From pair to single: sole fluorophore for ratiometric sensing by dual-emitting quantum dots.

Intrinsic dual-emitting doped ZnS:Mn(2+) quantum dots are promising as sole fluorophore for ratiometric sensing. The ratiometric signals are reliably output by three kinds of modulation modes, namely, electron transfer, energy transfer, and chemical reaction, respectively. Compared with a conventional QD-based pair-fluorophore system, such a comprehensively ratiometric signal readout from a single fluorophore not only means a fundamental breakthrough but will substantially simplify the design and greatly promote the application of ratiometric sensing.