5,10,15,20-Tetraphenyl-21H,23H-porphine　cobalt　flat　stacking　on　the　reduced　graphene　oxide　with　platinum　nanoparticles　(PtNPs/CoTPP/rGO)　were　first　synthesized　and　functionalized　with　monoclonal　rabbit　anti-aflatoxin　B-1　antibody　(anti-AFB(1))　for　highly　efficient　electrochemical　immunoassay　of　aflatoxin　B-1　(AFB(1))　in　this　work.　Transmission　electron　microscopy　(TEM),　atomic　force　microscope　(AFM)　and　spectral　techniques　were　employed　to　characterize　the　PtNPs/CoTPP/rGO　hybrids.　Using　anti-AFB(1)-conjugated　PtNPs/CoTPP/rGO　as　the　signal-transduction　tag,　a　novel　non-enzymatic　electrochemical　immunosensing　system　was　designed　for　detection　of　target　AFB(1)　on　the　AFB(1)-bovine　serum　albumin-functionalized　sensing　interface.　Experimental　results　revealed　that　the　designed　immunoassay　could　exhibit　good　electrochemical　responses　for　target　analyte　and　allowed　the　detection　of　AFB(1)　at　a　concentration　as　low　as　5.0　pg　mL(-1)　(5.0　ppt).　Intra-　and　inter-assay　coefficients　of　variation　were　below　10%.　Importantly,　the　methodology　was　further　validated　for　analyzing　naturally　contaminated　or　spiked　blank　peanut　samples　with　consistent　results　obtained　by　AFB(1)　ELISA　kit,　thus　providing　a　promising　approach　for　quantitative　monitoring　of　organic　pollutants.