Directed self-assembly of gold binding polypeptide-protein A fusion proteins for development of gold nanoparticle-based SPR immunosensors
- Authors
- Ko, Sungho; Park, Tae Jung; Kim, Hyo-Sop; kim, Jae-Ho; Cho, Yong-Jin
- Issue Date
- Apr-2009
- Publisher
- ELSEVIER ADVANCED TECHNOLOGY
- Keywords
- Surface plasmon resonance; Immunosensor; Gold nanoparticle; Fusion protein; Gold binding polypeptides; Protein A
- Citation
- BIOSENSORS & BIOELECTRONICS, v.24, no.8, pp 2592 - 2597
- Pages
- 6
- Journal Title
- BIOSENSORS & BIOELECTRONICS
- Volume
- 24
- Number
- 8
- Start Page
- 2592
- End Page
- 2597
- URI
- https://scholarworks.bwise.kr/cau/handle/2019.sw.cau/27827
- DOI
- 10.1016/j.bios.2009.01.030
- ISSN
- 0956-5663
1873-4235
- Abstract
- Effective immobilization of antibodies on a sensing platform and sensitivity enhancement are crucial in designing surface plasmon resonance (SPR) immunosensors. Colloidal gold nanoparticles (AuNPs) were directly assembled onto a surface of SPR Au chip via 2-aminoethanethiol for the enhancement of sensitivity as a label-free detection system. SEM image showed most AuNPs were uniformly distributed over the surface. A novel fusion protein was constructed by genetically fusing gold binding polypeptides (GBP) to protein A (ProA) as a crosslinker for effective immobilization of antibodies. The resulting GBP-ProA protein was directly self-immobilized onto both bare and AuNPs-assembled SPR chip surfaces via the GBP portion, followed by the oriented binding of human immunoglobulin G (hlgG) onto the ProA domain targeting the Fc region of antibodies and anti-hlgG in series. Furthermore, anti-Salmonella antibodies were immobilized onto both GBP-ProA layered chips for detection of Salmonella typhimurium. SPIR analyses indicated the signal increases for successive binding of hIgG and anti-hIgG onto the GBP-ProA layered AuNPs-assembled chip were higher (about 92 and 30%, respectively) than that onto the identically treated bare chip. This signal enhancement in the AuNPs-assembled chip also caused a 10-fold increased sensitivity in detection of S. typhimurium compared to the bare one. These results demonstrate the direct assembly of AuNPs onto a SPR chip could enhance the signal in biomolecular interaction events, and the GBP-ProA protein could be a valuable crosslinker for simple and oriented immobilization of antibodies onto Au chip surfaces without any surface chemical modification. (c) 2009 Elsevier B.V. All rights reserved.
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Collections - College of Natural Sciences > Department of Chemistry > 1. Journal Articles
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