Zeolite-modified electrodes with analytical applications*

Pure and Applied Chemistry (Impact Factor: 2.49). 02/2011; 83(2):325-343. DOI: 10.1351/PAC-CON-10-07-08


Zeolite-modified electrodes (ZMEs) have been widely investigated because of their chemical, physical, and structural characteristics (shape, size, and charge selectivities; physical and chemical stabilities; high ion-exchange capacity; hydrophilic character; etc.), which make them of high interest in the design of electroanalytical systems. The paper presents recent literature data about fundamental and practical aspects related to the obtaining and applications of ZMEs. Some new ZMEs based on carbon paste incorporating soluble phenothiazinic dyes adsorbed on X-type zeolites are assessed comparatively, and the influence of some experimental parameters on the electrochemical response of these electrodes was investigated. The kinetic parameters for the heterogeneous electron-transfer process corresponding to the surface-immobilized mediators were determined, and all observed differences were used as evidence of the influence of the mediator structure and of the zeolite nature on the electrochemical activity of the new electrodes and on their electrocatalytic properties toward beta-nicotinamide adenine dinucleotide (NADH) or ascorbic acid (AA) electro-oxidation and H2O2 electroreduction.

Download full-text


Available from: Liana Maria Muresan, Oct 06, 2015
184 Reads
  • Source
    • "Structuration of electrode surfaces with inorganic thin films has become a well-established field of interest, notably for applications in electroanalysis [1–21]. Various materials have been used for that purpose, including zeolites [2] [3] [4] [5], clays [6] [7] [8] [9] and layered double hydroxides [10] [11], silica [3] [12] [13] and silica-based organic–inorganic hybrids [13] [14], sol–gel materials [14] [15] [16] [17] and, more recently, ordered mesoporous materials [3,18–21]. The driving force to select one or another of these electrode modifiers often relies on the particular properties (ion exchange, selective recognition, hosting capacity, size selectivity, redox activity, permselectivity, etc.) which can be useful to the final application (preconcentration electroanalysis, electrocatalysis, permselective coatings, biosensors, . . "
    [Show abstract] [Hide abstract]
    ABSTRACT: This work describes the electro-assisted generation of clay-mesoporous silica composite films onto glassy carbon electrodes (GCEs). The method involved the deposition of clay particles by spin-coating on GCE and the subsequent growing of a surfactant-templated silica matrix around these particles by electro-assisted self-assembly (EASA). EASA typically consisted in applying a cathodic potential to the electrode immersed into a hydrolyzed sol (containing tetraethoxysilane, TEOS, as the silica source, and cetyltrimethylammonium bromide, CTAB, as surfactant) in order to generate the necessary hydroxyl catalysts inducing the formation of the mesoporous silica. In such conditions, alongside the silica deposition process, the inter-layer distance between the clay sheets was found to increase as a result of CTAB ion exchange. After removal of the surfactant template, the composite film became highly porous (i.e., to redox probes) and the clay recovered its pristine interlayer distance and cation exchange properties. This made it promising for application in preconcentration electroanalysis, as pointed out here using copper(II) as a model analyte, especially because it offered much better long-term operational stability than the conventional (i.e., without silica binder) clay film electrode.
    Electrochimica Acta 12/2013; 112:333-341. DOI:10.1016/j.electacta.2013.08.119 · 4.50 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The preparation and properties of a simple and cost-effective gold-coated coir fibre electrode are reported. The natural fibre (Young’s modulus (Y) = 65.10 MPa), without any pre-treatment, was sputter coated with gold to a thickness of 125 nm. The flexible and mechanically strong (Y = 83.84 MPa) composite fibre with electrical resistivity 4.4 × 10-4 cm, behaved normally as an electrode in well understood electrochemical processes such as cyclic voltammetry and electro-polymerization. The electrode was evaluated both in aqueous and non-aqueous media. The results were comparable with the control data generated using a conventional gold wire electrode.
    ACS Sustainable Chemistry & Engineering 12/2013; DOI:10.1021/sc400389u · 4.64 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: N,N'-bis[(E)-(1-pyridyl) methylidene]-1,3-propanediamine (PMPDA) self-assembled monolayer (SAM) was covalently prepared on a glassy carbon electrode (GCE). The electrode surface modification was characterized by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) techniques. Then GC-PMPDA SAM modified electrode was used to investigate the electrochemical behavior of hydroxychloroquine (HQ) using CV, double potential step chronocoulometry and linear sweep voltammetry (LSV) techniques. Using these techniques, the diffusion coefficient (D), electron transfer coefficient (α) and exchanging current density (j0) for HQ were calculated. Furthermore the modified electrode was applied as a high sensitive biosensor for determination of HQ in the presence of acetaminophen (AC). The GC-PMPDA SAM modified electrode provides two linear responses for HQ in the presence of AC in the concentration ranges from 0.09 to 10.21μM and 10.21 to 98.29μM by differential pulse voltammetry (DPV). The detection limit (three times the signal blank/slope) was 4.65nM. Finally the modified electrode was satisfactorily used for determining of HQ in human body fluids. Copyright © 2014 Elsevier B.V. All rights reserved.
    Colloids and surfaces B: Biointerfaces 10/2014; 123. DOI:10.1016/j.colsurfb.2014.10.002 · 4.15 Impact Factor
Show more