title: A disposable electrochemical immunosensor for prolactin involving affinity reaction on streptavidin-functionalized magnetic particles.
abstract: A novel electrochemical immunosensor was developed for the determination of the hormone prolactin. The design involved the use of screen-printed carbon electrodes and streptavidin-functionalized magnetic particles. Biotinylated anti-prolactin antibodies were immobilized onto the functionalized magnetic particles and a sandwich-type immunoassay involving prolactin and anti-prolactin antibody labelled with alkaline phosphatase was employed. The resulting bio-conjugate was trapped on the surface of the screen-printed electrode with a small magnet and prolactin quantification was accomplished by differential pulse voltammetry of 1-naphtol formed in the enzyme reaction using 1-naphtyl phosphate as alkaline phosphatase substrate. All variables involved in the preparation of the immunosensor and in the electrochemical detection step were optimized. The calibration plot for prolactin exhibited a linear range between 10 and 2000 ng mL(-1) with a slope value of 7.0 nA mL ng(-1). The limit of detection was 3.74 ng mL(-1). Furthermore, the modified magnetic beads-antiprolactin conjugates showed an excellent stability. The immunosensor exhibited also a high selectivity with respect to other hormones. The analytical usefulness of the immnunosensor was demonstrated by analyzing human sera spiked with prolactin at three different concentration levels.
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, University Computense of Madrid, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Moreno-Guzmán
authors.forename: Araceli
authors.initials: A
authors.lastname: González-Cortés
authors.forename: Paloma
authors.initials: P
authors.lastname: Yáñez-Sedeño
authors.forename: José M
authors.initials: JM
authors.lastname: Pingarrón
mesh_terms: D000818:Animals; D001681:Biological Assay / Q000295:instrumentation*; D003429:Cross Reactions; D004209:Disposable Equipment; D004563:Electrochemistry / Q000295:instrumentation*; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation*; D008280:Magnetics; D011388:Prolactin / Q000032:analysis* / Q000097:blood / Q000737:chemistry / Q000276:immunology; D019809:Streptavidin / Q000737:chemistry* / Q000378:metabolism; D014159:Transducers
chemical_list: D011388:Prolactin; D019809:Streptavidin