Format

Send to

Choose Destination
Biosens Bioelectron. 2017 Nov 15;97:246-252. doi: 10.1016/j.bios.2017.06.010. Epub 2017 Jun 7.

Enzyme-less electrochemical displacement heterogeneous immunosensor for diclofenac detection.

Author information

1
Univ. Paris Diderot, Sorbonne Paris Cité, ITODYS, UMR 7086 CNRS, 15 rue J-A de Baïf, 75205 Paris Cedex 13, France; USTH - Université des Sciences et Technologies de Hanoï, Nghĩa Đô, Cầu Giấy, Hanoi, Vietnam.
2
USTH - Université des Sciences et Technologies de Hanoï, Nghĩa Đô, Cầu Giấy, Hanoi, Vietnam.
3
Univ. Paris Diderot, Sorbonne Paris Cité, ITODYS, UMR 7086 CNRS, 15 rue J-A de Baïf, 75205 Paris Cedex 13, France.
4
Department of Inorganic Chemistry, School of Chemical Engineering, Hanoi University of Science and Technology (HUST), 1st Dai Co Viet Road, Hanoi, Vietnam.
5
Graduate University of Science and Technology, Vietnam Academy of Science and Technology, 18, Hoang Quoc Viet, Hanoi, Vietnam; Center for High Technology Development, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Hanoi, Vietnam.
6
Univ. Paris Diderot, Sorbonne Paris Cité, ITODYS, UMR 7086 CNRS, 15 rue J-A de Baïf, 75205 Paris Cedex 13, France. Electronic address: piro@univ-paris-diderot.fr.

Abstract

We describe an electrochemical immunosensor based on functionalization of a working electrode by electrografting two functional diazonium salts. The first one is a molecular probe, diclofenac, coupled with an arylamine onto which a specific antibody is immobilized by affinity interactions; the second is a redox probe (a quinone) also coupled with an arylamine, able to transduce the hapten-antibody association into a change in electroactivity. The steric hindrance induced by the antibody leads to a current decrease upon binding of the antibody on the grafted molecular probe; conversely, when diclofenac is present in solution, a displacement equilibrium occurs between the target diffusing into the solution and the grafted probe. This leads to dissociation of the antibody from the electrode surface, event which is transduced into a current increase ("signal-on" detection). The detection limit is ca. 20 fM, corresponding to 6pgL-1 diclofenac, which is competitive compared to other label-free immunosensors. We demonstrate that the sensor is selective and is able to quantify diclofenac in tap water.

KEYWORDS:

Diazonium salts; Diclofenac; Displacement immunoassay; Electrochemical Immunosensor; Hapten probe

PMID:
28605688
DOI:
10.1016/j.bios.2017.06.010
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center