An origami electrochemiluminescence immunosensor based on gold/graphene for specific, sensitive point-of-care testing of carcinoembryonic antigen

In this work, an electroluminescence (ECL) immunosensor was introduced into a folding cellulose fiber paper based on gold/graphene modified screen-printed working electrode (SPWE) to develop an ECL microfluidic origami immunodevice. Graphene was used to modify the working electrode for its fast electron transportation, excellent mechanical stiffness and good biocompatibility. A dense gold layer was formed for the first time through the growth of gold nanoparticles on the graphene layer, to further enhance the sensitivity, stability and effective surface area of the SPWE. On this as-prepared SPWE, phenyleneethynylene derivative modified nanotubular mesoporous Pt–Ag alloy nanoparticles were used as signal amplifier for the highly sensitive determination of carcinoembryonic antigen in human serum sample in the linear range from 0.001 to 100 ng mL−1 with a low detection limit of 0.3 pg mL−1. The specificity, reproducibility, and stability of this microfluidic origami ECL immunodevice (μ-OECLID) were investigated in this work. This novel μ-OECLID would provide a new platform for low cost, sensitive, specific, multiplex assay and point-of-care diagnosis in public health, environmental monitoring, and the developing world.