Mutant DNA Detection on Graphene Oxide with SYBR Green I

Graphene oxide (GO) has a large surface-to-volume ratio and contains hydrophobic hexagonal rings that can interact with biomolecules. Single-stranded DNA (ssDNA) adsorbs more strongly to the surface of GO than double stranded DNA (dsDNA) via hydrophobic interaction between nucleobases of DNA and the hydrophobic surface of GO. This study was designed to detect samples containing various mismatched DNAs under different pH and salt conditions by sequential use of GO and SYBR Green I. Our results demonstrated that a GO-based fluorescence assay showed little difference in fluorescence intensity between perfectly matched DNA (pmDNA) and mutant DNAs. However, an SYBR Green I-assisted assay elicited large difference in fluorescence intensity between the pmDNA and mismatched DNAs. This enhances the detection sensitivity and efficiency between pmDNA and mutant DNA.