Metal Enhanced Fluorescence Immunosensor Based on Gold Nanoparticles Array for Early Diagnosis of Prostate Cancer

Prostate cancer stands as the second frequently form of cancer in men. Early and accurate disease diagnosis is crucial, particularly during the initial stages when prostate-specific antigen (PSA) biomarkers are present in low concentrations. Addressing the imperative for efficient detection methods, Metal Enhanced Fluorescence (MEF)-based biosensors emerge as exceptional candidates due to their unmatched sensitivity and precision. In this work, a MEF-based immunosensor integrated with a customized fluidic setup has been developed. The biosensor consists of gold nanoparticles (AuNPs) randomly immobilized onto a glass substrate via an electrostatic self-assembly technique. A sandwich scheme has been employed for PSA recognition, with antibodies as capture bioreceptor covalently immobilized onto the AuNPs surface and a top fluorescently labeled bioreceptor layer. The customized fluidic system ensures a high surface coverage that significantly amplifies the antibody-analyte bindings compared to diffusion. The biosensor has been tested on real samples, successfully detecting PSA in human serum within a rapid 40-minute assay time by reaching a limit of detection (LOD) of 150 pg·mL ^-1 .