Phenothiazine–aminothiourea–Hg(II) ensemble-based fluorescence turn-on toward iodide in aqueous media and imaging application in live cells

A phenothiazine–aminothiourea-based open chemosensor ( P1 ) has been designed and synthesized, which exhibits high selectivity toward Hg 2+ by forming a 1:1 complex. In its Hg 2+ ensemble, it is reported as a highly sensitive and selective probe for the detection of iodide based on the displacement approach in aqueous solution. The addition of iodide to a solution of phenothiazine–aminothiourea–Hg 2+ ensemble resulted in a rapid and remarkable fluorescence off–on (emission at 565   nm). The practical use of an ‘ensemble’ was demonstrated by its application to the detection of iodide in the living cells.