3,5-Diformyl-borondipyrromethene for selective detection of cyanide anion

Cyanide is one of the most toxic inorganic anions, it is very harmful to human health but extremely useful in industrial activities. Herein, we used our recently reported boradiazaindacene (BODIPY) dye, 3,5-diformyl-borondipyrromethene (BODIPY 1) as an exclusive chemodosimetric and colorimetric sensor for CN− ion. Cyanide ion attacks the carbonyl groups of 1via a nucleophilic addition reaction and converts to cyanohydrin which is reflected in the clear colour change as well as by the absorption, emission and electrochemical properties. Thus BODIPY 1 can be used as a colorimetric and chemodosimetric sensor for CN− ion. Furthermore, to show that the position of the formyl group on BODIPY plays an important role in the ability of BODIPY dye to act as a chemodosimetric sensor for CN− ion, we synthesized another formyl group containing BODIPY dye, 3, in which the formyl group is present at the para-position of the meso-phenyl group. 1H NMR studies confirmed the formation of the cyanohydrin form of BODIPY dye 3 on addition of CN− ion but dye 3 cannot be used as a chemodosimetric sensor for CN− ion, as verified by absorption and fluorescence studies. The detection of cyanide with BODIPY dye 1 for biological application was also performed in MDA-MB-231 cells.