A new sustainable approach using a composite material based on dimethylglyoxime and graphite immobilized on a 3D printed support for selective nickel detection

Abstract

In this work, the development of a low-cost electrochemical device (U$ 0.02 per electrode) from the immobilization of a composite material (CM) based on graphite powder, dimethylglyoxime (DMG) and nail polish, on a 3D printed acrylonitrile butadiene styrene (ABS) support was proposed for direct, sensitive and selective determination of Ni(II) by square-wave cathodic adsorptive stripping voltammetry (SWCAdSV) in a reduction potential of −1.15 V (vs Ag|AgCl|KCl(sat)). The CM was properly characterized by X-ray diffraction (XRD) and Raman spectroscopy, additionally, the electrode surface of the proposed device (3Ds-CM/DMG) was morphologically characterized through images obtained by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The electrode was applied as a proof of concept for monitoring Ni(II) levels in spiked tap water and synthetic urine samples. Under optimal analysis conditions, the developed method showed a good linear working range with concentrations ranging from 5 to 100 µg L−1, detectability (limit of detection) of 1.693 µg L−1, and excellent precision with relative standard deviation (RSD) of 2.9%. The doped samples at three concentration levels presented recovery values from 93.8 to 103.1%, using as a sample preparation step a simple dilution in supporting electrolyte. Furthermore, the results were analytically validated by statistical comparison with results obtained by flame atomic absorption spectrometry (F AAS). Finally, the electrodes showed RSD of 6.1% for construction reproducibility, which allows inferring that the proposed electrode proves to be a promising analytical tool with wide applicability.