Facile and highly selective sensing of hypochlorous acid in aqueous solution and living cells by using as-prepared WSe2 quantum dots

The monitoring of biological hypochlorous acid (HClO) in living cells is vital in clarifying its physiological functions. Generally, HClO fluorescent probes that can be used for intracellular detection are small organic molecules that require complex synthesis steps. Herein, the as-prepared WSe 2 quantum dots (QDs) without any further modification was verified to be a HClO fluorescent probe due to the unique chemical property of selenium. Compared with molecular probes, WSe 2 QDs displayed improved performance in HClO detection, such as the low limit of detection (1.1 nM), high selectivity, fast response, good aqueous solubility, friendly operation, excellent photostability, and pH-independent response. Furthermore, the most outstanding advantage of as-prepared WSe 2 QDs was their ready availability with up to the gram-large scale. WSe 2 QDs were successfully used for the detection of exogenous and endogenous HClO in living cells. Meanwhile, this probe was applied to discriminate normal cells and cancerous cells on the basal of their different HClO levels. The sensing mechanism of WSe 2 QDs to HClO was further carefully demonstrated and proposed to be HClO induced the oxidation and degradation of WSe 2 QDs into non-fluorescent products. We anticipate that the as-prepared WSe 2 QDs should have broad applications in chemical analysis and revealing the physiological function of HClO in vivo .