Determination of norepinephrine using a glassy carbon electrode modified with graphene quantum dots and gold nanoparticles by square wave stripping voltammetry

In this work, a glassy carbon electrode modified with graphene quantum dots and gold nanoparticles (GCE/GQDs/AuNPs) was developed for norepinephrine (NE) determination using squarewave stripping voltammetry. GQDs were synthesized by citric acid pyrolysis and characterized by UV-Vis and fluorescence spectroscopy. The chemically synthesized AuNPs were characterized by transmission electron microscopy and UV-Vis spectroscopy (Plasmon Band). GCE/GQDs surface was characterized by Raman spectroscopy and scanning electron microscopy. The conditions for the determination of NE with GCE/GQDs/AuNPs were optimized. The linear range was observed between 0.5 and 7.5 mu molL(-1), with a detection limit (LOD) of 0.15 mu molL(-1). The proposed methodology was validated with spiked samples for good precision and accuracy. GCE/GQDs/AuNPs were used in pharmaceutical preparations (NE ampoules) and in rat brain tissue with satisfactory results. [GRAPHICS] .