Physical mechanism of concentration-dependent fluorescence resonance energy transfer

We experimentally report fluorescence resonance energy transfer (FRET), using a novel visualization method of excitation-emission mapping. Firstly, both the absorption and fluorescent spectra of donor and acceptor are measured, respectively, under different molecular concentrations for verifying that these two molecules are suitable for exploring FRET. And then, the excitation-emission mappings of FRET are investigated to reveal the internal regular pattern of FRET. Our theoretical calculations strongly support experimental results of FRET. Our experimental results provided a new visualization method to clearly understand the mechanism of FRET.