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Proximity Hybridization-Regulated Immunoassay for Cell Surface Protein and Protein-Overexpressing Cancer Cells via Electrochemiluminescence.

Authors :
Wang X
Gao H
Qi H
Gao Q
Zhang C
Source :
Analytical chemistry [Anal Chem] 2018 Mar 06; Vol. 90 (5), pp. 3013-3018. Date of Electronic Publication: 2018 Feb 23.
Publication Year :
2018

Abstract

A simple electrochemiluminescence (ECL) immunoassay based on a proximity hybridization-regulated strategy was developed for highly sensitive and specific detection of cell surface protein and protein-overexpressing cancer cells. A biosensor was fabricated by self-assembling a thiolated capture ss-DNA3 (partially hybridize with ss-DNA1 and ss-DNA2) and blocking with 6-mercapto-1-hexanol on a gold electrode surface. Target protein was simultaneously bound by two ss-DNA-tagged antibody probes (DNA1-Ab1 and DNA2-Ab2), while DNA1 and DNA2 were brought in sufficient proximity and hybridized with capture DNA3 on the surface of the biosensor. After ECL signal reagent Ru(phen) <subscript>3</subscript> <superscript>2+</superscript> was intercalated into the hybridized ds-DNAs, ECL measurement was performed in the coreactant solution. A "signal on" proximity hybridization-regulated ECL immunoassay for alpha-fetoprotein (AFP) was developed. The ECL intensity increased with the increase of AFP concentration in the range of 0.05-20.0 ng/mL with a detection limit of 6.2 pg/mL. Moreover, the developed ECL method was successfully used to detect AFP-overexpressing cancer cells (MCF-7 cancer cells as model) with a detection limit of 620 cells/mL (∼60 MCF-7 cells in 100 μL of cell suspension) and discriminate AFP expression on different types of the living cell surface. This work for the first time reports a proximity hybridization-regulated ECL immunoassay for the detection of the cell surface protein on a living cell surface with good specificity and sensitivity. This simple, specific, and sensitive strategy is greatly promising for the detection of proteins and specific cells.

Details

Language :
English
ISSN :
1520-6882
Volume :
90
Issue :
5
Database :
MEDLINE
Journal :
Analytical chemistry
Publication Type :
Academic Journal
Accession number :
29433314
Full Text :
https://doi.org/10.1021/acs.analchem.7b04359