Ruthenium-Based Electrode Modified by Gold Particles as Voltammetric Sensor for Non-Enzymatic Epinephrine Detection

A simple and efficient technique for voltammetric enzymeless detection of epinephrine (EP) is proposed. The technique applies hierarchical Ru-based electrodes modified by Au nano- to micro-sized particles, which were produced with laser-assisted synthesis. The cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were employed to characterize electrochemical properties of the electrodes. For EP detection, we obtained two DPV calibration curves that are linear in the range of 0.01-5 μM and 5-500 μM. The highest sensitivity (46.9 μA μM−1 cm−2) and the lowest detection limit (6.1 nM) are observed for the first linear range, whereas the estimated sensitivity and limit of detection for the second linear range are 2.1 μA μM−1 cm−2 and 17.8 nM, respectively. We also demonstrated that the proposed technique can be used for selective EP determination in the presence of such common interfering analytes as ascorbic acid and dopamine. The results of this study can be employed for development of low-cost voltammetric sensor platforms for non-enzymatic epinephrine detection in a physiological environment.