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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Silver oxide nanoparticles in reduced graphene oxide modified electrode for amino acids electrocatalytic oxidation

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Romeiro Azevedo, Victor Hugo [1] ; da Silva, Jose Luiz [1] ; Stradiotto, Nelson Ramos [1, 2, 3]
Total Authors: 3
[1] Sao Paulo State Univ UNESP, Inst Chem, BR-14800060 Araraquara, SP - Brazil
[2] Sao Paulo State Univ UNESP, Bioenergy Res Inst, BR-13500230 Rio Claro, SP - Brazil
[3] Fluminense Fed Univ UFF, Sch Met & Ind Engn, BR-27255125 Volta Redonda, RJ - Brazil
Total Affiliations: 3
Document type: Journal article
Source: JOURNAL OF ELECTROANALYTICAL CHEMISTRY; v. 845, p. 57-65, JUL 15 2019.
Web of Science Citations: 1

A glassy carbon electrode (GCE) modified with reduced graphene oxide (RGO) and silver oxide nanoparticles (AgNPs-RGO/GCE) was prepared for electrocatalytic oxidation of amino acids. The modified electrode surface was characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy and Raman spectroscopy. The results showed that the developed AgNPs had a medium diameter of 10 +/- 2 nm besides being well dispersed on the RGO surface. The electrochemical behavior of the AgNPs-RGO/GCE in the oxidation of glycine, alanine, leucine, aspartic and glutamic acids was carried out by cyclic voltammetry and amperometric techniques. Voltammetric studies indicated a rise in the anodic peak of the silver (III) oxide species in the presence of amino acids. Essentially, this shows that amino acids were oxidized in the redox mediator was electrodeposited on the electrode surface via an electrocatalytic process. Based on Laviron's equation, the values of a and k(s) for the redox species were found to be 0.51 and 0.61 s(-1), respectively. The catalytic rate constants of 1.4 x 10(8) (alanine) to 5.4 x 10(8) cm(3) mol(-1) s(-1) (glycine), the transfer coefficients 0.37 (leucine) to 0.45 (glutamic acid), and the diffusion coefficients of 1.1 x 10(-6) (alanine) to 7.7 x 10(-6) cm(2) s(-1) (glycine) for the amino acids are reported. The excellent electrocatalytic activity, high sensitivity and good stability observed in our investigation renders the AgNPs-RGO/GCE promising for application as a suitable sensor for amino acids detection. (AU)

FAPESP's process: 14/23846-5 - New methods for determination of carboxylic acids, amino acids and polyols in vinasse of the manufacturing process of ethanol
Grantee:Nelson Ramos Stradiotto
Support Opportunities: Program for Research on Bioenergy (BIOEN) - Regular Program Grants