This article was focused on the elaboration of NiFe-Polyaniline glucose sensors via electrochemical technique. Firstly, the PANi (polyaniline) fibers were synthesized by oxidation of the monomer ...aniline on FTO (fluorine tin oxide) substrate. Secondly, the Nickel–Iron nanoparticles (NiFe (NPs)) were obtained by the Chronoamperometry method on the Polyaniline surface. The NiFe-PANi hybrid electrode was characterized by scanning electron microscopy (SEM), force atomic microscopy (AFM), Fourier-transformed infrared (FTIR), and X-ray diffraction (XRD). The electrochemical glucose sensing performance of the NiFe alloy nanoparticle was studied by cyclic voltammetry and amperometry. The fabricated glucose sensor Ni–Fe hybrid material exhibited many remarkable sensing performances, such as low-response time (4 s), sensitivity (1050 μA mM−1 cm−2), broad linear range (from 10 μM −1 mM), and low limit of detection (LOD) (0.5 μM, S/N = 3). The selectivity, reliability, and stability of the NiFe hybrid material for glucose oxidation were also investigated. All the results demonstrated that the NiFe-PANi/FTO hybrid electrode is very promising for application in electrochemical glucose sensing.
Schematic oxidation of glucose on the NiFe(NPs)-PANi electrode. Display omitted
•Novel non-enzyme electrochemical NiFe-PANi hybrid electrode for glucose detection was synthesized.•PANi fibers were synthesized by oxidation of the monomer aniline on FTO.•Ni–Fe NPs were obtained by the Chronoamperometry method on the PANi surface.•NiFe-PANi showed good selectivity, reliability, and stability for glucose detection.
CoNi films were elaborated by electrodeposition onto FTO substrates using a chloride bath with a metallic ion molar ratio Co
2+
/Ni
2+
equals 1/1. Three samples were elaborated for different ...potentials ranging from −1.6 to −1.5 V. The structure and the morphology of CoNi films were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The chemical compositions are obtained using energy dispersive X-ray (EDX) and the magnetic properties were studied using a vibrating sample magnetometer (VSM). From X-ray diffraction, we have shown the presence of the FCC phase of CoNi binary alloy with a well-pronounced texture along the < 111 > , < 200 > , and < 220 > planes for all samples. We have found that the applied potential has an influence on crystallite sizes. Besides, a moderate change in the lattice parameter has been observed with increasing applied potential. The AFM images show that the applied potential changes the morphology and the surface roughness of CoNi films. In addition, the SEM images confirm the granular morphology of CoNi deposits and show a good relationship between voltage and grain size. The EDX spectrums confirm the deposition of the cobalt and the nickel on the FTO substrate and show the precedence deposition of Co compared with Ni. The extracted coercive field Hc and squareness from the hysteresis loops explained the good correlation between the magnetic and structural properties of CoNi thin films.
Keywords NiFe nanoparticles; Polyaniline; Glucose; Non-enzymatic sensor; Selectivity; Reliability Highlights * Novel non-enzyme electrochemical NiFe-PANi hybrid electrode for glucose detection was ...synthesized. * PANi fibers were synthesized by oxidation of the monomer aniline on FTO. * Ni--Fe NPs were obtained by the Chronoamperometry method on the PANi surface. * NiFe-PANi showed good selectivity, reliability, and stability for glucose detection. This article was focused on the elaboration of NiFe-Polyaniline glucose sensors via electrochemical technique. Firstly, the PANi (polyaniline) fibers were synthesized by oxidation of the monomer aniline on FTO (fluorine tin oxide) substrate. Secondly, the Nickel--Iron nanoparticles (NiFe (NPs)) were obtained by the Chronoamperometry method on the Polyaniline surface. The NiFe-PANi hybrid electrode was characterized by scanning electron microscopy (SEM), force atomic microscopy (AFM), Fourier-transformed infrared (FTIR), and X-ray diffraction (XRD). The electrochemical glucose sensing performance of the NiFe alloy nanoparticle was studied by cyclic voltammetry and amperometry. The fabricated glucose sensor Ni--Fe hybrid material exhibited many remarkable sensing performances, such as low-response time (4 s), sensitivity (1050 muA mM.sup.-1 cm.sup.-2), broad linear range (from 10 muM -1 mM), and low limit of detection (LOD) (0.5 muM, S/N = 3). The selectivity, reliability, and stability of the NiFe hybrid material for glucose oxidation were also investigated. All the results demonstrated that the NiFe-PANi/FTO hybrid electrode is very promising for application in electrochemical glucose sensing. Author Affiliation: (a) Research Center in Industrial Technologies CRTI, P.O. Box 64, Cheraga, 16014, Algiers, Algeria (b) Nuclear Research Centre of Algiers, 2 Bd Frantz Fanon, Bp 399, Alger-Gare, Algiers, Algeria (c) Laboratoire de Physique et Chimie des Materiaux (LPCM), Universite Mouloud Mammeri de Tizi-Ouzou, RP 15000, Algeria (d) Laboratoire Biotechnologies, Ecole Nationale Superieure de Biotechnologie, Ville Universitaire Ali Mendjeli, BP E66 25100, Constantine, Algeria (e) Center for Advanced Chemistry, Institute of Research and Development, Duy Tan University, 03 Quang Trung, Da Nang 550000, Vietnam (f) The Faculty of Environmental and Chemical Engineering, Duy Tan University, 03 Quang Trung, Da Nang 550000, Vietnam * Corresponding author. Research Center in Industrial Technologies CRTI, P.O. Box 64, Cheraga, 16014, Algiers, Algeria. Article History: Received 31 December 2020; Revised 14 February 2021; Accepted 26 February 2021 (miscellaneous) Handling Editor: Dr. Jose Luis Domingo Byline: Delloula Lakhdari d.lakhdari@crti.dz (a,c,*), Abderrahim Guittoum (b), Nassima Benbrahim (c), Ouafia Belgherbi (a), Mohammed Berkani m.berkani@ensbiotech.edu.dz (d,***), Yasser Vasseghian yasservasseghian@duytan.edu.vn (e,f,**), Nadjem Lakhdari n.lakhdari@ensbiotech.edu.dz (d,***)
