Ionic liquid/single-walled carbon nanotubes composite film modified carbon-ceramic electrode as an electrochemical sensor for the simultaneous determination of epinephrine and uric acid

In the present work, a carbon-ceramic electrode (CCE) modified by a composite of an ionic liquid and single-walled carbon nanotubes (IL-SWCNT/CCE) was prepared for the electrochemical determination of epinephrine (EP) in the presence of uric acid (UA). The morphology and surface characteristics of the prepared modified CCE were studied using scanning electron microscopy (SEM). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used for electrochemical studies and determinations. Their results showed that the IL-SWCNT/CCE has high electrocatalytic activity toward the oxidation of EP. The electrochemical behavior of EP is closely dependent on the pH; in basic media, its oxidation process is irreversible and there is no cathodic peak in reverse scan, while in acidic media the electrochemical behavior of EP becomes reversible. DPV measurements showed that the oxidation peak current was linear in the concentration range 1.0 x 10(-7) to 2.0 x 10(-4) M, and the detection limit was 2.8 x 10(-8) M. Also, it was confirmed that the IL-SWCNT/CCE can be used for the simultaneous measurement of EP and UA. The obtained results indicate that the IL-SWCNT/CCE has high stability, reproducibility, and repeatability. Finally, the developed electro-analytical method was successfully applied for the determination of EP in human serum and urine samples without any interference.