Highly Selective Colorimetric Chemosensor for Co2+

A new highly selective colorimetric chemosensor for Co2+ was developed based on coumarin-conjugated thiocarbanohydrazone. The ligand senses Co2+ in solution by, changing its color from light yellow to deep pink. The sensor has been used in the development of practically viable colorimetric kits and as a staining agent for Co2+ in microorganisms.