Electrochemical Detection of Epinephrine Using an L-Glutamic Acid Functionalized Graphene Modified Electrode

Abstract

The development and application of an L-glutamic acid functionalized graphene nanocomposite, modified glassy carbon electrode are reported for the determination of epinephrine. The properties of the nanocomposite were characterized by scanning electron microscopy, ultraviolet-visible absorption spectroscopy, infrared spectroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. The modified electrode had high sensitivity and strongly catalytic activity for the detection of epinephrine. A linear relationship between the epinephrine concentration and the current response was obtained in the range of 1 × 10⁻⁷ M to 1 × 10⁻³ M by differential pulse voltammetry with a limit of detection of 3 × 10⁻⁸ M. The modified electrode was employed to determine epinephrine in urine with satisfactory results.

Keywords:

• Electrochemical sensor
• Epinephrine
• Graphene
• L-glutamic acid
• Nanocomposite

Notes

Note: NR, not reported; DPD, 2-(2,3-dihydroxy phenyl)-1,3-dithiane; GME, graphene-modified electrode; GR, graphene; AuNPs, gold nanoparticles; MPA, Mercaptopropionic acid; CA, cystamine; PLG-Ag/GCE, a silver-doped poly(L-glutamic acid) modified electrode.

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