Highly potential-resolved anodic electrochemiluminescence multiplexing immunoassay with CuInS2@ZnS nanocrystals and [Ru(bpy)2(dcbpy)]2+ as emitters

Discriminating the electrochemiluminescence (ECL) of differed luminophores is crucial for ECL multiplexing. However, because of the limited potential window for ECL assay and the overlapped triggering-potential-range between different luminophores, the potential-resolved ECL multiplexing with good resolutions ( R s ) is still a great challenge. Herein, a single anodic ECL from two luminophores in the aqueous solution was discriminated completely (baseline separation, R s  ≥ 1.5) in a potential-resolved way with the water-soluble CuInS 2 @ZnS ( [email protected] ) nanocrystals (NCs) and [Ru(bpy) 2 (dcbpy)] 2+ as luminophores and N 2 H 4 as the co-reactant. N 2 H 4 could be electrochemically oxidized to reducing radicals and then reacted with the electrochemically oxidized [email protected] NCs and [Ru(bpy) 2 (dcbpy)] 2+ in sequence to produce co-reactant ECL. The potential-resolved ECL of [email protected] NCs/N 2 H 4 and [Ru(bpy) 2 (dcbpy)] 2+ /N 2 H 4 could be well defined and distinguished from each other upon potential scanning ( R s  = 2.60) and utilized for simultaneously determining human prostate specific antigen and carcinoma antigen 125 at the pathological cut-off concentration ( R s  = 1.56).