Abstract: In this work, a novel electrochemical sensor for epinephrine, which uses three dimensional molecularly imprinted polymer arrays (3-D MIP arrays) as the sensing materials, was reported for the first time. ZnO nanorods (ZNRs) were deposited on indium tin oxide coated polyethylene terephthalate (ITO/PET) film and used as high-surface 3-D scaffolds for 3-D MIP arrays deposition. The 3-D MIP arrays were prepared by electropolymerization of pyrrole onto ZNRs on ITO/PET film in the presence of epinephrine as template molecule. Due to the imprinted sites are located at the surface, as well as high specific surface area, these 3-D MIP arrays have good imprinted sites accessibility to template molecule. These 3-D MIP arrays are quite attractive for sensors, because each rod of arrays is accessible to analyte and can be used as sensing unit, thus yielding highly sensitive and efficient signal. 3-D MIP arrays based electrochemical sensor was characterized using scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV). Results indicated that this 3-D MIP arrays based electrochemical sensor exhibits high sensitivity and good selectivity for epinephrine. Under optimized conditions, the oxidation peak current of epinephrine showed two linear dynamic ranges (1-10 μM and 10-800 μM) using DPV method. Moreover, this electrochemical sensor has been successfully applied to the determination of epinephrine in epinephrine hydrochloride injections with satisfied recoveries (97.1% to 102.2%) and precision (2.2% to 4.5% of RSD)
Author keywords: Molecular imprinting polymers, Arrays, Electrochemical, Sensor, Epinephrine