Prostate-specific　antigen　(PSA),　as　a　glycoprotein　enzyme　encoded　in　humans　by　the　KLK3　gene,　is　one　of　the　most　important　biomarkers　for　the　diagnosis　and　prognosis　of　prostate　cancer.　Herein,　a　new　electrochemical　immunosensor　for　sensitive　determination　of　PSA　was　designed　by　using　redox　and　catalysis　＇all-in-one＇　infinite　coordination　polymer　(PtNP@ICP)　as　signal　tag　on　the　polyamidoamine　dendrimers　modified　electrode　interface.　To　construct　such　＇all-in-one＇　PtNP@ICP　nanostructures,　the　coordination　polymerization　was　fully　carried　between　metal　ions　and　polydentate　bridging　ligands,　and　the　PtNP　was　encapsulated　into　the　ICP　in　the　process　of　polymerization.　The　prepared　PtNP@ICP　nanocatalyst　was　characterized　by　transmission　electron　microscope　(TEM),　energy　dispersive　X-ray　spectrometry　(EDX),　ultraviolet　and　visible　(UV-vis)　spectrophotometry　and　Fourier　transform　infrared　spectroscope　(FTIR).　And　the　synthesized　PtNP@ICP　was　utilized　as　signal　tag　for　the　label　of　PSA.　With　a　sandwich-type　immunoassay　format,　the　conjugated　signal　tag　on　the　transducer　increased　with　the　increasing　PSA　concentration　in　the　sample　thus　enhancing　the　signal　of　the　electrochemical　immunosensor　due　to　the　catalytic　reduction　toward　H2O2　of　the　enveloped　PtNP.　Under　optimal　conditions,　the　current　was　proportional　to　the　logarithm　of　PSA　concentration　ranging　from　0.001　to　60　ng/mL.　The　detection　limit　(LOD)　was　0.3　pg/mL　at　3s(B).　The　immunosensor　displayed　an　acceptable　reproducibility,　stability　and　selectivity.　In　addition,　the　methodology　was　evaluated　with　human　serum　specimens　receiving　good　correlation　with　results　from　commercialized　enzyme-linked　immunosorbent　assay　(ELISA)　method.　(C)　2014　Elsevier　B.V.　All　rights　reserved.