Voltammetric and impedimetric behaviour of phytosynthesized nickel nanoparticles

Abstract

The biosynthesis of nickel nanoparticles from nickel chloride using Moringa oleifera leaf extract as reducing agent was successfully carried out; the formation of nickel nanoparticles was confirmed by the use of UVvisible spectroscopy, FTIR spectroscopy, atomic force microscopy, cyclic voltammetry and electrochemical impedance spectroscopy techniques. Optical property showed a colour change from faint light blue of the nickel chloride to dark reddish brown of the nickel nanoparticle after addition of the plant extract, while FTIR confirmed the possible biomolecule responsible for the reduction as anthraquinones; the UV-visible spectroscopy showed the wavelength of nickel nanoparticles at 297 nm, and atomic force microscopy gave images of the nickel nanoparticles as aggregate nanoclusters. Voltammetric and impedimetric behaviour of the nickel nanoparticles towards a one-electron-transfer redox probe was interrogated using cyclic voltammetry and impedance spectroscopy. The equivalent electrical circuit used to fit the measured impedance data indicates that the nanoparticles exhibited patterns characteristic of superimposed porous layer. Electron transfer rate constant K s and the apparent heterogeneous electron transfer constant K app were calculated as 6.18 9 10 18 and 1.60 9 10 -3 cm s -1 , respectively. Such high value is an indication of how fast the nickel nanoparticle can transfer electron from the nanoparticle to the underlying platinum electrode, implying that the nanoparticle can be a potential candidate in the fabrication of biosensors and in catalysis.

Square Wave Voltammetric Detection of Nitrite on Platinum Electrode Modified with Moringa oleifera Mediated Biosynthesized Nickel Nanoparticles

“…The electrochemical detection of nitrite is best performed in neutral pH phosphate buffer solution, (pH 7.4), this is because nitrite exists as nitrite ion (NO2 -) in neutral phosphate buffer solution but disproportionate to produce neutral nitric oxide (NO) in slightly acidic conditions [34], hence this study was carried out in phosphate buffer solution pH 7.4. This is a follow up to a previous work carried out by Mamuru et al [35] in which the electrochemical behavior of nickel nanoparticles synthesized using Moringa oleifera leaves extract was investigated.…”

Green Nanotechnology in Nigeria: The Research Landscape, Challenges and Prospects

“…employed leaf extract of Annona squamosa to biosynthesize chromium and nickel nanoparticles at neutral pH with SPR at 285 nm. In another study, Mamuru and Jaji (2015) biofabricated nickel nanoparticles using Moringa oleifera with prospective applications in catalysis and development of biosensors. Sodeinde et al (2016a) biosynthesized palladium nanoparticles using leaf extract of Bassella alba with particles of 10-14 nm.…”

Voltammetric Determination of Dopamine Using Glassy Carbon Electrode Modified with ZnO/Al2O3 Nanocomposite

“…In order to determine the drug in clinical samples, several techniques have been proposed such as ultra-high performance liquid chromatography/tandem mass spectrometry, chemiluminescence and spectrophotometry [5][6][7]. However, the electroanalytical methods are favor in terms of their high sensitivity, simplicity, low costs and uncomplicated equipment [8][9][10][11][12][13][14]. Furthermore, due to the important role of dopamine, sometimes, there is a need to online monitoring which can be capable through electrochemical methods.…”