Measuring interactions and conformational changes of DNA molecules using electrochemiluminescence resonance energy transfer in the conjugates consisting of luminol, DNA and quantum dot

A method based on electrochemiluminescence resonance energy transfer (ECRET) between luminol as the donor and CdSe/ZnS quantum dot (QD) for evaluation of the interactions between DNAs and measurement of the conformational changes of DNAs was developed. When a positive potential was applied to the conjugates consisting luminol, DNA and QD, ECRET between luminol molecules and QDs could be detected in 0.2mol/L Na2CO3–NaHCO3 buffer (pH 10) containing 1.0×10−2mol/L H2O2. In this case, luminol molecules emitted a light with a maximum emission (λm) of 460nm or transferred energy to proximal ground-state QDs. The excited state QDs relaxed to their ground state by emitting a light with a λm of 655nm. The ECRET between luminol and QD was used to evaluate interactions between DNAs and to measure conformational changes of DNAs.