Fluorescence Resonance Energy Transfer Between Quantumn Dots

The fluorescent resonance energy transfer(FRET) between two kinds of quantum dots(QDs) with different surface-charge was researched. Green-emission QDs was modified with amphiphilic surfactants (CTMAB) and red-emission QDs was modified with thiolglycolic acid (TGA) separately. The experiments proved that both CTMAB and TGA both could well turn the oil-soluble QDs into water-soluble ones, as well as opposite electric charges on the surface. Then the water-soluble QDs were characterized by agarose gel electrophoresis, fluorescence image and quantum yield. Taking advantage of the interaction between the opposite charges, fluorescent resonance energy transfer(FRET) was detected between two kinds of QDs in phosphate buffer solution(pH 7.5) with an excitation wavelength of 400 nm, and the FRET efficiencies were satisfied (quenching efficiency was 0.54 and enhance efficiency was 0.27).