Epinephrine Electrochemical Sensor Bsed on L-Mthionine Film/ZnO Nanoparticles in Carbon Paste Electrode

One example of neurotransmitters considered is epinephrine (EP), also known as adrenaline. EP as a neurotransmitter is synthesized biologically in the adrenal medulla and sympathetic nerve terminals. It has a key role in the functioning of central nervous system (CNS), renal, hormonal, and cardiovascular system [1]. Numerous diseases are related to the concentration of EP, such as Parkinson’s disease, Alzheimer’s disease, hypertension and multiple sclerosis [2]. Furthermore, EP is used as a drug to treat bronchial asthma, organic heart disease, anaphylaxis, anaphylactic shock and superficial bleeding. Several methods have been reported for EP analysis [3] and due to electro active nature of EP, it can also be determined electrochemically. Therefore, it is necessary to effectively enhance the sensitivity of electrochemical sensors for medical applications. This paper demonstrates a new modified carbon paste electrode fabricated from l-methionine film /ZnO NPs, by cyclic voltammetry that the whole procedures take only several minutes and can be used for quantification of EP in different real samples. Combination of the benefits of both polymer/ZnO NPs and CPE, enhanced the electrocatalytic activity and voltammetric performance of the fabricated sensor for the oxidation of EP. The surface and electrochemical characterization of the modified electrode was investigated by field emission scanning electron microscopy (FESEM), chronocoulometry (CC), cyclic voltammetry (CV) and differential pulse voltammetry (DPV). In the optimized conditions, the presented sensor is able to detect the concentration range of 0.5–12.4 μM with a limit of detection of 40 nM. The presented methodology possesses a reliable reproducibility, repeatability and stability in biological samples. These results proved that the composite has a hopeful capacity in electrochemical sensors development. The developed electrochemical sensor was successfully employed for the determination of analytes in real samples with satisfactory results.