An ECL sensor for dopamine using reduced graphene oxide/multiwall carbon nanotubes/gold nanoparticles

An eletrochemiluminescence (ECL) sensor based on ECL of peroxydisulfate solution for detecting the dopamine (DA) was proposed using reduced graphene oxide/multiwall carbon nanotubes/gold nanoparticles (rGO/MWCNTs/AuNPs) hybrid modified glassy carbon electrode (GCE). The rGO/MWCNTs/AuNPs was synthesized by an effective and facile in situ chemical reaction using polyethyleneimine (PEI) as a reducing agent for both GO/MWCNTs and AuCl4−. The ECL behaviors of peroxydisulfate solution have been investigated at the rGO/MWCNTs/AuNPs/GCE, and DA was found to be able to enhance the ECL of peroxydisulfate solution. Under the optimized conditions, the enhanced ECL signal intensity of peroxydisulfate solution was linear with the concentration of DA in the range between 0.20 and 70 μM (R = 0.9902) with a detection limit (S/N = 3) of 0.067 μM. Furthermore, the developed sensor exhibited a high sensitivity, good reproducibility, stability for the detection of DA. The applicability of the proposed sensor was also evaluated by detecting DA in dopamine hydrochloride injection, human urine and serum.