A highly selective phosphorescent chemodosimeter for cysteine and homocysteine based on platinum(II) complexes

A platinum(II) complex Pt(phen)CCC6H4CHO has been demonstrated as a highly selective phosphorescent chemodosimeter for cysteine and homocysteine. Upon addition of homocysteine or cysteine to its acetonitrile–water solution, an evident luminescent color variation from green to orange was observed. This red-shift of phosphorescence emission could be attributed to formation of a thiazinane through a selective reaction of aldehyde group of Pt(phen)CCC6H4CHO with cysteine/homocysteine, which was confirmed by 1H NMR investigation and density functional theory (DFT) calculations. The further selectivity investigation indicates that it displays high selectivity for homocysteine and cysteine, and therefore can be utilized as cysteine/homocysteine phosphorescent chemodosimeter.

Graphical abstractThe original solution of complex Pt(phen)CCC6H4CHO (1) in acetonitrile–water (40 μM, 4:1 v/v) showed a intensive phosphorescent emission centered at 510 nm. Upon addition of homocysteine or cysteine to this acetonitrile–water solution, an evident luminescent color variation from green to orange was observed.Figure optionsDownload full-size imageDownload as PowerPoint slide