Engineering WS2–Au–HRP-assisted multiple signal amplification strategy for chemiluminescence immunoassay of prostate specific antigen

A novel chemiluminescence (CL) immunosensor using functionalized tungsten disulfide nanosheets (WS2 NSs)–gold nanoparticles (Au NPs)–horseradish peroxidase (WS2–Au–HRP) as multiple signal amplification probe was developed for prostate specific antigen (PSA) analysis. The WS2–Au nanocomposites were synthesized by in situ growth of Au NPs on the surface of WS2 NSs. HRP and antibody for recognizing the target were subsequently functionalized on WS2–Au. Owing to the large loading capacity of the WS2 NSs, the WS2–Au–HRP nanoprobe exhibits synergistic enhancement to the luminol–H2O2 CL system. The kinetics and spectra of CL from the luminol–H2O2–WS2–Au–HRP system were studied and the CL mechanism is discussed. Exemplified by PSA as target, the ultrasensitive CL immunoassay of PSA was achieved owing to the multiple signal amplification of the WS2–Au–HRP nanoprobe. The detection limit is 3.0 × 10−14 g mL−1 with a linear range of 1.0 × 10−13 to 1.0 × 10−8 g mL−1. Furthermore, the method was applied to human serum sample analysis with high selectivity and reproducibility. The method provides a novel ultrasensitive CL detection tool for biomarkers in real samples.