A washing-/enzyme-free chemiluminescent immunoassay for rapid and sensitive on-site detection of prostate specific...

The abnormal expression of biomarkers is often closely related to the occurrence and development of diseases. Quantification of biomarkers is critical for disease diagnosis, treatment guidance, and prognosis evaluation. Herein, we presented a washing-/enzyme-free chemiluminescent immunoassay (CLIA) for rapid and sensitive on-site detection of prostate specific antigen (PSA). The gold magnetic nanoparticles (Au@MNPs) modified with capture antibody (Ab₁) ensured specific capturing and effective enrichment of PSA in biological matrices via magnetic separation. Meanwhile, the peroxidase-like activity of Au@MNPs enabled the generation of chemiluminescence signals. The entire protocol is washing-/enzyme-free, thus simplifying the analysis process, reducing accumulative errors and overcoming the high cost and instability of natural enzymes. The analytical performance was evaluated to be satisfactory by using a highly integrated detection platform, and the limit of detection (LOD) was as low as 0.41 pg mL^-1. Therefore, this approach proposed a rapid and sensitive on-site detection method for biomarkers, which is of great significance for disease screening in resource-poor settings.