Antifouling Surface Layers for Improved Signal-to-Noise of Particle-Based Immunoassays

Chen, A., Kozak, D., Battersby, B.J., Forrest, R.M., Scholler, N., Urban, N. and Trau, M. (2009) Antifouling Surface Layers for Improved Signal-to-Noise of Particle-Based Immunoassays. Langmuir, 25 23: 13510-13515. doi:10.1021/la903148n

Author Chen, A.
Kozak, D.
Battersby, B.J.
Forrest, R.M.
Scholler, N.
Urban, N.
Trau, M.
Title Antifouling Surface Layers for Improved Signal-to-Noise of Particle-Based Immunoassays
Journal name Langmuir   Check publisher's open access policy
ISSN 0743-7463
Publication date 2009-12-01
Year available 2009
Sub-type Article (original research)
DOI 10.1021/la903148n
Volume 25
Issue 23
Start page 13510
End page 13515
Total pages 6
Editor David G Whitten
Place of publication United States
Publisher American Chemical Society
Collection year 2010
Language eng
Subject C1
Formatted abstract
A 10-fold improvement in the signal-to-noise (S/N) ratio of an optically encoded silica particle-based immunoassay was achieved through incorporating a protein resistant poly(ethylene glycol) (PEG) surface layer and optimizing antibody immobilization conditions. PEG was activated using 2,2,2-trifluoroethanesulfonyl chloride (tresyl) and required a minimum reaction time of 1.5 h. The activated PEG had a reactive half-life of approximately 5 h when stored in acidified dimethyl sulfoxide (DMSO). By increasing the protein incubation time and concentration, a maximum antibody loading on the particle surface of 1.6 x 10(-2) Molecules per nm(2) was achieved. The assay S/N ratio was assessed using a multiplexed multicomponent optically encoded species-specific imrnunoassay. Encoded particles were covalently grafted or nonspecifically coated with either bovine or mouse IgG for the simultaneous detection of complementary anti-IgG "target" or uncomplementary anti-IgG "noise". The versatility and potential as a serum-based assay platform was demonstrated by immobilizing either a polyclonal antibody or an engineered single-chain variable fragment (scFv) capture probe on particles for the detection of the ovarian cancer biomarker, mesothelin (MSLN). The MLSN antigen was spiked into PBS buffer or 50% human serum, Both capture probe orientations, and media conditions showed similar low level detection limits of 5 ng/mL; however, a 40% decrease in maximum signal intensity was observed for assays run in 50% serum. © Langmuir 2009
Q-Index Code C1
Q-Index Status Confirmed Code

Document type: Journal Article
Sub-type: Article (original research)
Collections: 2010 Higher Education Research Data Collection
Australian Institute for Bioengineering and Nanotechnology Publications
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Citation counts: TR Web of Science Citation Count  Cited 15 times in Thomson Reuters Web of Science Article | Citations
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Created: Sun, 06 Dec 2009, 00:04:32 EST