Pd@PtCu Core–Shell Nanocrystal-Assisted Signal Amplification for Label-Free Electrochemical Immunoanalysis of the Human Fatty Acid Binding Protein Biomarker

Human fatty acid binding protein (H-FABP) is widely applied as a highly sensitive biomarker for early screening and diagnosis of acute myocardial infarction (AMI). Herein, mesoporous flower-like Pd@PtCu core–shell nanocrystals (MF-Pd@PtCu) were synthesized by a wet-chemical method, whose electrochemical active area, electrocatalytic property, and catalytic mechanism were rigorously investigated by a range of electrochemical techniques. The MF-Pd@PtCu derived label-free electrochemical immunosensor was built for analysis of H-FABP, which showed a wide linear range (0.0001–100 ng mL–1) and a low limit of detection (0.06 pg mL–1, S/N = 3), achieving analysis of H-FABP even in serum samples. This work provides some constructive guidelines for realizing immunoassays of other biomarkers, coupled with great prospects in medical application.