A New Approach for the Electrochemical Detection of Phenolic Compounds. Part I: Modification of Graphite Surface by Plasma Polymerization Technique and Characterization by Raman Spectroscopy

Abstract

This paper describes the early stages of preparation of an electrochemical sensor for the detection of phenolic compounds. For this aim, graphite leads were modified by plasma polymerization (PlzP) technique utilizing the monomer N-vinylpyrrolidone (VP) with its conductive property as precursor. The influence of different experimental parameters such as plasma discharge power and exposure time was investigated to optimize the proposed electrode. After the modification process, graphite leads (electrodes) were investigated by differential pulse voltammetry. The voltammograms were recorded between 0 and +1.0 V at 16 mVs−1. The surface characteristics of the PlzP-VP modified carbon lead surfaces were determined by Raman spectroscopy. It was clearly observed that VP monomer was polymerized to form polyvinylpyrrolidone that is a very well-known adsorbant for phenolics. As expected, it was clearly pointed out that the electrochemical conductivity of the modified carbon leads were varied due to adsorption of a model phenolic compound “gallic acid” at a certain concentration.