Electrochemical Microbead-Based Immunoassay Using an (η5-Cyclopentadienyl)tricarbonylmanganese Redox Marker Bound to Bovine Serum Albumin

• Published in: Langmuir Vol. 22; no. 1; pp. 506 - 511
• Main Authors: Hromadová, Magdaléna, Salmain, Michèle, Fischer-Durand, Nathalie, Pospíšil, Lubomír, Jaouen, Gérard
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 03.01.2006
• Subjects: Analytical chemistry; Animals; Cattle; Chemical Sciences; Chemistry; Electrochemistry; Enzyme-Linked Immunosorbent Assay; Exact sciences and technology; General and physical chemistry; Immunoassay - methods; In Vitro Techniques; Manganese - chemistry; Organometallic Compounds - chemistry; Oxidation-Reduction; Serum Albumin, Bovine - analysis; Serum Albumin, Bovine - chemistry; Surface complex; Immunoglobulins; Separation; Bovine; Antibody; Serum albumin; Antigen; Chemical reduction; Vertebrata; Mammalia; Electrochemistry; Artiodactyla; Solid phase; Impedance; Ungulata; Diameter; Electrons
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/la052188b

A first example of the solid-phase immunoassay of a high-weight antigen bovine serum albumin (BSA) using an (η5-cyclopentadienyl)tricarbonylmanganese (cymantrene) redox probe is presented. The electrochemical detection is based on the impedance measurements of a one-electron reversible reduction of the organometallic probe. The microbead-based immunoassay is discussed for two types of microbeads with different diameters (2.5 and 90 μm) and capabilities to bind the immunoglobulins (2.4 and 10 μg/mg of beads). The use of larger agarose microbeads allows the formation of an antigen−antibody complex at the surface of microbeads directly dispersed in the analyzed solution. No additional separation step is necessary for the electrochemical competitive immunoassay analysis of BSA. The presence of agarose beads in the analyzed solution has no effect on the electrochemical signal from labeled BSA released from the antigen−antibody complex.