4,5-Dimethylthio-4‘-[2-(9-anthryloxy)ethylthio]tetrathiafulvalene, a Highly Selective and Sensitive Chemiluminescence Probe for Singlet Oxygen

Abstract

4,5-Dimethylthio-4‘-[2-(9-anthryloxy)ethylthio]tetrathiafulvalene has been designed and synthesized as a highly selective and sensitive chemiluminescence (CL) probe for singlet oxygen (¹O₂). The design strategy for the probe is directed by the idea of photoinduced electron-transfer process and carried out through the incorporation of electron-rich tetrathiafulvalene unit into a reactive luminophore of anthracene specific for ¹O₂. Upon reaction with reactive oxygen species (ROS), such as hydrogen peroxide, hypochlorite, superoxide, hydroxyl radical, or ¹O₂, the probe exhibits both strong CL response to and high selectivity for ¹O₂ only, rather than the other ROS. This remarkable CL property permits ¹O₂ to be distinguished easily from the other ROS and makes the probe possible to be used widely for ¹O₂ detection in many chemical and biological systems and even in light water (H₂O) environments. This applicability has been demonstrated by monitoring the ¹O₂ generation in a metal-catalyzed decomposition system of tert-butyl hydroperoxide. Moreover, the CL reaction mechanism of the present system is also discussed, clearly confirming that the introduction of electron-rich tetrathiafulvalene into the 9-position of anthracene can greatly activate its reactivity toward ¹O₂.