Introduction:
In this study, solar exfoliated graphite oxide modified glassy carbon electrode
was used for the anodic oxidation of epinephrine in a phosphate buffer medium at pH7. The
modified electrode showed fast response and sensitivity towards Epinephrine Molecule (EP). The
electrode was characterized electrochemically through Cyclic Voltammetry (CV) and Differential
Pulse Voltammetry (DPV). Area of the electrode enhanced three times during modification and studies
reveal that the oxidation process of EP occurs by an adsorption controlled process involving two
electrons. The results showed a detection limit of 0.50 ± 0.01μM with a linear range up to 100 μM.
The rate constant calculated for the electron transfer reaction is 1.35 s-1. The electrode was effective
for simultaneous detection of EP in the presence of Ascorbic Acid (AA) and Uric Acid (UA) with
well-resolved signals. The sensitivity, selectivity and stability of the sensor were also confirmed.
Methods:
Glassy carbon electrode modified by reduced graphene oxide was used for the detection
and quantification of epinephrine using cyclic voltammetry and differential pulse voltammetry.
Results:
The results showed an enhancement in the electrocatalytic oxidation of epinephrine due to
the increase in the effective surface area of the modified electrode. The anodic transfer coefficient,
detection limit and electron transfer rate constant of the reaction were also calculated.
Conclusion:
The paper reports the determination of epinephrine using reduced graphene oxide modified
glassy carbon electrode through CV and DPV. The sensor exhibited excellent reproducibility
and repeatability for the detection of epinephrine and also its simultaneous detection of ascorbic acid
and uric acid, which coexist in the biological system.
Graphene Nanocomposite Modified Glassy Carbon Electrode: As a Sensing Platform for Simultaneous Determination of Methyldopa and Uric Acid
