Electrochemical Sensor Based on a Modified Graphite Screen Printed Electrode for Amitriptyline Determination

In this study, a graphene oxide (GO)/Fe 3 O 4 @SiO 2 nanocomposite was synthesized and used to modify a graphite screen printed electrode (GSPE) by drop casting, a simple and easy technique, in order to electrochemically detect amitriptyline. Electrooxidation of amitriptyline was studied on the GO/Fe 3 O 4 @SiO 2 /GSPE using cyclic voltammetry, linear sweep voltammetry, differential pulse voltammetry, and chronoamperometry. The oxidation peak potential of amitriptyline on the GO/Fe 3 O 4 @SiO 2 /GSPE appeared at 800 mV, which was accompanied with a lower overpotential and an increase in the oxidation peak current compared to that obtained on a bare GSPE. Under the optimized conditions, the method used in preparation showed a good dynamic concentration range from 2.0 to 1000.0 µM, with a limit of detection 0.5 µM. The modified electrode was successfully applied to amitriptyline determination in real samples.