The carbon-based electrodes used for electrochemical analyses are widely known to have a wide range of potential, easy rechargeability, and chemical inertness. They are also inexpensive, biocompatible and easy to fabricate [1]. It is however difficult to add functional groups on their surfaces because of the limited reactivity of the electrolyte. In order to improve their chemical stability and increase their sensitivity, a new electrode paste material is required.
For example, nanostructured material carbons combine mechanical and electric properties that are ideal for electrochemical applications. Graphene offers a combination of high conductivity and a huge surface area. This makes it ideally suited for such synthesis. Recent technological advances allow the large scale synthesis of controlled and uniformly dispersed nanostructures with various functional groups. It is possible to characterize their chemical and electrical properties using various techniques including scanning electron microscope (SEM).
The electrode can also be improved by replacing the traditional supporting material with a less expensive carbon based substance such as petroleum coke, coal tar or pitch. This substitution reduces the cost and increases the sensitivity and selection of the electrode. The electrode can be more stable in an environment that is harsh like the steel industry. The Soderberg paste electrode market is predicted to grow due to these benefits.
An important application for an electrode is the determination of toxic substances in food products. For this, a voltammetric method is usually employed. The square-wave technique (SWV) is particularly simple and reliable. With its high sensitivity, it is possible to identify even very low concentrations. Based on the fact an electrical current is created when a substance oxidizes or reduces at the electrode surface, the SWV works. The current generated is proportional with the concentration of the substance.
Several electrochemical analyses have been performed to determine the presence of toxic tartrazine in aqueous solution. These include cyclic voltammetry, Electrochemical Impedance Spectroscopy and cyclic voltammetry. In the present study, an electrode made of poly(niacin), which was modified to look like carbon paste, was fabricated in order to test for TZ content. The PNMCPE as well as the bare-carbon paste electrode were studied in detail using cyclic voltammetry, Field emission scanning electro microscopy and FE-SEM.
Both the PNMCPE (and BCPE) showed high sensitivity in the detection of TZ. SWV-based results revealed that peak current linearly correlated with TZ. The slope is close to 0.5 and this indicates a reaction that's controlled by diffusion of depolarizer. The PNMCPE electrode was much more sensitive than the bare carbon paste. This was mostly due to the electrode being modified with niacin. PNMCPE is also capable of determining TZ levels in a commercial colouring powder.
English
Write a Message