A　sensitive　and　feasible　multiplexed　immunoassay　protocol　for　simultaneous　electrochemical　determination　of　carcinoembryonic　antigen　(CEA)　and　alpha-fetoprotein　(AFP)　was　developed　using　multifunctionalized　graphene　nanotags　on　a　cyclodextrin-modified　immunosensor.　The　sensor　was　fabricated　via　the　guest-host　chemistry　between　the　immobilized　cyclodextrin　and　anti-CEA/anti-AFP　antibodies.　Two　nanotags　including　cyclodextrin-thionine-graphene　and　cyclodextrin-ferrocene-graphene　nanostructures　were　synthesized　based　on　a　wet　chemistry　method.　The　synthesized　nanotags　were　employed　for　the　labelling　of　horseradish　peroxidase　(HRP)-anti-AFP　and　HRP-anti-CEA　conjugates,　respectively.　With　a　sandwich-type　assay　format,　the　signal　was　monitored　through　the　labelling　of　HRP　toward　catalytic　reduction　of　H2O2　at　various　peak　potentials　in　the　presence　of　thionine　and　ferrocene,　respectively.　Under　optimal　conditions,　the　multiplexed　immunoassay　enabled　the　simultaneous　determination　of　CEA　and　AFP　with　wide　working　ranges　of　0.001-60ngmL-1　for　AFP　and　0.003-40ngmL-1　for　CEA.　The　detection　limits　were　0.5pgml-1　for　AFP　and　0.8pgml-1　for　CEA　(at　3sB).　No　obvious　nonspecific　adsorption　and　cross-talk　were　observed　during　a　series　of　analyses　to　detect　target　analytes.　Intra-　and　inter-assay　coefficients　of　variation　(CV)　were　below　9.5%.　Importantly,　the　methodology　was　also　evaluated　for　the　analysis　of　AFP　and　CEA　in　the　clinical　human　serum　specimens,　receiving　a　good　relationship　between　the　developed　immunoassay　and　a　commercialized　electrochemiluminescence　enzyme-linked　immunoassay.　Multitasker:　A　sensitive　and　feasible　multiplexed　immunoassay　protocol　for　simultaneous　electrochemical　determination　of　biomarkers　is　presented.　The　assay　uses　multifunctionalized　graphene　nanotags　on　a　cyclodextrin-modified　immunosensor.　©　2014　WILEY-VCH　Verlag　GmbH　&　Co.　KGaA,　Weinheim.