Detection of Single Nucleotide Polymorphisms by Fluorescence Embedded Dye SYBR Green I Based on Graphene Oxide

Jiaoyun Xia; Tong Xu; Jing Qing; Lihua Wang; Junlong Tang

doi:10.3389/fchem.2021.631959

Detection of Single Nucleotide Polymorphisms by Fluorescence Embedded Dye SYBR Green I Based on Graphene Oxide

Front Chem. 2021 Mar 31:9:631959. doi: 10.3389/fchem.2021.631959. eCollection 2021.

Authors

Jiaoyun Xia¹, Tong Xu¹, Jing Qing¹, Lihua Wang², Junlong Tang³

Affiliations

¹ School of Chemistry and Food Engineering, Changsha University of Science and Technology, Changsha, China.
² Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, China.
³ School of Physics and Electronic Science, Changsha University of Science and Technology, Changsha, China.

Abstract

The detection of single nucleotide polymorphisms (SNPs) is of great significance in the early diagnosis of diseases and the rational use of drugs. Thus, a novel biosensor based on the quenching effect of fluorescence-embedded SYBR Green I (SG) dye and graphene oxide (GO) was introduced in this study. The probe DNA forms a double helix structure with perfectly complementary DNA (pcDNA) and 15 single-base mismatch DNA (smDNA) respectively. SG is highly intercalated with perfectly complementary dsDNA (pc-dsDNA) and exhibits strong fluorescence emission. Single-base mismatch dsDNA (SNPs) has a loose double-stranded structure and exhibits poor SG intercalation and low fluorescence sensing. At this time, the sensor still showed poor SNP discrimination. GO has a strong effect on single-stranded DNA (ssDNA), which can reduce the fluorescence response of probe DNA and eliminate background interference. And competitively combined with ssDNA in SNPs, quenching the fluorescence of SG/SNP, while the fluorescence value of pc-dsDNA was retained, increasing the signal-to-noise ratio. At this time, the sensor has obtained excellent SNP resolution. Different SNPs detect different intensities of fluorescence in the near-infrared region to evaluate the sensor's identification of SNPs. The experimental parameters such as incubation time, incubation temperature and salt concentration were optimized. Under optimal conditions, 1 nM DNA with 0-10 nM linear range and differentiate 5% SNP were achieved. The detection method does not require labeling, is low cost, simple in operation, exhibits high SNP discrimination and can be distinguished by SNP at room temperature.

Keywords: DNA sensor; SYBR Green I; fluorescence; graphene oxide; single nucleotide polymorphism.