A highly sensitive disposable amperometric immunosensor based on the use of magnetic beads (MBs) is described for determination of Ara h 1, the major peanut allergen, in only 2h. The approach uses a sandwich configuration involving selective capture and biotinylated detector antibodies and carboxylic acid-modified MBs (HOOC-MBs). The MBs bearing the immunoconjugates are captured by a magnet placed under the surface of a disposable screen-printed carbon electrode (SPCE) and the affinity reactions are monitored amperometrically at -0.20V (vs a Ag pseudo-reference electrode) in the presence of hydroquinone (HQ) as electron transfer mediator and upon addition of H<inf>2</inf>O<inf>2</inf> as the enzyme substrate. The developed immunosensor exhibits a wide range of linearity between 20.8 and 1000.0ngmL<sup>-1</sup> Ara h 1, a detection limit of 6.3ngmL<sup>-1</sup>, a great selectivity, a good reproducibility with a RSD of 6.3% for six different immunosensors and a useful lifetime of 25 days. The usefulness of the immunosensor was demonstrated by determining Ara h 1 in different matrices (food extracts and saliva). The results correlated properly with those provided by a commercial ELISA method offering a reliable and promising analytical screening tool in the development of user-friendly devices for on-site determination of Ara h 1.
|Titolo:||Sensitive and selective magnetoimmunosensing platform for determination of the food allergen Ara h 1|
COSIO, MARIA STELLA (Penultimo)
|Parole Chiave:||Amperometric immunosensor; Ara h 1; Food extracts; Magnetic beads; Saliva; Screen-printed electrode|
|Settore Scientifico Disciplinare:||Settore AGR/15 - Scienze e Tecnologie Alimentari|
|Data di pubblicazione:||20-apr-2015|
|Digital Object Identifier (DOI):||10.1016/j.aca.2015.04.041|
|Appare nelle tipologie:||01 - Articolo su periodico|