A Near-Infrared Fluorescence Chemosensor Based on Isothiocyanate-Aza-BODIPY for Cyanide Detection at the Parts per Billion Level: Applications in Buffer Media and Living Cell Imaging

Abstract

A near-infrared chemodosimeter based on an aza-BODIPY dye was designed and synthesized. The sensor contains isothiocyanate groups for cyanide ion sensing. The sensing function was illustrated via the fluorescence changes in near-infrared frequencies as well as chromogenic changes which could be easily visualized with a detection limit of 19 ppb. The sensor provides high selectivity to CN^- and discriminates other anions such as CH₃ COO^- , HPO₄^- , HSO₄^- , ClO₃^- , CO₃^2- , SO₄^2- , NO₃^- , Cl^- , F^- , Br^- , I^- , and phenylalanine (Phe) in 50 % PBS buffer/acetonitrile at physiological pH. The potential of the sensor for CN^- detection in both aqueous buffer solutions and living cells imaging was demonstrated.

Keywords: aza-BODIPY dyes; cyanide; near-infrared fluorescence; selectivity; sensors.