Analytical Applications of Silica-Modified Electrodes -A Comprehensive Review

Abstract

This article aims to review the electroanalytical applications of chemically modified electrodes involving silica and silica-containing matrices. After a brief introduction to silica chemistry, the implication of pure and grafted silicas in electrochemistry, as well as that of the silica-based materials originating from the sol-gel technology, will be discussed. The interest of silica-modified electrodes (SiO 2 -MEs) with respect to electroanalysis will be pointed out by means of several examples. In the last five years, successful applications of SiO 2 -MEs have been achieved. Among them, silica grafted with inorganic films or organic moieties was successfully applied to the selective preconcentration or the electrocatalytic detection of various analytes. Also, the ability of the sol-gel chemistry to encapsulate enzymes within a silica matrix without preventing its activity was exploited in the development of new amperometric biosensors. These promising fields are thought to lead to significant advances in the near future, because of the explosive growth in both the synthesis of novel mesoporous organically-modified silica-based materials and the huge development of sol-gel chemistry in tailoring and construction of new modified electrodes.

Fast and simultaneous determination of Pb2+ and Cu2+ in water samples using a solid paraffin-based carbon paste electrode chemically modified with 2-aminothiazole-silica-gel

“…Walcarius presented very comprehensive reviews about the contributions of silica-based electrodes to electroanalysis. [19][20][21] Another advantageous feature presented by CPEs chemically modified with organofunctionalized silica is their high stability since chemical modifier is covalently bonded to silica which avoids its loss by dissolution or leaching.…”

“…Walcarius presented very comprehensive reviews about the contributions of silica-based electrodes to electroanalysis. [19][20][21] Another advantageous feature presented by CPEs chemically modified with organofunctionalized silica is their high stability since chemical modifier is covalently bonded to silica which avoids its loss by dissolution or leaching.Nanostructured [22][23][24] and mesoporous 25-30 silica have been widely used to prepare chemically modified electrodes for quantification of several metallic ions. Conventional silica (amorphous and silica gel) have also been used and it has allowed the reliable and low level quantification of Cu 2+ and Ni 2+ in ethanol fuel samples, [31][32][33] Hg 2+ and Cd 2+ in natural waters, 34,35 etc.…”

Peer Reviewed: Sol–Gels and Electrochemistry: Research at the Intersection.

“…This enzyme catalyzes the oxidation of glucose with oxygen to form gluconic acid and hydrogen peroxide. Electrochemical methods have been frequently used to monitor enzyme activity and quantify glucose in solution (7,33).…”

“…Sandwich, microfabricated, and screen-printable approaches have been demonstrated, as has the use of silica-polymer, silica-gold, and silica-carbon composite electrodes (18,22,23,(33)(34)(35)(36)(37). In the screen-printing approach, the "ink" is prepared by mixing graphite powder (or palladium-graphite powder), the enzyme, and a binder into a silica sol (37 ).…”

Cationic dyes immobilized on cellulose acetate surface modified with titanium dioxide: factorial design and an application as sensor for NADH

“…1 The most common materials that are usually employed as an inert support for the preparation of chemically modified electrodes (CME) are silica gel, silica prepared by the sol-gel process and zeolites. [2][3][4] Recently, the use of available alternative materials as cellulose and its derivatives as supports for preparation of electrochemical sensors has been increased. 5 The Cellulose acetate is a cellulose ester firstly synthesized in 1865 by P. Schutzenberger that has been widely marketed during the last two decades for their thermoplastic properties.…”