Turning on a high-rate-capability fluorescence resonance energy transfer in quantum dots-molecule system via high pressure

Turning on Fluorescence Resonance Energy Transfer (FRET) based on Quantum dot (QD)-molecule system plays crucial roles in developing photovoltaic solar cells, optical biosensing schemes and light-emitting devices. The present achievement of turn-on FRET is restricted to the approach of only controlling the spectral overlap, which need an efficient strategy to further accelerate the FRET process. Here, a new approach to turn on and facilitate the FRET process simultaneously in the CdSe/ZnS QD-Rhodamine640 system using in situ high-pressure technology is introduced. On the basis of pressure-tunable fluorescence spectrum of QD, the use of high pressure yields a spectral overlap from none to appreciable, thus “turning on” the FRET process. Simultaneously, the pressure significantly reduces the donor-acceptor distance and increases the number of adsorbed acceptor, thus ensuring the FRET process highly efficient and very rapid. The FRET rate at 3.6GPa can reach up to 5ps-1, which is a new record for spherical QDs system at present. This approach provided a new strategy for turning on and facilitating the FRET process, which is of significance for the development of potential QD-molecule-based FRET applications.