A copper(II) complex as selective turn-on fluorosensor for nitric oxide and its intracellular application

• Cu(II) complex of 4-(2-hydroxybenzylamino)-5-hydroxynaphthalene-2,7-disulfonic acid (FL1) was synthesized.
• NO induced fluorescence enhancement of the complex occurs by reduction of Cu(II) to Cu(I).
• The selective turn on fluorogenic nature of the complex was used to study the endogenously produced NO in living cells.

A highly water soluble copper(II) complex, 1 of a fluorophore ligand 4-(2-hydroxybenzylamino)-5-hydroxynaphthalene-2,7-disulfonic acid (FL1) was synthesized and characterized. In the complex, the fluorescence intensity of the ligand was found to quench due to the presence of paramagnetic Cu(II) center. In degassed methanol solution of complex 1, the Cu(II) center was found to undergo reduction in presence of nitric oxide. This resulted in the simultaneous formation of N-nitrosated ligand. In the process, the quenched fluorescence intensity of the ligand restored. The selective turn on fluorogenic nature of the complex 1 was used to study the endogenously produced NO in living cells.

A highly water soluble copper(II) complex of a fluorophore ligand FL1 was synthesized. The NO-induced fluorescence enhancement of [Cu(FL1)] occurs by the reduction of Cu(II) to Cu(I) with simultaneous formation of the N-nitrosated ligand. The selective turn on fluorogenic nature of the complex has been used to study the endogenously produced NO in live cells.Figure optionsDownload as PowerPoint slide