Functionalization of amorphous carbon nitrogenated thin film electrodes for improved detection of cadmium vs. copper cations
The specificity of a sensor relative to specific cations can be modified by functionalization of a nitrogenated amorphous carbon thin film (a-C:Nx) electrode. This surface modification was performed through the reduction of diazonium salts presenting different functional groups which interact with ions in solution. Cyclic voltammetry from +0.3 to -1.0 V vs. SCE was used for the grafting process leading to the formation of covalent C-C bonds onto the film surface. The precursor concentration and number of cycles were optimized and correlated to the specificity and sensitivity for copper and/or cadmium ion detection. The coverage of the electrode was checked by infrared absorption (IR) spectroscopy, contact angle and cyclic
voltammetry measurements using the Fe(CN)63-/4- system and showed that the grafting of diazonium salt was effective on the surface of the a-C:Nx electrode. A greater sensitivity of
the electrode to Cd2+ was observed for the highest concentrations of grafting salts (4-aminobenzene carboxylic acid (4-ABA)). Moreover, a marked decrease of cadmium sensitivity is
noted after grafting and we observed a lower influence of the Cu2+ presence on the Cd2+ signal, giving way to a better specificity of these functionalized sensors.
Auteur(s) : Serigne Massamba Seck, Stéphane Charvet, Modou Fall, Emmanuel Baudrin, Florence Geneste, Michaël Lejeune, Mohammed Benlahsen
Pages : 154-161
Année de publication : 2015
Revue : Journal of Electroanalytical Chemistry
N° de volume : 738
Type : Article
Statut Editorial : International Peer-reviewed Journal also devoted to All Physicochemical Aspects of Fundamental and Applied Electrochemistry.
Mise en ligne par : FALL Modou