Radical Pair-Driven Luminescence of Quantum Dots for Specific Detection of Peroxynitrite in Living Cells

There is currently great interest in developing chemiluminescence (CL) probes that can selectively detect peroxynitrite (ONOO(-)) in living cells. In comparison with other reactive oxygen species (ROS), ONOO(-) can spontaneously decompose into a series of radicals. Notably, the interaction of quantum dots (QDs) with oxidizing/reducing ROS radicals can generate a strong CL emission by electron-transfer annihilation. Herein, we report a novel CL probe that affords the ability to distinguish ONOO(-) from other ROS in living cells. ONOO(-) can activate luminescence of QDs in the absence of excitation source, effectively avoiding background noise and scattering of light from biological matrixes produced by in situ excitation; however, there is no response to other ROS including (1)O2, H2O2, (•)OH, O2(•-), and ClO(-). The outstanding selectivity of the present CL probe leads us to detect the exogenous release of ONOO(-) from 3-morpholinosydnonimine (SIN-1) in living cells. These results suggest that this present probe-based CL provides a promising platform for highly selective and sensitive detection of ONOO(-) in biological systems.