Here　we　designed　a　new　electrochemical　immunoassay　protocol　for　determination　of　carcinoembryonic　antigen　(CEA)　using　nanoplatinum-enclosed　gold　nanocores　(Pt@Au)　as　catalytically　promoted　nanolabels　on　the　carbon　nanospheres　and　graphene-modified　immunosensor.　The　Pt@Au　nanolabels　were　synthesized　and　functionalized　with　monoclonal　anti-CEA　antibodies　and　glucose　oxidase　(GOx).　Using　the　functional　Pt@Au　nanolabels　as　molecular　tags,　the　assay　was　implemented　relative　to　glucose-hydroquinone　system　with　a　sandwich-type　immunoassay.　Initially,　the　added　glucose　was　oxidized　to　gluconolactone　and　H2O2　by　the　labeled　GOx,　and　then　the　generated　H2O2　was　reduced　with　the　help　of　platinum　nanoparticles,　leading　to　the　production　of　oxygen.　The　self-produced　oxygen　could　promote　the　re-oxidation　of　the　glucose,　thus　resulting　in　the　dual　amplification　of　the　electrochemical　signal.　Several　nanolabels,　such　as　multiarmed　star-like　platinum　nanowires,　hollow　platinum　nanospheres　and　Pt@Au　nanostructures,　were　investigated　for　CEA　detection　and　improved　analytical　features　were　obtained　with　the　Pt@Au　nanostructures.　Under　optimal　conditions,　the　Pt@Au-based　immunoassay　displayed　a　wide　working　range　from　0.001　to　120　ng　mL(-1)　with　a　low　detection　limit　of　0.5　pg　mL(-1)　CEA　at　3.s(B).　Intra-　and　inter-assay　coefficients　of　variation　were　＜10.9%.　The　system　was　evaluated　with　10　clinical　serum　samples,　receiving　good　accordance　with　results　from　enzyme-linked　immunosorbent　assay　method.　(c)　2012　Elsevier　B.V.　All　rights　reserved.