Electrochemical Sensing of Epinephrine on a Carbon Nanofibers and Gold Nanoparticle-Modified Electrode

Carbon nanofiber-gold nanoparticle electrochemical sensor was fabricated by drop-coating carbon nanofiber followed by electrodeposition of gold nanoparticles on a glassy carbon electrode (GCE), for the detection of epinephrine (EP). The acid-activated carbon nanofibers were characterised by Fourier transform infrared spectroscopy. Field emission scanning electron microscopy and transmission electron microscopy were used to study the morphological and structural properties of the nanomaterials. Cyclic voltammetry, electrochemical impedance spectroscopy (EIS), and square wave voltammetry were used for electrochemical characterisation of the electrodes in each step of the construction of the electrochemical sensor. When compared to the bare GCE, the modified electrode had enhanced electrocatalytic effect. Square wave voltammetry was used for the quantitative determination of epinephrine. A well-defined anodic peak potential for epinephrine was observed at pH 6 in 0.1 M phosphate buffered solution (PBS). The sensor was linear within epinephrine concentration range of 50 µM to 1 mM with a detection limit of 1.70 µM. Graphical abstract