A　new　electrochemical　immunoassay　protocol　for　sensitive　detection　of　α-fetoprotein　(AFP,　as　a　model)　is　designed　using　carbon　nanoparticles　(CNPs)-functionalized　biomimetic　interface　as　immunosensing　probe　and　irregular-shaped　gold　nanoparticles　(ISNGs)-labeled　horseradish　peroxidase-.　anti-AFP　conjugates　(HRP-.　anti-AFP-ISNG)　as　trace　label.　The　low-toxic　and　high-conductive　CNPs　provided　a　high　capacity　nanoparticulate　immobilization　surface　and　a　facile　pathway　for　electron　transfer.　In　comparison　with　conventional　label　methods,　i.e.　spherical　gold　nanoparticles-labeled　HRP-.　anti-AFP　and　HRP-labeled　anti-AFP,　the　electrochemical　immunosensor　using　HRP-.　anti-AFP-ISNGs　as　trace　labels　exhibited　high　bioelectrocatalytic　response　toward　enzyme　substrate　and　a　wide　dynamic　range　from　0.02　to　4.0.　ng/mL　with　a　low　detection　limit　of　10.　pg/mL　toward　AFP　(at　3σ).　The　developed　immunoassay　method　showed　good　selectivity　and　acceptable　reproducibility.　Clinical　serum　samples　with　various　AFP　concentrations　were　evaluated　by　using　the　electrochemical　immunosensor　and　the　referenced　enzyme-linked　immunosorbent　assay　(ELISA),　respectively,　and　received　in　good　accordance　with　results　obtained　from　these　two　methods.　©　2010　Elsevier　B.V.