Enzyme-less electrochemical displacement heterogeneous immunosensor for diclofenac detection.
Biosens Bioelectron
; 97: 246-252, 2017 Nov 15.
Article
en En
| MEDLINE
| ID: mdl-28605688
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.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Contaminantes Químicos del Agua
/
Agua Potable
/
Diclofenaco
/
Anticuerpos Inmovilizados
/
Técnicas Electroquímicas
Tipo de estudio:
Diagnostic_studies
/
Evaluation_studies
Idioma:
En
Revista:
Biosens Bioelectron
Asunto de la revista:
BIOTECNOLOGIA
Año:
2017
Tipo del documento:
Article
País de afiliación:
Vietnam