Electrochemical sensor based on Ni-exchanged natural zeolite/carbon black hybrid nanocomposite for determination of vitamin B6

Abstract

The utilization of environmentally friendly nanoporous natural zeolite exchanged with Ni2+ ions (NiZ) and conductive carbon black (CB) in the fabrication of a novel and selective voltammetric sensor of vitamin B6 (VB6) is presented. The used clinoptilolite-rich zeolite material and CB were characterized in terms of morphology and textural properties. The superior properties of Ni-zeolite/carbon black modified glassy carbon electrode (NiZCB-GCE), arising from the synergistic effect of combining the unique features of zeolite and conductive carbon black, were confirmed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements. In the determination of VB6 with the use of differential pulse voltammetry (DPV), the optimization of the pH value of supporting electrolyte and instrumental parameters, as well as the interference study were performed. Under optimized conditions, the oxidation peak current at the potential +0.72 V vs. Ag | AgCl | 3 M KCl reference electrode was linear to the VB6 concentration in the range 0.050 to 1.0 mg L−1 (0.30–5.9 μmol L−1) (R = 0.9993). The calculated limit of detection (LOD, S/N = 3), equal to 15 μg L−1 (0.09 μmol L−1), was much better compared to chemically modified electrodes with other carbon-based materials. The RSD for 0.5 mg L−1 was in the range 2.5–5.4% (n = 4). The developed NiZCB-GCE was successfully applied to the determination of VB6 in commercially available multivitamin dietary supplements, food, and water samples. The obtained recoveries ranged from 95 to 106%. Graphical abstract

Fabrication of a bi-metallic metal organic framework nanocomposite for selective and sensitive detection of triclosan

“…The linear fitting slope was found to be E p = −0.053, which was close to the theoretical slope (−0.0590) derived from the Nernst equation. 59 From this, we can understand that the protons and electrons are in equal number and reacted at the same time. During sensing studies, having a neutral electrolyte medium is ideal and favorable for analyte interaction with the modified surface.…”

“…The linear tting slope was found to be E p = −0.053, which was close to the theoretical slope (−0.0590) derived from the Nernst equation. 59 From this, we can understand that the protons and electrons are…”

Electrochemical determination of vitamin B6 in pharmaceutical and energy drink samples

“…The peak current of VB6 increased progressively from pH 3.0 to 4.5, as shown in Figure 9B, and then fell gradually with increasing pH. From the fact that pKa values of VB6 are pKa1 = 5 and pKa2 = 8.96 [4,49] while pKas of phenylalanine are pKa1= 2.47 and pKa2 = 9.13 [32], the increase in current response with pH from 3.0 to 4.5 might be due to the increase in electrostatic attraction between the positively charged VB6 (pH ˂ 5.0) and negatively charged polymer film (pH ˃2.47). The charge density on both VB6 and poly (phenylalanine) increases as the pH rises, which causes the electrostatic attraction between VB6 and poly (phenylalanine) to decrease.…”

Potentiometric sensor for chromium(VI) using a composite of diphenylcarbazide-natural zeolite-modified membrane electrodes

“…Zeolite as a porous material provides uniformity in terms of shape and pore selectivity, which facilitates ions in accessing its framework for sensing purposes during electroanalytical studies [24,25]. The combination of ionophore and zeolite material results in several applications that have been investigated for analytical purposes [26][27][28].…”