Type

Journal Article

Authors

David E Williams
Brian D Maccraith
Richard O'Kennedy
Katherine Heydon
Barry McDonnell
Stephen Hearty
Robert Nooney
Carol Crean née Lynam
Vladimir Gubala

Subjects

Microbiology

Topics
dendrimers genetics recombinant proteins metabolism pamam starburst single chain antibodies nanoparticles immunoassay kinetics chemistry immunology

Kinetics of immunoassays with particles as labels: effect of antibody coupling using dendrimers as linkers. (2011)

Abstract In this article, we report on poly(amidoamine) dendrimers (PAMAM) as coupling agents for recombinant single-chain (ScFv) antibodies to nanoparticle (NP) labels, for use in immunoassay. We present a simple theory for the kinetics of particle capture onto a surface by means of an antibody-antigen reaction, in which the important parameter is the fraction of the particle surface that is active for reaction. We describe how increasing the generation number of the linking dendrimers significantly increased the fraction of the NP surface that is active for antigen binding and consequently also increased the assay kinetic rates. Use of dendrimers for conjugation of the NP to the antibody resulted in a significantly higher surface coverage of active antibody, in comparison with mono-valent linker chemistry. As a direct consequence, the increase in effective avidity significantly out-weighed any effect of a decreased diffusion coefficient due to the NP, when compared to that of a molecular dye-labelled antibody. The signal to noise ratio of the G4.5 dendrimer-sensitised nanoparticles out-performed the dye-labelled antibody by approximately four-fold. Particle aggregation experiments with the multi-valent antigen CRP demonstrated reaction-limited aggregation whose rate increased significantly with increasing generation number of the dendrimer linker.
Collections Ireland -> Dublin City University -> PubMed

Full list of authors on original publication

David E Williams, Brian D Maccraith, Richard O'Kennedy, Katherine Heydon, Barry McDonnell, Stephen Hearty, Robert Nooney, Carol Crean née Lynam, Vladimir Gubala

Experts in our system

1
David E Williams
Dublin City University
Total Publications: 18
 
2
R O'Kennedy
Dublin City University
Total Publications: 197
 
3
Stephen Hearty
Dublin City University
Total Publications: 27
 
4
Robert Nooney
Dublin City University
Total Publications: 12
 
5
Vladimir Gubala
Dublin City University
Total Publications: 17