A　new　electrochemical　immunoassay　protocol　for　sensitive　detection　of　alpha-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　3　sigma).　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.　(C)　2010　Elsevier　B.V.　All　rights　reserved.