Voltammetric Determination of Epinephrine in Pharmaceutical Sample with a Tyrosinase Nanobiosensor

A novel carbon paste electrode modified with a multiwalled carbon nanotube (MWCNT), tyrosinase, and Nafion membrane (CP/MWCNT/Tyr/Nafion) was developed for voltammetric determination of epinephrine (EP). The CP/MWCNT/Tyr/Nafion biosensor exhibited linear dynamic range from 5.0 x 10(-6) M to 5.0 x 10(-4) MEP concentration with a good correlation coefficient (R-2 = 0.9985). The detection limit of the biosensor was calculated as 3.0 x 10(-7) MEP from the signal-to-noise ratio (S/N = 3). Reproducibility of the biosensor was also calculated from relative standard deviation as 3.8% (n=5). Ascorbic acid (AA) and uric acid (UA) did not interfere in the quantification of epinephrine. The developed biosensor was also successfully applied for the determination of epinephrine in pharmaceutical sample. The CP/MWCNT/Tyr/Nafion biosensor has good sensitivity, selectivity, stability, easy preparation procedure, and short analysis time and can be used for the determination of EP in pharmacological samples.