NiCoBP-doped　multi-walled　carbon　nanotube　(NiCoBP-MWCNT)　was　first　synthesized　by　using　induced　electroless-plating　method　and　functionalized　with　the　biomolecules　for　highly　efficient　electrochemical　immunoassay　of　prostate-specific　antigen　(PSA,　used　as　a　model　analyte).　We　discovered　that　the　as-synthesized　NiCoBP-MWCNT　had　the　ability　to　catalyze　the　glucose　oxidization　with　a　stable　and　well-defined　redox　peak.　The　catalytic　current　increased　with　the　increment　of　the　immobilized　NiCoBP-MWCNT　on　the　electrode.　Transmission　electron　microscope　(TEM)　and　energy　dispersive　X-ray　spectrometry　(EDX)　were　employed　to　characterize　the　as-prepared　NiCoBP-MWCNT.　Using　the　NiCoBP-MWCNT-conjugated　anti-PSA　antibody　as　the　signal-transduction　tag,　a　new　enzyme-free　electrochemical　immunoassay　protocol　could　be　designed　for　the　detection　of　target　PSA　on　the　capture　antibody-functionalized　immunosensing　interface.　Experimental　results　revealed　that　the　designed　immunoassay　system　could　exhibit　good　electrochemical　responses　toward　target　PSA,　and　allowed　the　detection　of　PSA　at　a　concentration　as　low　as　0.035　ng　mL　(1).　More　importantly,　the　NiCoBP-MWCNT-based　oxidase　mimetic　system　could　be　further　extended　for　the　monitoring　of　other　low-abundance　proteins　or　disease-related　biomarkers　by　tuning　the　target　antibody.　(C)　2014　Elsevier　B.V.　All　rights　reserved.