Thiocarbonyl quinacridone-based “turn on” fluorescent chemodosimeters for highly sensitive and selective detection of Hg(II)

Two new thiocarbonyl quinacridone compounds (TQA-H and TQA-TPA) were designed and synthesized, and their fluorescent behaviors toward various metal ions were investigated. The measurements of sensing behavior to various metal ions reveal that both of them are excellent “turn on” fluorescent chemosensors for mercury ion. Addition of Hg2+ to the chloroform solution of TQA-TPA gave the lowest detection limit at 4.7 nM. In addition, colorimetric changes of sensors interacted with Hg2+ are also successfully demonstrated. The recognition is attributed to Hg2+-induced conversion of thiocarbonyl quinacridones into their carbonyl analogues.