Electrochemical Determination of Methamphetamine in Human Plasma on a Nanoceria Nanoparticle Decorated Reduced Graphene Oxide (rGO) Glassy Carbon Electrode (GCE)

Abstract

Methamphetamine is an addictive and illegal psychostimulant drug. Due to its simple synthesis, it is widely accessible and abused. Long-term consumption affects the user’s body. Hence, its determination is of great importance. Its oxidation on electrode surfaces is difficult and requires a suitable modifier. In this work, cerium oxide nanoparticles (nanoceria) decorated on reduced graphene oxide were utilized as the electrode modifier to improve the electrochemical response. Decoration of nanoceria in reduced graphene oxide enhances the stability of reduced graphene oxide on the electrode surface and avoiding π-π stacking and the formation of a graphite structure. In addition, the agglomeration of nanoceria decorated on the reduced graphene oxide is decreased. The optimum ratio of cerium oxide-reduced graphene oxide composite provided a synergistic catalytic effect upon the methamphetamine signal. An enhancement of the methamphetamine oxidation peak on the modified electrode at +0.9 V in Britton-Robinson buffer was observed by cyclic voltammetry at pH 10.0 in comparison with a bare electrode. Square wave voltammetry (SWV) was used for analysis. Under the optimized conditions, the linear dynamic range and limit of detection for the reported electrode were from 25.0 to 166.6 µM and 8.7 µM. The determination of methamphetamine in plasma indicated no significant matrix interferences.