A Sensor for Simultaneous Determination of Dopamine and Morphine in Biological Samples Using a Multi-Walled Carbon Nanotube/Chitosan Composite Modified Glassy Carbon Electrode

Abstract

A glassy carbon electrode modified with carbon nanotube/chitosan (MWCNTs-CHT/GCE) was used for the sensitive voltammetric determination of dopamine (DA) and morphine (MO). The electrochemical response characteristics of the modified electrode toward DA and MO were investigated by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and chronoamperometry (CA). Under optimum conditions the sensor provides a linear DPV response in the range of 1.0×10−6 to 2.1×10−4 M with a detection limit of 1.9×10−7 M for DA, and in the range of 2.0×10−6 to 1.0×10−4 M with a detection limit of 2.4×10−7 M for MO. The designed sensor was used successfully for the simultaneous determination of DA and MO in human blood serum and urine and satisfactory results were obtained.