Crumpled graphene/Ni(OH)2 nanocomposites applied as electrochemical sensors for glucose and persistent contaminants

Abstract

Different Ni depositions on acetate were performed using adsorption and electrochemical deposition methods. The optimization of the Ni deposition was carried out taking into account the best electrocatalytic behavior for glucose oxidation in an alkaline medium employing chronoamperometry. The best electrochemical behavior was achieved using electrochemical deposition through the application of 0.7 V for 30 s in a Ni+2 aqueous solution, followed by the cycling in KOH aqueous solution, in order to lead to thin films of CG homogeneously decorated with 3.79 ± 0.04 nm Ni(OH)2 nanoparticles. The glucose detection was optimized for the CG/Ni(OH)2 thin films reaching a low limit of detection (LD) of 0.34 ± 0.04 μmol L−1 for a wide linear range of detection (LRD) from 1 to 1000 μmol L−1 with good reproducibility, repeatability and low interferents effect. The CG/Ni(OH)2 thin films also exhibited very low LD for n-acetylcysteine, hydrochlorothiazide, and famotidine (0.54 ± 0.07, 2.38 ± 0.45, and 0.91 ± 0.48 μmol L−1, respectively) and a wide LRD (from 1 to 1000 μmol L−1).