Fluorescent immunosorbent assay for the detection of alpha lactalbumin in dairy products with monoclonal antibody bioconjugated with CdSe/ZnS quantum dots

Food Chem. 2014 May 1:150:73-9. doi: 10.1016/j.foodchem.2013.10.137. Epub 2013 Nov 4.

Abstract

In this work, a new method termed competitive fluorescence-linked immunosorbent assay (FLISA) was developed for specifically quantification of bovine α-lactalbumin (α-La) in dairy products. The monoclonal antibodies (mAbs) against α-La were produced through hybridoma technology, and the mAbs were covalently conjugated with the CdSe/ZnS quantum dots (QDs) using the crossing-linking reagents. Moreover, a competitive FLISA based on QD-mAb conjugates was established to detect α-La in dairy products. It was shown that there was a good linear relationship between inhibition efficiency, and logarithm of α-La concentration after the detection parameters were optimised in which the concentration of α-La varied from 0.1 to 1000ng/mL. The value of IC50 was 0.03μg/mL, and the FLISA method exhibited high sensitivity with the LOD at 0.1ng/mL. The developed FLISA has been successfully applied to determine α-La in commercial dairy products, providing more sensitive analysis compared with the ELISA method.

Keywords: Fluorescence-linked immunosorbent assay; Milk allergens; Monoclonal antibody; Quantum dots; α-Lactalbumin.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Monoclonal / chemistry*
  • Cattle
  • Dairy Products / analysis*
  • Enzyme-Linked Immunosorbent Assay / instrumentation
  • Enzyme-Linked Immunosorbent Assay / methods*
  • Fluorescence
  • Immunosorbents / chemistry*
  • Lactalbumin / analysis*
  • Quantum Dots / chemistry

Substances

  • Antibodies, Monoclonal
  • Immunosorbents
  • Lactalbumin