N‐Aryl‐DABCO Salts as an Unprecedented Sensing Platform for the Detection of Thiols and Selenols

Abstract

AbstractQuaternary N‐aryl‐DABCO salts were introduced for the first time as a highly selective sensing platform for thiols and selenols. By employing this platform, a highly sensitive coumarin based “off‐on” fluorescent probe was designed and synthesized. The probe possesses a good solubility in water, low background fluorescence, and, most importantly, demonstrates high selectivity to aryl thiols and selenols over their aliphatic counterparts and other common nucleophiles. A dramatic increase in fluorescence intensity is achieved through the selective cleavage of the quaternized DABCO‐ring, yielding a piperazine derivatives with a high fluorescence quantum yield (~72 %). Moreover, stability of the probe to the most used reducing agents DTT and TCEP was demonstrated. The limits of detection for p‐thiocresol and phenyl selenide were evaluated to be 22 nM and 6 nM, respectively.