A　new　dual-amplification　strategy　of　electrochemical　signal　based　on　the　catalytic　recycling　of　the　product　was　developed　for　the　antigen-antibody　interaction　by　glucose　oxidase　(GOD)-　conjugated　gold-silver　hollow　microspheres　(AuAgHSs)　coupled　with　an　artificial　catalase,　Prussian　blue　nanoparticles　(PB),　on　a　graphene-based　immunosensing　platform.　The　first　signal　amplification　introduced　in　this　study　was　based　on　the　labeled　GOD　on　the　AuAgHSs　toward　the　catalytic　oxidation　of　glucose.　The　generated　H2O2　was　catalytically　reduced　by　the　immobilized　PB　on　the　graphene　nanosheets　with　the　second　amplification.　With　a　sandwich-type　immunoassay　format,　carcinoembryonic　antigen　(CEA)　was　monitored　as　a　model　analyte　by　using　the　synthesized　AuAgHSs　as　labels　in　pH　6.0　phosphate　buffer　containing　10　mM　glucose.　Under　optimal　conditions,　the　electrochemical　immunosensor　exhibited　a　wide　dynamic　range　of　0.005-50　ng　mL(-1)　with　a　low　detection　limit　(LOD)　of　1.0　pg　mL(-1)　CEA　(at　3　sigma).　Both　the　intra-　and　inter-assay　coefficients　of　variation　(CVs)　were　lower　than　10%.　The　specificity　and　stability　of　the　immunosensor　were　acceptable.　In　addition,　the　assay　was　evaluated　for　clinical　serum　specimens,　and　received　a　good　correlation　with　those　obtained　by　the　referenced　electrochemiluminescent　(ECL).　(C)　2011　Elsevier　B.V.　All　rights　reserved.