Site-directed antibody immobilization using a protein A-gold binding domain fusion protein for enhanced SPR immunosensing

E. de Juan-Franco, A. Caruz, J.R. Pedrajas and L. M. Lechuga

Analyst , 138 (7), 2013, 2023 - 2031 - DOI: 10.1039/c3an36498d

http://pubs.rsc.org/en/Content/ArticleLanding/2013/AN/C3AN36498D

Abstract: We have implemented a novel strategy for the oriented immobilization of antibodies onto a gold surface based on the use of a fusion protein, the Protein A-Gold binding domain (PAG). PAG consists of a gold binding peptide (GBP) coupled to the immunoglobulin-binding domains of the staphylococcal protein A. This fusion protein provides an easy and fast oriented immobilization of antibodies preserving its native structure, while leaving freely exposed the antigen binding sites (Fab). Using this immobilization strategy, we have demonstrated the performance of the immunosensing of the human Growth Hormone by SPR. A limit of detection of 90 ng/mL was obtained with an inter-chip variability lower than 7%. The comparison of this method with other strategies for the direct immobilization of antibodies over gold surfaces has showed the enhanced sensitivity provided by the PAG approach. Keywords: SPR, oriented coupling, protein A, Gold-binding polypeptide

Site-directed antibody immobilization using a protein A-gold binding domain fusion protein for enhanced SPR immunosensing

, ,

Back to Articles List