Assembly of graphene and nickel nanoparticles on anion exchange resin microspheres for the amperometric detection of carbohydrates in combination with capillary electrophoresis

• Graphene and nickel nanoparticles were coated on anion exchange resin microspheres.
• The prepared microspheres were embedded in pipette tips to form electrodes.
• The electrodes exhibited high electrocatalytic activity toward carbohydrates.
• The electrodes were applied in the detection of capillary electrophoresis.

Graphene and nickel nanoparticles (NiNPs) were assembled on anion exchange resin (AER) microspheres based on the electrostatic interaction between graphene oxide sheets and AER and the subsequent chemical reduction. The prepared AER@graphene–NiNP composite core–shell microspheres were characterized by scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. Moreover, they were embedded in the bores of pipette tips to fabricate electrodes. The performance of the novel electrodes was demonstrated by measuring sucrose, glucose and fructose in combination with capillary electrophoresis. The three analytes were well separated within 8 min in a 40 cm long capillary at a separation voltage of 12 kV. The graphene–NiNP composite microsphere electrodes exhibited higher sensitivity (213.578–317.064 nA mM−1), lower detection limits (0.75–1.05 μM) and enhanced separation efficiency in the detection of these carbohydrates. The advantages of the electrodes include ease of fabrication, low cost and pronounced electrocatalytic activity toward carbohydrates, indicating great promise for a wide range of applications.