An electrochemical sensor for simultaneous determination of ascorbic acid, dopamine, uric acid and tryptophan based on MWNTs bridged mesocellular graphene foam nanocomposite

A multi-walled carbon nanotubes (MWNTs) bridged mesocellular graphene foam (MGF) nanocomposite (MWNTs/MGF) modified glassy carbon electrode was fabricated and successfully used for simultaneous determination of ascorbic acid (AA), dopamine (DA), uric acid (UA) and tryptophan (TRP). Comparing with pure MGF, MWNTs or MWNTs/GS (graphene sheets), MWNTs/MGF displayed higher catalytic activity and selectivity toward the oxidation of AA, DA, UA and TRP. Under the optimal conditions, MWCNs/MGF/GCE can simultaneously detect AA, DA, UA and TRP with high selectivity and sensitivity. The detection limits were 18.28 µmol L−1, 0.06 µmol L−1, 0.93 µmol L−1 and 0.87 µmol L−1, respectively. Moreover, the modified electrode exhibited excellent stability and reproducibility.