Nickel Hydroxide Nanoparticles on Screen-printed Electrodes as an Impedimetric Non-enzymatic Glucose Sensor

In this study, the electrodeposition of nickel hydroxide nanoparticles onto a screen-printed electrode (Ni(OH)(2)/SPE) is described. Ni(OH)(2)/SPE is proposed as an alternative non-enzymatic glucose sensor based on Electrochemical Impedance Spectroscopy (EIS) measurements. The SPEs were modified by the cathodic electrodeposition of nickel, from a solution containing 0.010 M Ni(NO3)(2) and 1 M NH4Cl, at -1.3 V for 60 seconds. The SEM images show a uniform distribution of nickel spherical nanoparticles, with 60 nm average particle size. However, such morphology is not observed when the electrodeposition occurs in the absence of NH4Cl. The electrochemical properties of the sensor were carefully evaluated by Cyclic Voltammetry. Ni(OH)(2)/SPE shows a remarkable electrocatalytic behavior towards the oxidation of glucose in 0.1 M KOH. EIS measurements were carried out for Ni(OH)(2)/SPE and a single-frequency impedance method is proposed as transduction principle for glucose determination. The analysis of each parameter of complex impedance was performed. The best linear response was obtained for the module of impedance (|Z|) in the range of 0-2 mM of glucose at 0.1 Hz (R-2 = 0.992) with a slope of 0.137 K Omega(-1).mM(-1) of glucose. Finally, Ni (OH)(2)/SPE was utilized for quantification of glucose in blood samples.