A highly efficient fluorescent probe based on tetrahydroxanthylium–coumarin for the detection of bisulfite in mitochondria. Issue 34 (15th August 2019) - Wu, Meng-Xiang
Abstract : A fluorescent probe based on tetrahydroxanthylium–coumarin was designed and synthesized for the detection of bisulfite in an aqueous solution and mitochondria. Abstract : The addition of bisulfite to an electron-withdrawing double bond has been reported for the design of a bisulfite probe; however, the selectivity of this reaction is usually influenced by an oxidation reaction with hypochlorite. Herein, a probe (probe1 ) with tetrahydroxanthylium and coumarin units was designed for the detection of bisulfite. The probe1 exhibited high selectivity, an obvious colour change from blue to yellow and a large turn-on signal (144-fold enhancement) with green emission towards bisulfite in an acetonitrile-phosphate buffered saline (1 : 9, v/v) solution. In addition, an excellent linear relationship between the fluorescence intensity at 514 nm and bisulfite concentration (0–2 equivalent) was obtained. Moreover, the response time of the probe1 towards bisulfite was within the order of several seconds, and the detection limit was calculated to be 22.8 nM. The mechanism of the detection reaction was proved by both the 1 H NMR analysis and time-dependent density functional theory (TDDFT) calculations. The results of the fluorescence co-localization studies demonstrate that the probe1 is a mitochondria-targeted fluorescent probe that can be used for the bioimaging of bisulfite in living HeLa cells.