Selective determination of epinephrine in the presence of ascorbic acid using a glassy carbon electrode modified with graphene.
A graphene-modified glassy carbon electrode was fabricated via a drop-casting method, and applied to the electrochemical detection of epinephrine. The capacity of the graphene-modified glassy carbon electrode for the selective detection of epinephrine was confirmed in a sufficient amount of ascorbic acid (2 mmol L(-1)) by cyclic voltammetry. The modified electrode showed an excellent electrocatalytical effect on the oxidation of epinephrine. A pair of well-defined redox waves were observed in voltammograms of epinephrine in a phosphate buffered solution (pH 4.0). The peak potentials of epinephrine remained unchanged, and the oxidation peak currents showed a linear relation versus the epinephrine concentration in the range of 3.85 × 10(-7) - 1.31 × 10(-5) mol L(-1) and 1.31 × 10(-5) - 1.09 × 10(-4) mol L(-1) with a correlation coefficient as follows: i(pa1) = -4.25 × 10(-6) - 1.99c (mol L(-1)), R(1) = 0.9953; i(pa2) = -4.31 × 10(-5) - 0.315c (mol L(-1)), R(2) = 0.9988. Detection limit is estimated to be 8.9 × 10(-8) mol L(-1). Graphene-modified glassy carbon electrode was applied to epinephrine sample analysis, and the results were in good agreement with the standard values.
Department of Chemistry and Chemical Engineering, Heze University, Daxue Road, Heze, Shandong 274015, PR China.
Xia
X
Li
Meifeng
M
Chen
Xinying
X
Ma
D001205:Ascorbic Acid / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D004837:Epinephrine / Q000032:analysis* / Q000737:chemistry; D005898:Glass / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection
D006108:Graphite; D001205:Ascorbic Acid; D004837:Epinephrine