Electrochemical PSA Detection Performance of an Innovative Immunosensor

Prostate-specific antigen (PSA) is a protein produced by the prostate gland and is a critical biomarker for the early detection and monitoring of prostate cancer. Current methods in the detection of PSA include enzyme-linked immunosorbent assay (ELISA), chemiluminescent immunoassays (CLIA), and radioimmunoassay (RIA). They are expensive and time-consuming processes, even though they are considered the gold standard. On the other hand, biosensing technology is an emerging alternative method for the detection of PSA. Electrochemical immunosensor systems are widely used for detecting a variety of antigens with high selectivity and specificity. In this study, to prepare an immunosensor for PSA detection, a thiophene appended cobalt(II) phthalocyanine (CoPc), its polymer (Poly-Pc), and CuCoFe₂O₄@MoS₂–NH₂ were synthesized. Then, anti-PSA antibodies were immobilized on the CuCoFe₂O₄@MoS₂–NH₂-based Poly-Pc composite using glutaraldehyde as a cross-linker, and the immunosensor was prepared. Differential pulse voltammetry (DPV) employed to monitor the measurements showed that the proposed immunosensor system exhibited excellent analytical performance, with a wide linear detection range (0.01–1000 ng/mL) and a low detection limit of 6.3 pg/mL. The proposed immunosensor system offered high selectivity, reproducibility, and stability, even in complex biological samples such as synthetic serum, which was compared to a commercially available ELISA kit. The obtained results showed that the immunosensor has the potential to be used in clinical diagnosis as a rapid and reliable tool for PSA detection.