Development of a label-free electrochemical aptasensor based on diazonium electrodeposition: Application to cadmium detection in water

Selma Rabai; Messaoud Benounis; Gaëlle Catanante; Abdoullatif Baraket; Abdelhamid Errachid; Nicole Jaffrezic Renault; Jean-Louis Marty; Amina Rhouati

doi:10.1016/j.ab.2020.113956

Development of a label-free electrochemical aptasensor based on diazonium electrodeposition: Application to cadmium detection in water

Anal Biochem. 2021 Jan 1:612:113956. doi: 10.1016/j.ab.2020.113956. Epub 2020 Sep 17.

Authors

Selma Rabai¹, Messaoud Benounis², Gaëlle Catanante³, Abdoullatif Baraket⁴, Abdelhamid Errachid⁴, Nicole Jaffrezic Renault⁴, Jean-Louis Marty⁵, Amina Rhouati⁶

Affiliations

¹ Laboratory of Sensors, Instrumentations and Process (LCIP), University of Khenchela, Khenchela, Algeria. Electronic address: gp.selma@yahoo.fr.
² Laboratory of Sensors, Instrumentations and Process (LCIP), University of Khenchela, Khenchela, Algeria. Electronic address: benounis@yahoo.fr.
³ Laboratory of Biosensors, Analysis and Environment (BAE), University of Perpignan Via Domitia, Perpignan, France. Electronic address: gaelle.catanante@univ-perp.fr.
⁴ Laboratory of Analytical Sciences, University of Claude Bernard 1, Doua 69100 Villeurbanne, Lyon, France.
⁵ Laboratory of Biosensors, Analysis and Environment (BAE), University of Perpignan Via Domitia, Perpignan, France.
⁶ Laboratory of Biosensors, Analysis and Environment (BAE), University of Perpignan Via Domitia, Perpignan, France; Higher National School of Biotechnology, Constantine, Algeria. Electronic address: a.rhouati@ensbiotech.dz.

PMID: 32950496
DOI: 10.1016/j.ab.2020.113956

Abstract

In this study we have developed a new aptasensor for cadmium (Cd²⁺) detection in water. Gold electrode surface has been chemically modified by electrochemical reduction of diazonium salt (CMA) with carboxylic acid outward from the surface. This was used for amino-modified cadmium aptamer immobilization through carbodiimide reaction. Chemical surface modification was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). This latter was also used for Cd²⁺ detection. The aptasensor has exhibited a good linear relationship between the logarithm of the Cd²⁺ concentration and the impedance changes in the range from 10^-3 to 10^-9 M with a correlation R² of 0.9954. A high sensitivity was obtained with a low limit of detection (LOD) of 2.75*10^-10 M. Moreover, the developed aptasensor showed a high selectivity towards Cd²⁺ when compared to other interferences such as Hg²⁺, Pb²⁺ and Zn²⁺. The developed aptasensor presents a simple and sensitive approach for Cd²⁺detection in aqueous solutions with application for trace Cd²⁺ detection in spring water samples.

Keywords: Aptasensor; Cadmium detection; Diazonium electrografting; Gold electrode; Label-free detection.

MeSH terms

Aptamers, Nucleotide / chemistry*
Biosensing Techniques / instrumentation*
Biosensing Techniques / methods
Cadmium / analysis*
Cations / analysis
Diazonium Compounds / chemistry
Dielectric Spectroscopy
Electrochemical Techniques / methods*
Electrodes
Electroplating / methods
Gold / chemistry
Limit of Detection
Reproducibility of Results
Water / analysis*

Substances

Aptamers, Nucleotide
Cations
Diazonium Compounds
Cadmium
Water
Gold