New Insight into the EC’ Mechanism of Uric Acid Regeneration in the Presence of Ascorbic Acid on a Poly(3,4‐ethylenedioxithiophene) Modified Gold Electrode

Abstract

A gold electrode surface was functionalized by means of an electropolymerized conductive poly(3,4‐ethylenedioxythiophene) (PEDOT) organic layer. This modified electrode was used for the electrochemical detection of ascorbic (AA) and uric (UA) acids in an aqueous mixture with a selectivity around 340 mV. The electrochemical reactions kinetics were limited by AA diffusion and UA adsorption at the electrode surface, respectively. Following a previous study ([Electrochem Comm. 2011, 13, 423–425]) cyclic voltammetry was used to provide a better understanding of the EC’ mechanism of regeneration of UA by AA. Experiments particularly showed that allantoin (i. e. the final product of UA oxidation) is not actually involved in the synergic mechanism but rather the oxidized UA product diimine which is adsorbed at the electrode surface.

La(OH)3 Multi-Walled Carbon Nanotube/Carbon Paste-Based Sensing Approach for the Detection of Uric Acid—A Product of Environmentally Stressed Cells

“…Furthermore, peak resolution is fairly good on lower pH values, ending with pH 6 where the peak is well defined and narrow, unlike the broad peaks at higher pH. The obtained results correlate well with UA’s pKa [ 55 ] values and electrocatalytic oxidation mechanism ( Scheme 2 ) [ 55 ].…”

Electrocatalytic Determination of Uric Acid with the Poly(Tartrazine)-Modified Pencil Graphite Electrode in Human Serum and Artificial Urine

“…The DPV results and calibration curves of electrochemical UA oxidation are shown in Figure . With the oxidation of the unsaturated carbon bond in the middle of the purine ring, UA-4,5-diol is formed, and the peak height increases commensurately with UA . The significant analytical parameters including LOD and linear ranges for UA detection are 0.10 μM [i.e., from the blank signal, LOD = 3 s / m , where s is the standard deviation of the blank solutions ( n = 6) and m is the slope of the calibration curve], 0.34–60, and 70–140 μM, respectively.…”

Development of Methanol Sensor Based on Sol-Gel Drop-Coating Co3O4·CdO·ZnO Nanoparticles Modified Gold-Coated µ-Chip by Electro-Oxidation Process

“…The low dimensions of the CCZ nanoparticles also enhance the interactions between the CCZ nanoparticles and MeOH molecules. Thus, when the MeOH molecule comes into contact with the CCZ/Au/μ-Chip surface, it loses one electron to the conduction band of the CCZ nanoparticles, and thus oxidize to methanoic acid, as presented in [ 49 , 50 , 51 ]. The CCZ/Au/μ-Chip electrode provides improved I-V responses compared to the Au/μ-Chip, indicating that the CCZ nanoparticles amplify the current responses during MeOH sensing.…”