Synthesis of NiCo₂O₄/Nano-ZSM-5 nanocomposite material with enhanced electrochemical properties for the simultaneous determination of ascorbic acid, dopamine, uric acid and tryptophan

Abstract

NiCo 2 O 4 /Nano-ZSM-5 nanocomposite materials were prepared by the calcination of the physical mixture of NiCo 2 O 4 and Nano-ZSM-5. Materials were characterized by the complementary combination of X-ray diffraction, N 2 -adsorption and electron microscopic techniques. Electrochemical sensor based on NiCo 2 O 4 /Nano-ZSM-5 nanocomposite was constructed for the simultaneous determination of ascorbic acid, dopamine, uric acid, and tryptophan. Among the materials investigated in this study, NiCo 2 O 4 (30 %)/Nano-ZSM-5 modified glassy carbon electrode exhibited the highest electro catalytic activity with excellent stability, sensitivity, and selectivity. Under the optimum conditions, a wide linear range was obtained from 1-1200 µM for ascorbic acid, 0.6-900 µM for dopamine, 0.9-1000 µM for uric acid, and 0.9-1000 µM for tryptophan. The detection limit was found to be 0.8, 0.5, 0.7 and 0.7 µM for ascorbic acid, dopamine, uric acid, and tryptophan, respectively. The analytical performance of the developed sensor was demonstrated in the determination of ascorbic acid and dopamine in the commercial pharmaceutical preparations (vitamin C tablets and dopamine injections) and uric acid in human urine samples.The solution pH affects the electrochemical behavior of AA, DA, UA, and Trp. The effect of the pH on the electro-catalytic oxidation of AA, DA, UA, and Trp was investigated at NiCo 2 O 4 (30 %)/Nano-ZSM-5/GCE by varying the pH of the supporting electrolyte in a wider range (1-9) using DPV in a solution containing equal concentrations (10 µM) of AA, DA, UA and Trp. The anodic peak current was found to increase with increase in the pH of the medium, with a maximum anodic peak current at pH 3.5 (Fig. S8a). After pH 3.5, it was further decreased.

Mechanistic study on the facet etching effect of silver nanoprisms in the presence of halide ions and their application in the colorimetric sensing of metformin hydrochloride

“…Normally, the optimization process has been carried out by one-variable-at-a-time which only one parameter is changed, others are kept at a constant level 34,35 . Of which Cl is more common as many drugs are saved as hydrochloride of the active ingredients, so the assay of active ingredients can be indirectly determined by the assaying Cl -.…”

One‐Pot Fabrication of Dendritic NiO@carbon–nitrogen Dot Electrodes for Screening Blood Glucose Level in Diabetes

“…The following Cottrell equation (Equation ( 1) ) was used to calculate the diffusion coeffi cient [ 33 ] I nFAD cp t ) were in good competition with the previous reported values. [ 34 ] This competition could be attributed to the synergetic effect of the 3D porous NDs with C dot spheres, which enhanced the mass transfer rate. [ 35 ] The electrocatalytic rate constant of the NCD sphere electrode toward the oxidation of Glu could be deduced from the chronoamperometry experiments [see Figure S13, Supporting Information] and calculated via Equation ( 2) [ 34 ] I…”

Electrochemical Sensor Platforms Based on Nanostructured Metal Oxides, and Zeolite‐Based Materials

“…Cu(II) doped zeolite A for AA detection,methylene blue incorporated into mordenite type zeolite for AA detection, graphite−zeolite‐modified electrode doped with iron (III) for UA detection have been described in the literature ) . The linear ranges were obtained from 1–1200 μM for AA, 0.6–900 μM for DA, 0.9‐1000 μM for UA, and 0.9–1000 μM for Trp .…”