Non-enzymatic sensor based on nitrogen-doped graphene modified with Pd nano-particles and NiAl layered double hydroxide for glucose determination in blood

Abstract

Herein, a novel highly sensitive and selective non-enzymatic glucose sensor was developed. This sensor was prepared with a one-step electrodeposition process, which means that the palladium nanoparticles and NiAl layered double hydroxide were electrosynthesized simultaneously (Pd-NiAl-LDH) on a graphite sheet electrode (GS) covered by nitrogen-doped functionalized graphene (NFG). The sensing performance was investigated by linear sweep voltammetry (LSV), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and chronoamperometry (CA) techniques. The results revealed that the one-step electrodeposition of Pd-NiAl-LDH nanocomposite on NFG provided a large surface area containing Ni and Pd electroactive centers and enhanced the electron transfer. This resulted in a remarkable effect on signal amplification toward glucose oxidation, with a wide linear range from 500 nM to 10 mM, an acceptable sensitivity of 315.46 μA. cm−2. dec−1 and a low detection limit of 234 nM based on a signal to noise ratio of 3. The relative standard deviation (RSD%) in all detection tests was lower than 5% and also the performance of fabricated GS/NFG/Pd-NiAl-LDH electrode which investigated in human real samples including serum, plasma and blood was acceptable, indicating the ability of the fabricated sensor in biological and clinical applications.