Journal
BIOSENSORS & BIOELECTRONICS
Volume 24, Issue 7, Pages 2057-2063Publisher
ELSEVIER ADVANCED TECHNOLOGY
DOI: 10.1016/j.bios.2008.10.020
Keywords
Folic acid; Electrochemical immunosensor; Indirect competitive immunoassay; Magnetic beads; Fortified milk
Categories
Funding
- Ministry of Education and Science (MEC), Madrid [BIO2007-63300]
- Universidad Nacional del Litoral (Argentina)
- Funcacion Carolina and Agencia Espanola de Cooperacion Internacional [A/6488/06, A/7927/07]
Ask authors/readers for more resources
An immunoassay-based strategy for folic acid in vitamin-fortified milk with electrochemical detection using magneto sensors is described for the first time. Among direct and indirect competitive formats, best performance was achieved with an indirect competitive immunoassay. The immunological reaction for folic acid (FA) detection was performed, for the first time on the magnetic bead as solid support by the covalent immobilization of a protein conjugate BSA-FA on tosyl-activated magnetic bead. Further competition for the specific antibody between FA in the food sample and FA immobilized on the magnetic bead was achieved, followed by the reaction with a secondary antibody conjugated with HRP (AntiIgG-HRP). Then, the modified magnetic beads were easily captured by a magneto sensor made of graphite-epoxy composite (m-GEC) which was also used as the transducer for the electrochemical detection. The performance of the immunoassay-based strategy with electrochemical detection using magneto sensors was successfully evaluated using spiked-milk samples and compared with a novel magneto-ELISA based on optical detection. The detection limit was found to be of the order of mu g l(-1) (13.1 nmol l(-1), 5.8 mu g l(-1)) for skimmed milk. Commercial vitamin-fortified milk samples were also evaluated obtaining good accuracy in the results. This novel strategy offers great promise for rapid, simple, cost-effective and on-site analysis of biological and food samples. (C) 2008 Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available