Gold-coated magnetic particles used in improved immunoassays

ANYL 185

Hairong Zhang, Department of Chemistry, University of Michigan, 930 N UNIVERSITY AVE, Ann Arbor, MI 48109 and Mark E. Meyerhoff, mmeyerho@umich.edu, Department of Chemistry, The University of Michigan, 930 N. University Ave., Ann Arbor, MI 48109-1055.
Magnetic particles have been widely used as solid phases in immunoassays. Conventionally, antibodies are either covalently bonded or adsorbed to the polymeric coating of the solid phase, in which randomly oriented antibodies are immobilized, leading to heterogeneous binging constants. In this work, to achieve better orientation control of the immobilized antibodies, gold-coated magnetic particles are prepared and used as a solid phase for developing a sandwich type enzyme immunoassay to detect C-reactive protein. Gold-coated magnetic particles are prepared through an electroless plating method and characterized. Fab's fragments of a desired capture antibody population are immobilized on the gold-coated magnetic particles via a thiol-Au bond. It is shown that more active antibody is bound to the gold coated particles than conventional magnetic phases in which the same amount of total antibody binding sites are attached randomly. Results demonstrate that gold-coated magnetic particles provide enhanced antibody binding efficiencies and a lower detection limit for the measurement of C-reaction protein.
 

General Papers
7:00 PM-9:00 PM, Sunday, 28 August 2005 Washington DC Convention Center -- Hall A, Poster

Sci-Mix
8:00 PM-10:00 PM, Monday, 29 August 2005 Washington DC Convention Center -- Hall A, Sci-Mix

Division of Analytical Chemistry

The 230th ACS National Meeting, in Washington, DC, Aug 28-Sept 1, 2005