An enzyme-free electrochemical glucose sensor: Directly electrosynthesized nickel nanoparticles/graphene oxide composite on a platinum microelectrode

Using a simple and efficient electrochemical method, nickel nanoparticles (NiNPs) were directly fabricated on graphene oxide (GO) layers to modify platinum microelectrodes (Pt/GO@NiNPs). With the fabricated Pt/GO@NiNPs microelectrodes, glucose was electro-oxidized directly in an alkaline environment without the presence of enzymes. The enzyme-free electrochemical glucose sensor based on Pt/GO@NiNPs microelectrode has exhibited many advantages such as a high sensitivity of 1091 μA mM⁻¹ cm⁻², a good repeatability, a wide linear range from 0.05 mM to 20.00 mM and a low detection limit of 18 μM. In the presence of interferers such as ascorbic acid, lactose, urea and dopamine, the Pt/GO@NiNPs microelectrode has performed stably and has been less affected, showing a high selectivity. The developed Pt/GO@NiNPs electrochemical sensor has been used to detect glucose in a 5 % glucose intravenous infusion with an error of only 0.27 % compared to the value stated on the bottle label. The Pt/GO@NiNPs sensor has also been used to accurately quantify glucose content in a diabetic patient’s urine sample.