Voltammetric microsensor using PEDOT-modified gold electrode for the simultaneous assay of ascorbic and uric acids

Abstract

a b s t r a c tA voltammetric microsensor has been developed for the simultaneous assay of ascorbic (AA) and uric (UA) acids in aqueous solution. The electrode surface has been modified by means of electropolymerized conductive poly(3,4-ethylenedioxythiophene) PEDOT organic films. The electrocatalytic activity of the interface was dependent on the electropolymerization parameters inducing change in the structure and the morphology of the resulting polymer. The PEDOT thickness was optimized in order to maximize the peak potential separation between both acids oxidation to more than 400 mV. By using differential pulse voltammetry (DPV), the sensitivity of the microsensor was 0.87 lA lM À1 cm À2 and 4.05 lA lM À1 cm À2 for AA and UA respectively. The later was sensible to the presence of AA in the mixture, making evidence of the catalytic mechanism of UA regeneration. The calibration curves were linear in the concentration range 5.0-300 lmol L À1 for AA and 2.0-600 lmol L À1 for UA. The detection limits were 2.5 lmol L À1 and 1.5 lmol L À1 respectively. The sensor response was unmodified in the presence of the major electroactive biomarkers. The application of the PEDOT modified microsensor to the analysis of human blood serum was evaluated.

Control of adhesion using surface functionalisations for robotic microhandling

“…On the contrary, Ppy and Pedot induce lower pull-off forces on Si substrate (-25.0 nN and -15.0 nN, respectively) than on Au substrate (-62.0 nN and -86.1 nN, respectively). The most important difference, observed for Pedot films, can be easily explained by the strong affinity of sulfur atoms for gold substrates that has already been extensively studied and used, especially for the elaboration of Self-Assembled Monolayers [18], [19].…”

Effect of Ionic Liquids on the Physical Properties of the Newly Synthesized Conducting Polymer

“…Su and Cheng used the PEDOT-modified screen-printed electrode for the determination of cysteine [9]. Conducting polymer modification is a very good technique, but has limitations because of its low sensitivity [10]. Even though the sensitivity can be improved by the addition of nanomaterials such as Pd and gold nanoparticles, it still has some limitations [11][12][13].…”

Amperometric Determination of Ascorbic Acid on an Au Electrode Modified by a Composite Film of Poly(3,4-ethylenedioxythiophene) and Superconductive Carbon Black

“…20,21 The electrochemical determination of AA is generally based on its reducing properties, 22 but it is difficult to determine AA by its direct oxidation, because the oxidation potentials of AA, DA and UA are very similar on bare electrodes. [23][24][25] On the other hand, the direct oxidation of AA on bare electrodes is irreversible, which not only requires a high overpotential, but also suffers from a pronounced fouling effect on the surface, resulting in poor sensitivity and selectivity.…”