A General Approach Based on Sampled‐Current Voltammetry for Minimizing Electrode Fouling in Electroanalytical Detection

Abstract

Electrochemical analysis of species known to passivate electrode surfaces remains challenging. We previously proposed a new method, dealing with sampled-current voltammetry performed on an electrode array to mimic polarography at a dropping mercury electrode for the detection of copper. In this work, we study the effectiveness of this method to circumvent electrode fouling with the analysis of phenol solutions at high concentrations (10 À2 mol L À1 ), known to polymerize on electrode surface during its oxidation. Electrode arrays well-adapted to the analysis with such system are prepared by photolithography and characterized by X-ray photoelectron spectroscopy, X-ray diffraction, and voltammetry. Although analyses performed in conventional linear voltammetry or sampled-current voltammetry on a single electrode are considerably affected by electrode fouling, a linear calibration plot was achievable using our method. Modeling of the electrochemical signal showed that the current depends only on the applied potential and a parameter characteristic of the passivation phenomenon. It also underlined that sampled-current voltammetry on an electrode array can circumvent the problem of passivation by a judicious choice of the sampling time.

Coupling of Anodic Stripping Voltammetry with Sampled-Current Voltammetry on an Electrode Array: Application to Lead Detection

“…The electrodes prepared by photolithography [22,24] were cleaned in acetone with slow stirring (50 rpm) for 5 min and rinsed with ultra-pure water. After drying under vacuum, the electrode array was treated for 25 min with UV/ozone.…”

“…(2) An electrode array (∅ = 0.5 mm) made with photolithography process [22]. All the electrochemical experiments were performed at room temperature (25 • C) under deaerated conditions in an electrochemical cell adapted to the electrode (for a classical single electrode the cell contains 20 mL of liquid)…”

“…Concerning the homemade electrode array the electrochemical experiments were performed in a homemade electrochemical cell ( Figure 1) [22]. The first piece in metal supports the electrode array platform and a second one made of glass contains 22 sprung gold plated pins, which assure electrical contacts and a 15 mm diameter tank for the reception of liquids and electrodes.…”

“…We have previously reported a new analytical method called Electrodes Array for Sampled-Current Voltammetry (EASCV) based on sampled-current voltammetry performed on an electrode array [22,23]. A potential was applied independently on each electrode of the array and the resulting current was read at a short sampling time.…”

Indirect Electrochemical Detection of NADH Through an Active Stainless Steel Fiber Felt (SSFF) Electrode Decorated With the Amino‐Graphene/Nafion Nano Composite Films

“…Even so, the high over potential encountered as directly oxidizing NADH molecules, which may cause serious surface fouling on the working electrode, is one of the primary barriers for electrochemical methods. In order to overcome this problem, not only the advanced materials capable of decreasing the oxidation potential of NADH, but also the novel indirect electrochemical detection techniques based on redox mediators have been designed to facilitate the NADH electrochemical measurement.…”