title: Carbon nanoparticles with tosyl functional group for distinguishing voltammetric peaks of ascorbic acid and uric acid.
abstract: In this approach, electro-oxidation of a mixture of uric acid and ascorbic acid at the surface of tosyl surface carbon nanoparticles/glassy carbon electrode has been performed. The electro-oxidation of these compounds at bare electrode is sluggish and there is no suitable peak separation between them. However, using functionalized carbon nanoparticles, two well-defined anodic peaks with a considerable enhancement in the peak current and a remarkable peak potential separation near 452 mV is obtained. The porous interfacial layer of the carbon nanoparticles modified electrode with a high specific surface area increases the conductive area; molecules can penetrate through the conductive porous channels onto the electrode more easily so leading to higher sensitivity and selectivity. The dynamic linear ranges of 1.0 × 10(-5) to 3.0 × 10(-3)M and 1.0 × 10(-7) to 1.0 × 10(-4)M with detection limits 1.0 × 10(-5)M and 2.0 × 10(-8)M (for S/N=3) were obtained for ascorbic acid and uric acid, respectively. Analytical utility of the modified electrode has been examined successfully using human urine samples and vitamin C commercial tablets.
authors.affiliation: Department of Chemistry, University of Mohaghegh Ardabili, Ardabil, Iran. Electronic address: mandanaamiri@uma.ac.ir.
authors.forename: Mandana
authors.initials: M
authors.lastname: Amiri
authors.affiliation: Department of Chemistry, Payame Noor University, Ardabil, Iran.
authors.forename: Hamideh
authors.initials: H
authors.lastname: Imanzadeh
authors.affiliation: Department of Chemistry, Payame Noor University, Ardabil, Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Banaei
mesh_terms: D001205:Ascorbic Acid / Q000737:chemistry* / Q000652:urine*; D002244:Carbon / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods; D004566:Electrodes; D006801:Humans; D053758:Nanoparticles / Q000737:chemistry*; D010084:Oxidation-Reduction; D016062:Porosity; D012680:Sensitivity and Specificity; D013607:Tablets / Q000737:chemistry; D014527:Uric Acid / Q000737:chemistry* / Q000652:urine*
chemical_list: D013607:Tablets; D014527:Uric Acid; D002244:Carbon; D001205:Ascorbic Acid
keywords: Ascorbic acid; Tosyl functionalized carbon nanoparticles; Uric acid; Voltammetric sensor