297
Views
11
CrossRef citations to date
0
Altmetric
IMMUNOASSAY

Rapid and Sensitive Fluoroimmunoassay Based on Quantum Dots for Detection of Melamine in Milk

, , , , , , , & show all
Pages 275-285 | Received 22 May 2012, Accepted 04 Jul 2012, Published online: 02 Jan 2013
 

Abstract

A rapid and sensitive indirect competitive fluorescence-linked immunosorbent assay (icFLISA) method was developed for detection of melamine in milk based on secondary antibody (Ab2)-conjugated quantum dots (QDs). The sensitivity of icFLISA with a limit of detection (LOD) of melamine (3.88 ng mL−1) and 50% inhibition value (IC50) (31.58 ng mL−1), was much higher than that of icELISA. As a proof of principle, recovery tests involving four fortification levels (150, 80, 40, and 20 ngmL−1) in blank samples were also performed. The recoveries ranged from 80.85 to 110.54% with coefficient of variations (CVs) of 2.82–8.82%. When challenged with authentic samples, these results of icFLISA were consistent with that of icELISA, immuno-chromatographic assay and gas chromatography-single quadruple mass spectrometry (GC-MS)method, indicating that icFLISA can be considered as a new screening method for detection of melamine in milk.

Acknowledgments

J. Wu and F. Xu contributed equally to this work. We gratefully acknowledge grants from the National Natural Science Funds of China (31072171), the Special Fund for Agro-scientific Research in the Public Interest (No. 2012030692), and the Modern Agriculture Industry System Innovation in Beijing City Team, and Program for Changjiang Scholars and Innovative Research Team in University of China (No. IRT0866).

Notes

Note: When IC50 was the lowest, the concentration of Ag and Ab1 was selected for the next step.

a Ratios of coating antigens (dilution-fold) to primary antibody (dilution-fold).

Note:Every point was replicated five times.

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.