A Magnetic Nanocomposite Modifier for Improved Ultrasensitive Detection of Hexavalent Chromium in Water Samples

In this work, different electrodes were employed for the determination of Cr(VI) by cathodic square-wave voltammetry (SWV) technique and adsorptive stripping (SWAdSV) in combination with diethylenetriaminepentaacetic acid. Using SWV, a comparison analytical performance bare glassy carbon electrode (GCE), ex situ (antimony-film—SbFE, copper-film—CuFE, bismuth-film—BiFE), GCE modified new magnetic nanocomposite (MNC) material was performed. First, MNC synthesized, i.e., MNPs@SiO2@Lys, where MNPs stands maghemite nanoparticles, coated thin amorphous silica (SiO2) layer, which additionally functionalized derived lysine (Lys). The crystal structure prepared MNCs confirmed X-ray powder diffraction (XRD), while morphology nano-size investigated field emission scanning electron microscopy (FE-SEM) transmission (TEM), TEM used to observe MNP core layer thickness. presence functional groups attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) surface analysis performed photoelectron (XPS). hydrophilicity also tested static contact angle measurements. Then, MNPs@SiO2@Lys applied onto SWV SWAdSV techniques. All effective trace determination. On other hand, required ultra-trace Cr(VI). technique, it shown that BiFE deposited resulted excellent (LOQ = 0.1 µg/L, linear concentration range 0.2–2.0 significantly higher sensitivity compared an RSD representing reproducibility 9.0%, average recovery 98.5%). applicability latter system demonstrated real sample.