buffer solution for 10 minutes, adding the mixed sample to the sample cell of the PDMS microfluidic chip, injecting and allowing the sample to flow through the PDMS microfluidic chip separation channel, after flowing through the GO-Fe3O4 functionalized PDMS microfluidic chip separation channel, separating DNA/microRNA-21 and DNA/sm-microRNA-21 in the mixed sample, combining with a three-electrode system, detecting electrochemical signal of methylene blue labeled on DNA, determining degree of separation of DNA/microRNA-21 and DNA/sm-microRNA-21 based on the retention time of the electrochemical signal of methylene blue, where the concentration of microRNA-21 and sm-microRNA-21 are determined with respect to the intensity of the electrochemical signal of methylene blue, and separating and detecting single nucleotide polymorphism by GO-Fe3O4 functionalized PDMS microfluidic chip.