Sensors, Vol. 22, Pages 105: Fabrication of AuNPs/MWCNTS/Chitosan Nanocomposite for the Electrochemical Aptasensing of Cadmium in Water

Sensors, Vol. 22, Pages 105: Fabrication of AuNPs/MWCNTS/Chitosan Nanocomposite for the Electrochemical Aptasensing of Cadmium in Water Sensors doi: 10.3390/s22010105 Authors: Selma Rabai Ahlem Teniou Gaëlle Catanante Messaoud Benounis Jean-Louis Marty Amina Rhouati Cadmium (Cd2+) is one of the most toxic heavy metals causing serious health problems; thus, designing accurate analytical methods for monitoring such pollutants is highly urgent. Herein, we report a label-free electrochemical aptasensor for cadmium detection in water. For this, a nanocomposite combining the advantages of gold nanoparticles (AuNPs), carbon nanotubes (CNTs) and chitosan (Cs) was constructed and used as immobilization support for the cadmium aptamer. First, the surface of a glassy carbon electrode (GCE) was modified with CNTs-CS. Then, AuNPs were deposited on CNTs-CS/GCE using chrono-amperometry. Finally, the immobilization of the amino-modified Cd-aptamer was achieved via glutaraldehyde cross-linking. The different synthesis steps of the AuNPs/CNTs/CS nano assembly were characterized by cyclic voltammetry (CV). Electrochemical impedance spectroscopy (EIS) was employed for cadmium determination. The proposed biosensor exhibited excellent performances for cadmium detection at a low applied potential (−0.5 V) with a high sensitivity (1.2 KΩ.M−1), a detection limit of 0.02 pM and a wide linear range (10−13–10&am...
Source: Sensors - Category: Biotechnology Authors: Tags: Article Source Type: research