Study of Different Carbonaceous Materials as Modifiers of Screen-Printed Electrodes for Detection of Catecholamines

This paper describes the sensing properties of carbon-based screen-printed electrodes modified with three types of carbonaceous materials: 1) carbon nanotubes; 2) carbon microfibers; and 3) graphene. The electrochemical signals of screen-printed electrodes toward catechol derivatives were registered. It was demonstrated that the screen-printed electrodes modified with carbon nanofibers show the best performances in terms of kinetics, stability, and the smallest detection limit for all the catechol derivatives analyzed. Experimental conditions on the sensing performance of the screen-printed electrodes were investigated and optimized. The sensors displayed linear responses to catecholamines over concentration ranges from 1 mu M to 60 mu M with detection limits in the range of 0.84-3.52 mu M. An array of electrodes was constructed using the signals of three types of electrodes. Principal component analysis of voltammetric data shows that the array was able to discriminate among catechol derivatives. The sensors were successfully applied to determine trace amounts of catecholamines in plasma.