Amperometric immunosensor for prolactin hormone measurement using antibodies loaded on a nano-Au monolayer modified ionic liquid carbon paste electrode

The fabrication of a novel electrochemical immunosensor for rapid and precise determination of prolactin was carried out using carbon paste electrode (CPE) consist of ionic liquid (IL) and graphite. Gold nanoparticles were employed as a modifier on the surface of CPE to immobilize the prolactin antibody (anti-PRL). The immunoassay was set up by sandwiching the antigen between prolactin antibody and the polyclonal anti-human-prolactin antibody labeled with horseradish peroxidase (HRP-labeled anti-PRL) as secondary antibody, on the surface of modified CPE. The reaction between O-aminophenol (OAP) and H2O2 which is catalyzed by labeled HRP on the sandwich immunosensor generate a signal in differential pulse voltammetry (DPV) that is used to determine the concentration of prolactin. This immunosensor provides the measurement of prolactin concentration in a linear range of 25.0–2000.0 mIU L−1 with a detection limit 12.5 mIU L−1. Moreover, it is applicable in the clinical assay of prolactin due to its high sensitivity and acceptable stability. A novel amperometric immunosensor for prolactin hormone measurement was constructed. [Display omitted] •A carbon paste electrode was modified with antibody, nano-Au monolayer and ionic liquid.•This electrode was used as an amperometric immunosensor for prolactin hormone measurement.•It measured this hormone very sensitive and selective.