1. Harnessing immunomagnetic separation and quantum dot-based quantification capacities for the enumeration of absolute levels of biomarker
- Author
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Kwan Hyi Lee, Hoyoung Park, Jonghoon Choi, Jong-Wook Lee, and Mintai P. Hwang
- Subjects
Analyte ,New materials ,Bioengineering ,Immunomagnetic separation ,Limit of Detection ,Quantum Dots ,Enumeration ,Animals ,General Materials Science ,Electrical and Electronic Engineering ,Chromatography ,biology ,Absolute number ,Chemistry ,Immunomagnetic Separation ,Mechanical Engineering ,Antibodies, Monoclonal ,General Chemistry ,C-Reactive Protein ,Models, Chemical ,Mechanics of Materials ,Quantum dot ,biology.protein ,Magnets ,Biomarker (medicine) ,Cattle ,Protein G ,Biomarkers - Abstract
The field of biomarker quantification has experienced a growth parallel to the discovery of new materials. In this paper, we propose an innovative system for the separation and quantification of biomarkers using a simple magnetic bead (MB)–quantum dot (QD) sandwich assay. The basis of the system lies in the interaction between histidine residues on protein G and Ni ions on QDs, and the use of imidazole to selectively detach QDs bound to target biomarkers, in effect enumerating the absolute number of biomarker units. We used C-reactive protein (CRP) as a proof-of-concept and demonstrated a detection sensitivity of 82.5 fmoles in 50 μl of sample volume, a commonly used analytical volume (e.g. ELISA). Although CRP was used as a model to conduct this study, the sensitivity and simplicity of this detachable system make it a viable approach in the quantification of other target analytes.
- Published
- 2013