Electrochemiluminescence resonance energy transfer between quantum dots (QDs) as the donor and Cy5 dye molecules as the acceptor in QD-Cy5 conjugates with biomolecules as the linker

Electrochemiluminescence resonance energy transfer (ECRET) between CdSe/Zns quantum dots (QDs) as the donor and cyanine dye (Cy5) molecules as the acceptor in QD-Cy5 conjugates with DNA or protein as the linker was reported. When a negative potential was applied, the excited-state CdSe/ZnS* was produced in 0.1 mol/L phosphate buffer (pH 7.4) containing 0.1 mol/L K2S2O8 and 0.1 mol/L KNO3 (PB-K2S2O8). The CdSe/ZnS* went back to the ground-state CdSe/ZnS to emit light at 590 nm or to transfer energy to proximal ground-state Cy5 molecules. The resultant excited-state Cy5 molecules relaxed to their ground state by emitting a light at 675 nm. The ECRET between QDs and Cy5 was used to evaluate interactions between DNAs and to measure conformational changes of DNAs and proteins.

Graphical abstractElectrochemiluminescence resonance energy transfer between quantum dots as the donor and Cy5 dye molecules as the acceptor in QD-Cy5 conjugates with DNA or protein as the linker.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Electrochemiluminescence (ECL) spectra of CdSe/ZnS quantum dots are measured. ► ECL resonance energy transfer (ECRET) between quantum dot and Cy5 dye is studied. ► The ECRET system is used to evaluate interactions between DNAs. ► The ECRET system is used to measure conformational changes of DNA or protein. ► The ECRET system is used to measure distances between groups in biomolecules.