BODIPY-based sulfoxide: Synthesis, photophysical characterization and response to benzenethiols

Two BODIPY dyes bearing a sulfur containing function at the 3-position are reported. The 3-benzylthio compound shows spectroscopic features of the classical BODIPY platform, showing minor solvent dependent spectral shift, a relative small Stokes shift and a high fluorescence quantum yield. Oxidation of the sulfur atom to the sulfoxide leads to a large hypsochromic shift in absorption and emission. We also demonstrated that the sulfoxide derivative can be used as a ratiometric fluorescent chemodosimeter for highly toxic benzenethiols in aqueous media. In this dosimeter the sulfoxide is chemospecifically reduced by benzenethiols to obtain the original oxidation state of the sulfur atom, accompanied with a drastic ratiometric fluorescence response. Furthermore, the probe features excellent selectivity over other competing analytes, moderate signal response times and a good linearity range for quantification. All these features render the sensor suitable for detection of benzenethiols in environmental settings. (C) 2012 Elsevier Ltd. All rights reserved.