High performance electrochemical sensors for dopamine and epinephrine using nanocrystalline carbon quantum dots obtained under controlled chronoamperometric conditions

This work describes a chronoamperometrically-controlled synthesis of nanocrystalline carbon quantum dots (C-dots) and their study based on UV-Vis, Raman, FTIR, fluorescence spectroscopy, atomic force and high resolution transmission electron microscopy. The electrochemical synthesis was carried out using 1-propanol as a carbon source and the C-dots properties exhibited a great dependence on the electrolysis time spent in the process. The C-dots were applied as prepared, on the surface of a glassy carbon electrode, showing excellent electrochemical response in the simultaneous determination of dopamine and epinephrine. The detection limits for the two analytes were 4.6 nmol L−1 and 6.1 nmol L−1, respectively, and the overall electrode performance exhibited a much better electrocatalytic response, in relation to the similar carbon modified electrodes prepared under comparable conditions, with single wall carbon nanotubes and graphene oxide.