Related Experiment Video
Updated: Dec 8, 2025

An Anaerobic Biosensor Assay for the Detection of Mercury and Cadmium
Published on: December 17, 2018
Development of a label-free electrochemical aptasensor based on diazonium electrodeposition: Application to cadmium
Selma Rabai1, Messaoud Benounis1, Gaëlle Catanante2
1Laboratory of Sensors, Instrumentations and Process (LCIP), University of Khenchela, Khenchela, Algeria.
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.
Related Concept Videos
Electrodeposition
Electrodeposition can...
Voltammetry: Stripping Methods
Anodic Stripping Voltammetry (ASV)
ASV is used to determine metals and metalloids at trace levels. It involves two steps: deposition and stripping. First, a negative potential is applied to the...
Effects of EDTA on End-Point Detection Methods
In the visual method, metal-ion indicators (metallochromic dyes), which have distinct colors in their free and complex forms, are added to the mixture to signal the titration's end point. They form stable complexes with metal ions, but these complexes are weaker than the corresponding metal–EDTA complexes. As a...
Amperometry: Overview

