Parisa Nasr-Esfahani, Ali A. Ensafi, and Behzad Rezaei

Abstract: In this work, a glassy carbon electrode (GCE) was modified with multiwall carbon nanotubes/ionic liquid/graphene quantum dots (MWCNTs/IL/GQDs) nanocomposite. Then, the nanocomposite was decorated with nickel-cobalt nanoparticles (NiCo NPs), and it was used as a non-enzymatic glucose sensor. Field emission scanning electron microscopy, X-ray diffraction spectroscopy,
and energy dispersive spectroscopy were employed to prove the electrodeposition of the NiCo NPs on the surface of MWCNTs/IL/GQDs/GCE. Also, cyclic voltammetric and amperometric methods were utilized for the investigation of the electrochemical behaviour of the NiCo NPs/MWCNTs/IL/GQDs/GCE for glucose oxidation. The novel amperometric sensor displayed two linear ranges from 1.0 to 190.0 mmolL1 and 190.0 to 4910 mmolL1 with a low detection limit of 0.3 mmolL1 as well as fast response time (2 s) and high stability. Also, the sensor showed good selectivity for glucose determination
in the presence of ascorbic acid, citric acid, dopamine, uric acid, fructose, and sucrose, as potential interference species. Finally, the performance of the proposed sensor was investigated for the glucose determination in real samples. NiCo NPs/MWCNTs/IL/GQDs/GCE showed good sensitivity and excellent selectivity.

Keywords: Multiwall carbon nanotubes · Ionic liquid · Graphene quantum dots · Nickel-cobalt nanoparticles · Glucose.