A BODIPY-based dye with red fluorescence in solid state and used as a fluorescent and colorimetric probe for highly selective detection of cyanide

Abstract

Borondipyrromethene (BODIPY) dyes with strong red solid-state photoluminescence are highly desirable for their applications. In this work, a novel BODIPY dye (1) containing para-bromophenyl at meso position as a molecular separator and dicyanovinyl group on the 2 position as asymmetrical moiety was prepared. The emission peaks of 1 in THF and powder are 548nm and 640nm with emission quantum yield of 55.4% and 4.7%, respectively. Moreover, 1 can be used as a fluorescent and colorimetric probe for the detection of cyanide, which is attributable to the addition of CN− to the electron-deficient dicyanovinyl group of 1. It shows that the color changes from yellow to purple when CN− is added to 1 in THF/H2O (10/1, v/v). The maximum emission intensity at 548nm is quenched 96%, which constitutes the fluorescence signature for cyanide detection. Furthermore, probe 1 achieves rapid detection of cyanide anion within 1min. However, other anions do not induce any significant change of absorption/emission spectrum of 1. Notably, the test strips and silica based – 1 can successfully detect CN−.