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.

A novel electrochemical sensor was constructed by employing zirconium based metal organic framework (NH2-UiO-66) and walnut derived carbon (WC) as modified materials for the highly sensitive and selective determination of paracetamol (Para) and para-aminophenol (PAP). Characterization results of the texture properties of the NH2-UiO-66/WC nanocomposite revealed that highly dispersive MOF particles were filled in large pores of WC to form homogeneous composite. The resulting composite modified electrode showed excellent electrocatalytic ability for the target molecules and good conductivity. Under optimal experimental conditions, the obtained NH2-UiO-66/WC electrode presented excellent analytical performances for Para and PAP detection with wide linear range (1-150 μM) and low detection limits (0.17 μM for Para and 0.32 μM for PAP). Finally, the proposed method was successfully used in determination of Para and PAP contents in River water and commercial tablets with satisfactory recoveries.

A simple, effective and rapid method for the electrochemical detection of morphine is described based on glassy carbon modified electrode with poly(CTAB). In this work, poly(CTAB) thin film was generated through elecropolymerization of the surfactant CTAB. The formation of nanoporous thin film of poly(CTAB) was confirmed by field emission scanning electron microscopy (FESEM) with energy dispersive spectra (EDS) and Fourier transform infrared spectroscopy (FTIR). The electrochemical behavior of morphine is explained in terms of the anodic oxidation of its tertiary amino group. The limit of detection was calculated as 0.2 μM with a good regression between concentration and peak current of morphine by using differential pulse voltammetry within the range of 50 nM to 20 μM. The poly(CTAB)/GCE based sensor shows excellent electrochemical performance for the detection of morphine and this sensing platform can be effective for the detection of similar molecules.