Optimisation of immuno-gold nanoparticle complexes for antigen detection

van der Heide, Susan and Russell, David A. (2016) Optimisation of immuno-gold nanoparticle complexes for antigen detection. Journal of Colloid and Interface Science, 471. pp. 127-135. ISSN 0021-9797

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Abstract

The aim of this investigation was to define the optimum method of binding antibodies to the surface of gold nanoparticles (AuNPs) and then to apply the optimised antibody-functionalised AuNPs for the detection of a target antigen. A detailed investigation of three different techniques for the functionalisation of AuNPs with anti-cocaine antibody and methods for the subsequent characterisation of the antibody-functionalised AuNP are reported. The addition of anti-cocaine antibody onto the AuNP surface was facilitated by either: a polyethylene glycol (PEG) linker with a –COOH terminal functional group; an aminated PEG ligand; or an N-succinimidyl 3-(2-pyridyldithio)-propionate (SPDP)-Protein A/G intermediate. Characterisation of the functionalised particles was performed using transmission electron microscopy, UV-Visible spectrophotometry and by agarose gel electrophoresis. In addition, the cocaine binding efficacy of the resultant AuNPs and their cocaine-binding capacity was determined using a cocaine-horseradish peroxidase conjugate, and by the application of a microtiter plate-based immunoassay. The results showed that the number of antibody per particle was the highest when the AuNP were functionalised with the Protein A/G intermediate. As compared to free antibody, the cocaine binding efficacy was significantly enhanced using the AuNP-Protein A/G-antibody complex. This optimal antibody-antigen binding efficacy is thought to be the result of the large number of antibody per particle and the oriented binding of the antibody to the Protein A/G on the AuNP surface. These results highlight the ideal immuno-gold nanoparticle characteristics for the detection of target antigens such as cocaine.

Item Type:	Article
Uncontrolled Keywords:	gold nanoparticles,antibodies,conjugation,cocaine
Faculty \ School:	Faculty of Science > School of Chemistry (former - to 2024)
UEA Research Groups:	Faculty of Science > Research Groups > Physical and Analytical Chemistry (former - to 2017)
Depositing User:	Pure Connector
Date Deposited:	22 Mar 2016 09:37
Last Modified:	31 Oct 2024 00:39
URI:	https://ueaeprints.uea.ac.uk/id/eprint/57823
DOI:	10.1016/j.jcis.2016.03.001

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