A novel plastic-based graphite mesh electrode for spectroelectrochemical determination of drug substances in pharmaceutical preparations

Spectroelectrochemistry is an old field in analytical chemistry and yet a new one as well which not only can get the information about the electrochemical behavior of an analyte, but also its spectroscopic characteristics on the modified or even unmodified transparent working electrodes including mesh electrodes or semiconductor oxides like ITO or FTO [1]. It is new because of its potential ability to combine with chemometrics for analysis of the huge amounts of obtained data with intrinsic trilinearity [2]. Various types of transparent electrodes were used and it seems that the mesh electrodes consisting of carbon materials like graphite or carbon nanotubes due to their facile preparation and modification could best comply the requirements provided that the electrode substrate itself does not participate in electrochemical reaction otherwise there will be the risk of electrode deterioration. In some cases, this will necessitate the use of inert or even non-conductive substrates for electrode fabrication like paper or plastic-based devices [3, 4]. In this study a new plastic-based transparent carbon mesh electrode was fabricated using graphite as carbon source and after electrochemical activation was modified with graphene oxide or graphene quantum dots for further electron transfer enhancements. Spectroelectrochemical studies was performed using electrochemical techniques in combination with UV-Vis spectroscopy for analysis and determination of some drug compounds in biological samples and pharmaceutical preparations with standard addition method. The effective parameters including pH and potential scan rate were investigated and optimized. The obtained three-way data were analyzed with chemometrics techniques. The accuracy of method was further ascertained by recovery experiments.