ELABORATION ET CARACTERISATION DE BIOCAPTEURS ET DE BOIPUCES A ADN ELECTROCHIMIQUES SELECTIFS POUR LA DETECTION DU CADMIUM DANS LES EAUX DE SURFACE
No Thumbnail Available
Date
2021
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abbes Laghrour University- Khenchela
Abstract
Our work was adressed to the development of two electrochemical aptasensors for the Cadmium
ions detection in real water samples.
In the first place, the first aptasensor was developed based on a Gold electrode chemically modified
by the electrochemical reduction of the Diazonium salt (CMA) and carboxylic acid, on which an
amino-modified aptamer-Cadmium was immobilized by the Carbodiimide reaction. This biosensor
showed a linear range of 10
-3
to 10
-9
M of Cadmium with a limit of detection (LOD) of 2.75*10
.
High selectivity was obtained during interference measurements in the presence of Hg
and
Zn
2+
. This platform allows also a promising application on samples of spring water in Khenchela
(Algeria).
Then, another aptasensor was put in place through the modification of a Glassy Carbon electrode
with nanotubes of Carbon-Chitosan (CNTs-CS), then with Gold nanoparticles electro-deposited
(AuNPs) on the CNTs-CS, and then immobilization of aptamer-Cadmium via glutaraldehyde.
Among the conditions for optimization, an immobilization time of 2 hours, a pH of 4.5, a
temperature of 25 °C and an aptamer concentration of 0.75 µM. This biosensor demonstrates high
sensitivity of 1.2 KΩ.M
-1
, a large linear range 10
-13
–10
-4
M and a detection limit of 0.02 pM with
good selectivity towards Cadmium.