A unique FRET approach toward detection of single-base mismatch DNA in BRCA1 gene

Early detection of mutation carriers in predisposing genes such as BRCA1 plays an important role in disease prevention. This work developed a quantum dots-based (QDs-based) fluorescence resonance energy transfer (FRET) technique for the detection of single-base mismatch DNA in BRCA1 gene. The FRET between QDs as the donor and silver nanocluster (AgNCs) as the acceptor was designed by the strong interaction between CdTe QDs with appropriate size and dsDNA through binding to its major groove. The dsDNA was formed by the hybridization of ssDNA labeled to AgNCs with target DNA, which introduced CdTe QDs into the major grooves to place the AgNCs in close proximity to the QDs. The complementary and single-base mismatch DNA led to obviously different FRET signals. The FRET signal linearly correlated to the concentration of single-base mismatch DNA in the range of 1.5 × 10^-10-1.0 × 10^-6 mol L^-1. The proposed method showed a detection limit of 80 pmol L^-1 and the sensitivity comparable to the previously reported assays, indicating promising potential for single nucleotide polymorphisms diagnosis in clinical application.