Confining signal probe in porous PdPtCoNi@Pt-skin nanopolyhedra to construct a sandwich-type electrochemical immmunosensor for ultrasensitive detection of creatine kinase-MB

Abstract Optimizing structures and compositions of nanomaterials holds great promise to develop highly sensitive electrochemical immunosensors in medical diagnosis and bioanalysis. Herein, we controllably synthesized porous PdPtCoNi@Pt-skin nanopolyhedra (PdPtCoNi@Pt-skin NP) by a one-pot green aqueous approach under the guidance of Pluronic F127 and successive oxidation etching with nitric acid (HNO3). Importantly, more thionine (Thi) was entrapped into porous PdPtCoNi@Pt-skin NP with enhanced loading and catalytic redox-ability. By virtue of the Thi-incorporated PdPtCoNi@Pt-skin NP and Au nanostars (NSs, behaved as electrode material), a novel sandwich-type electrochemical immmunosensor was constructed for ultrasensitive immunoassay of creatine kinase-MB (CK-MB). Under the optimal conditions, the as-developed immunosensor exhibited a wide linear range (0.001–2500 ng mL–1) and a very low detection limit (LOD = 0.62 pg mL–1, S/N = 3) for CK-MB detection, coupled with its further exploration in diluted human serum samples with acceptable results. The research would shed some valuable guidelines for clinical monitoring of other cardiac markers in medical diagnosis.