Well-dispersed poly(cysteine)-Ni(OH)2 nanocomposites on graphene-modified electrode surface for highly sensitive non-enzymatic glucose detection

Abstract

A kind of nickel-based nanomaterial was prepared and its application in the highly sensitive non-enzymatic glucose detection was realized in this article. Cyclic voltammetric scan generated the well-dispersed poly(cysteine)-Ni(OH)2 nanocomposites, which were analyzed by scanning electron microscopy, infrared spectroscopy and X-ray photoelectron spectroscopy, on the grephene-modified electrode surface. In strong alkaline medium, this Ni-based nanomaterial showed a good electrocatalytic activity for the oxidation of glucose. The current change during the chronoamperometric measurement showed a linear dependence on the glucose level from 1.0 μM to 0.10 mM and that from 0.20 mM to 2.0 mM, with a detection limit of 0.35 μM and a sensitivity of 1092 μA mM−1 cm-2. The fast response time, good selectivity, satisfactory reproducibility, excellent repeatability, high stability and the successful application in the determination of blood glucose demonstrated the excellent performance of the fabricated sensor. The analysis on cell lysate reveals the high-glucose medium could induce the enhancement of glucose content in human umbilical vein endothelial cells and this glucose accumulation in these cells was one of important reasons for the cell injury.