The Highly Selective and Sensitive Carbazole Derivative F^- Fluorescence-enhanced Probe

A carbazole derivative (HCTC) containing siloxy groups was synthesized using 4-hydroxycarbazole as the raw material. The structure was characterized with ¹H NMR and MS, and the F^- detection performance of the probe was studied. The results showed that HCTC could take advantage of the nucleophilicity of F^- to specifically attack the silicon-oxygen bond, showing the characteristics of a chemically reactive fluorescent probe towards F^-. Fluorescence test results showed that when F^- was added, a new fluorescence emission peak appeared in the probe solution at the wavelength of 433 nm, accompanied by a slight red shift, while the addition of other common anions could not cause fluorescence enhancement. In addition, the detection limit of F^- by HCTC was relatively low (0.21 μmol/L). Finally, the HCTC probe was prepared into a fluorescent test paper, which could detect F^- in an aqueous solution containing a small amount of acetonitrile. HCTC can be a fluorescence-enhanced probe with high selectivity and sensitivity.