Abstract: | Present work demonstrates the fabrication of new and facile sandwich‐type electrochemical immunosensor based on palladium nanoparticles (PdNPs), polyaniline (PANI) and fullerene‐C60 nanocomposite film modified glassy carbon electrode (PdNP@PANI‐C60/GCE) for ultrasensitive detection of Prostate‐specific antigen (PSA) biomarker. PdNP@PANI‐C60 was electrochemically synthesized on GCE and used as an electroactive substrate. PdNP@PANI‐C60 was characterized by scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy (EDS), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Primary antibody anti‐PSA (Ab1) was covalently immobilized on PdNP@PANI‐C60/GCE using NHS/EDC linkers. In the presence of PSA antigen, horseradish peroxidase secondary antibody (HRP‐Ab2) was brought into the surface of the electrode, developing stable amplified signals of H2O2 reduction. Under the optimal conditions, a linear curve for determination of PSA at the proposed immunosensor was 1.6×10?4 ng.mL?1 to 38 ng.mL?1 with a limit of detection (LOD) of 1.95×10?5 ng.mL?1. The proposed immunosensor was successfully validated in serum and urine samples towards PSA detection with satisfactory and acceptable results. |