Tetraphenylethene-based platinum (II) complex with aggregation- induced electrochemiluminescence for the detection of glutathione

Abstract

Aggregation-induced electrochemiluminescence (AIECL) has been attracting great interests in ECL study, while it is still a big challenge to develop AIECL fluorophores with high emission efficiency and fair excitation potential. Herein, we develop a new ECL reagent platinum (II)-1,1,2,2-tetrakis(4-(pyridin-4-yl) phenyl) ethylene (Pt-TPPE) self-assembled via the coordination of pyridine group of TPPE and the metal cation of Pt (II). The resulting Pt-TPPE demonstrates excellent ECL emission properties in terms of high ECL emission efficiency and significant shift of ECL excitation potential from -1.6 V to -1.3 V. The corresponding ECL emission mechanism indicates that the formation of Pt-TPPE greatly limits the movement of TPPE ligand to reduce the non-radiated emission, and the catalytic decomposition of co-reactant K2S2O8 into SO4.− by Pt (II) cation is responsible for the shift of the excitation potential. The competitive coordination of thiol group with the Pt(II) cation effectively dissociate the Pt-TPPE complex, resulting in the quenching of its ECL emission, enabling the sensitive determination of thiol-carrying compound glutathione (GSH) with a low limit of detection (LOD = 0.298 μM) and wide linear range (1 μM-1 mM).