Single-walled carbon nanotubes covalently functionalized with cysteine: A new alternative for the highly sensitive and selective Cd(II) quantification

SENSORS AND ACTUATORS B-CHEMICAL

卷:249

Article

Gutierrez, Fabiana A.¹  Miguel Gonzalez-Dominguez, Jose^2,3  Anson-Casaos, Alejandro²  Hernandez-Ferrer, Javier²  Rubianes, Maria D.¹  Martinez, Maria T.²  Rivas, Gustavo¹ 

[1] Univ Nacl Cordoba, Fac Ciencias Quim, Dept Fis Quim, INFIQC, RA-5000 Cordoba, Argentina

[2] CSIC, Inst Carboquim, C Miguel LuesmaCastan 4, E-50018 Zaragoza, Spain

[3] Univ Castilla La Mancha, Fac Chem, MSOC Nanochem Grp, Avda Camilo Jose Cela S-N, E-13071 Ciudad Real, Spain

关键词: Carbon nanotubes;    Electrochemical sensor;    Cadmium;    Complex formation;    Cysteine-functionalized SWCNT;    Covalently functionalization;   

DOI  :  10.1016/j.snb.2017.04.026

来源: Elsevier

【 摘 要 】

This work is focused on the development of an electrochemical sensor for the quantification of Cd(II) based on the use of glassy carbon electrodes (GCE) modified with a dispersion of single-walled carbon nanotubes (SWCNTs) covalently functionalized with cysteine (Cys). Cd(II) is preconcentrated at the electrode surface by complex formation at open circuit potential, followed by the reduction at -0.900 V and the final anodic voltammetric stripping in a 0.020 M acetate buffer solution pH 5.00. The functionalization of SWCNTs was performed through the reaction between the carboxylic groups of oxidized SWCNT and amino groups of S-triphenylmethyl cysteine using a coupling chemistry agent based on benzotriazol for the activation of carboxylic residues. There was a linear relationship between Cd oxidation signal and Cd(II) concentration between 1.0 and 300.0 mu gL(-1) Cd(II), with a sensitivity of (49 +/- 2) x 10(-3) mu A mu g(-1)L and a detection limit of 0.3 mu gL(-1). The reproducibility was 1.7% using the same dispersion and 3.8% using 3 different dispersions. The sensor was challenged with groundwater samples enriched with Cd(II) showing excellent recovery percentages and excellent agreement with the values obtained by ICP-MS. (C) 2017 Elsevier B.V. All rights reserved.

【 授权许可】

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