PET/d-PET (PdP) Pairing for the Design of Dual-Channel Probes.

Design principles of two-channel fluorescence probes are limited. Herein, we report a new principle, , PET/d-PET (PdP) pairing, for the rational design of two-channel probes. Two fluorophores are required in such a PdP-type probe. They mutually quench their fluorescence PET and d-PET. In the presence of an analyte-of-interest, such a PdP pair is converted into a FRET pair for signaling. The embodiment of such a principle is , by tethering a rhodamine fluorophore with an ROS-sensitive probe (). Fluorescence of both fluorophores in was quenched as expected. The addition of highly reactive oxidative species led to the recovery of the fluorescence properties of both. The simultaneous fluorescence enhancement in two channels is a viable way to avoid false-positive signals. The new PdP principle could potentially be applied to the development of probes for another range of substrates.