Novel graphene/Au-CdS:Eu composite-based electrochemiluminescence immunosensor for cancer biomarker detection by coupling resonance energy transfer and enzyme catalytic reaction

Recent studies show that ECL resonance energy transfer (ECL-RET) coupled with H 2 O 2 -related enzymatic reactions is an efficient strategy for designing excellent ECL biosensors with high sensitivity. Here we find that a ternary composite named graphene/Au-CdS:Eu QDs demonstrated ECL-RET effect with Au nanorods (Au NRs) and horseradish peroxidase (HRP) on the Au NRs could catalyze hydrogen peroxide reduction in the presence of hydroquinone (HQ). Therefore, we developed an efficient dual-quenching ECL immunosensor based on the novel ternary composite with high ECL intensity coupled with H 2 O 2 -related enzymatic reactions and ECL-RET strategy from Au NRs. This ultrasensitive ECL sensing strategy combined the advantages of the excellent ECL sensing properties of graphene/Au-CdS:Eu QDs, and dual-quenching effect and achieve sensitive detection of alpha fetoprotein (AFP).