Graphene Nanosheets Functionalized With Nile Blue as a Stable Support for the Oxidation of Glucose and Reduction of Oxygen Based on Redox Replacement of Pd-Nanoparticles via Nickel Oxide, Ali A. Ensafi, Zeinab Ahmadi, MehdElectrochim. Acta, 2015, 173, 619
A novel, cheap and simple enzymeless glucose sensor is introduced based on Pd/NiO nanoparticles
decorated on Nile blue functionalized reduced graphene oxide (rGO). First, NiO was decorated on rGO
and/or Nile blue functionalized rGO. Then, they were converted to bimetallic system by replacement of
NiO with Pd nanoparticles, (Pd/NiO@rGO and Pd/NiO@Nile–rGO) to prepare the modified carbon paste
electrodes (CPE). Pd/NiO@Nile–rGO was prepared using functionalized graphene oxide with Nile blue
through diazonium reaction and deposition of Pd–NiO nanoparticles with chemical reaction. The
nanocomposites structure were characterized by spectroscopic and electrochemical methods.
Electrochemical studies showed that Pd/NiO@Nile–rGO has higher electrocatalytic activities toward
glucose oxidation compare to Pd/NiO@rGO nanoparticles. Potential cycling test was employed to confirm
the high sensitivity and stability of Pd/NiO@Nile–rGO compare to Pd/NiO@rGO. Then, a sensitive
amperometric detection of glucose is achieved at –0.040 V (vs. Ag/AgCl) with a low detection limit of
2.2 mmol L–1 and with a wide linear range of 0.020–20.0 mmol L–1 glucose using Pd/NiO@Nile–rGO/GCE.
Five different Pd/NiO@Nile–rGO/CPEs were tested separately for the amperometric response of glucose,
providing a relative standard deviation of 4.8%.
The selectivity of the modified electrode was studied too. The applicability of Pd/NiO@Nile–rGO/CPE
was investigated by determining glucose in blood serum samples with satisfactory results. In the second
part of this work the electrocatalytic activity of the modified electrodes for the electro-reduction of
oxygen have been studied too. The results of our studied confirmed that Pd/NiO@Nile–rGO
nanocomposites act as an electrocatalyst for the oxidation of glucose and reduction of oxygen, beside
them. Thus, the nanocomposite is a good candidate for glucose fuel cell.