Title: Improvement of a pesticide immunosensor performance using site-directed antibody immobilisation and carbon nanotubes

Authors: Mouna Marrakchi; Saloua Helali; Juan Soto Camino; Miguel Angel González-Martínez; Adnane Abdelghani; Moktar Hamdi

Addresses: Laboratoire d'Ecologie et de Technologie Microbienne, Centre Urbain Nord, University of Carthage, INSAT, BP676, 1080 Charguia Cedex, Tunisia ' Research and Technology Centre of Energy, B.P N 95 2050, Hammam Lif, Tunisia ' Departamento de Quimica, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia, Spain ' Departamento de Quimica, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia, Spain ' Nanotechnology Laboratory, Centre Urbain Nord, University of Carthage, INSAT, 1080 Charguia Cedex, Tunisia ' Laboratoire d'Ecologie et de Technologie Microbienne, Centre Urbain Nord, Carthage University, INSAT, BP676, 1080 Charguia Cedex, Tunisia

Abstract: The potential toxicity of pesticide residues in drinking water has meant a rigid regulation for the appearance of these pollutants. Thus, in this work, we developed a new immunosensor for atrazine detection. We focused on the optimisation of the antibody immobilisation method on sensor surface for the enhancement of the biosensor sensitivity. First, with site-directed immobilisation of rabbit anti-atrazine antibodies using goat anti-rabbit immunoglobulin, a detection limit of 0.5 ng/mL was obtained. This value is 20 times lower than the detection limit obtained with non-oriented antibodies. The second way to improve immunosensor sensitivity consisted of the addition of carbon nanotubes (CNT). As result of using these CNT, detection limit has been improved again from 0.5 ng/mL to 100 pg/mL.

Keywords: immunosensors; pesticides; carbon nanotubes; CNTs; oriented antibodies; atrazine detection; impedance spectroscopy; immunosensor performance; antibody immobilisation; toxicity; pesticide residues; drinking water; water pollution; water quality; nanotechnology; sensors; biosensors.

DOI: 10.1504/IJNT.2013.053519

International Journal of Nanotechnology, 2013 Vol.10 No.5/6/7, pp.496 - 507

Published online: 27 Apr 2013 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article