An electrochemical sensor based on reduced graphene oxide/β-cyclodextrin/multiwall carbon nanotubes/polyoxometalate tetracomponent hybrid: Simultaneous determination of ascorbic acid, dopamine and uric acid

In this work, a novel tetracomponent hybrid electrochemical sensor was constructed with reduced graphene oxide/beta-cyclodextrin/multiwall carbon nanotubes/polyoxometalate (RGO-CD-MWCNT-POM), which achieved simultaneous detection of ascorbic acid (AA), dopamine (DA) and uric acid (UA). First, the RGO-CD-MWCNT-POM was synthesized by assembly of graphene oxide (GO), beta-cyclodextrin (CD), and multiwall carbon nano tube (MWCNT), with subsequent reduction of GO in the assistance of polyoxometalate (POM). Afterward, the morphology and structural properties were characterized by transmission electron microscope (TEM), energy dispersive X-ray mapping (EDS), scanning electron microscope (SEM), Raman spectroscopy, and thermogravimetric analysis (TGA). After its modification on glassy carbon electrode (GCE), RGO-CD-MWCNT-POM could simultaneously detect AA, DA, and UA by voltammetry method. Its enhanced electrochemical sensing performances derive from the combined merits of each component: supramolecular recognition from CD, excellent electronic properties from carbon components, and electrocatalyst from POM. Under optimal conditions, the linear ranges of AA, DA and UA were 5-2000, 0.5-300 and 1-400 mu M with the detection limits with 0.84 mu M, 0.04 mu M, 0.05 mu M, respectively. The proposed sensor was also well applied in practical simultaneous measurement in urine sample with the recovery ranges of 94%similar to 108%. Our work suggests the fabricated sensor is promising for constructing excellent sensing platform.