A nanostructured nickel–iron alloy having the Ni
40
Fe
60
composition was prepared through the mechanical alloying of the elemental powders in a high-energy ball mill P7 under an argon atmosphere. ...The microstructural, structure defects, and hyperfine properties during mechanical alloying were characterized by X-ray diffraction, scanning electron microscopy, and Mössbauer spectroscopy. The analysis of XRD spectra shows that the final product obtained was a nanostructured fcc-Ni(Fe)-rich phase. Whereas a more precise analysis by Mössbauer spectroscopy indicates that, in addition to paramagnetic phase rich with Ni, disordered ferromagnetic solid solutions fcc-Ni(Fe) and bcc-Fe(Ni) are present. The resulting nanostructure is demonstrated in accordance with the concept of dislocations; the dislocation densities were found to be around 5 × 10
16
m
−2
after 50 h milling.
Nanocrystalline Fe
90
Ni
10
alloys were synthesized by mechanical alloying, starting from a powder mixture of elemental Fe and Ni. The phase evolution and magnetic properties were investigated, as a ...function of milling time, using the X-ray diffraction (XRD), the vibrating sample magnetometer (VSM), and the
57
Fe Mössbauer spectroscopy. From XRD results, we concluded the formation, after 13 h of milling, of a disordered phase
α
-Fe(Ni) (bcc). It has been shown that the increase of milling time decreases the crystallites size and increases the microstrains and the lattice parameter. When the crystallites size decreases, the coercive field,
H
c
, decreases first, then increases and finally reaches a constant value of about 26 Oe. During the periode of the alloy formation, the saturation magnetization,
M
s
, increases with decreasing crystallite size and reaches the highest value of 212 emu/g after 27 h of milling, then,
M
s
remains constant up to 48 h of milling. The adjustment of Mössbauer spectra revealed that the fraction of the (bcc)
α
-Fe(Ni) phase increased with milling time. After 13 h of milling, only the (bcc)
α
-Fe(Ni) phase is observed.
Nanocrystalline Fe50Ni50 alloy samples were prepared by the mechanical alloying process using planetary high-energy ball mill. The alloy formation and different physical properties were investigated ...as a function of milling time, t, (in the 0-50h range) by means of the X-ray diffraction (XRD) technique, scanning electron microscopy (SEM), energy dispersive X-ray (EDAX), Mossbauer spectroscopy and the vibrating sample magnetometer (VSM). The complete formation of gamma-FeNi is observed after 24h milling. When milling time increases from 0 to 50h, the lattice parameter increases towards the Fe50Ni50 bulk value, the grain size decreases from 67 to 13nm, while the strain increases from 0.09% to 0.41%. Grain morphologies at different formation stages were observed by SEM. Saturation magnetization and coercive fields derived from the hysteresis curves are discussed as a function of milling time.
A particular interest has been given to the study of Fe100-xPdx (x=15, 20 and 36) alloys. Alloy thin films, obtained by thermal evaporation technique, have been investigated by X-ray diffraction, ...magnetization and Mössbauer effect measurements. All of these alloys are crystalline: a bcc phase for x=15 and a bcc-fcc mixed phases for x=20 and x=36.The magnetic and structural properties measurements, performed on these alloys, show the fcc phase appearance as well as the structural transition between the bcc and bcc-fcc mixed phases.
In this work, we investigated the effect of substrate on the structural, morphological, and magnetic properties of electrodeposited CoNi thin films from a chloride bath. Three samples of CoNi films ...were deposited at room temperature onto different substrates: FTO, ITO, and Cu. Electrochemical studies were performed using cyclic voltammetry experiments. Energy-dispersive X-ray spectroscopy (EDX) showed that all the samples had a cobalt content of more than 80%. X-ray diffraction (XRD) spectra revealed that the films deposited on Cu had a face-centered cubic (FCC) phase, while those deposited on ITO and FTO had a mixture of hexagonal close-packed (HCP) and FCC phases. The lattice parameter (a) and crystallite size (D) were strongly dependent on the substrate. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to observe the morphology of the films. All the samples had a granular morphology with spherical grains, but the roughness and surface distribution varied with the substrate. The magnetic properties of the films, such as coercivity (Hc) and squareness (S), were investigated using a vibrating sample magnetometer (VSM). The results showed that Hc and S were both affected by the substrate and the film composition. Overall, our results showed that the substrate had a significant effect on the structural, morphological, and magnetic properties of electrodeposited CoNi thin films. These findings could be used to design and optimize CoNi thin films for specific applications.
PDF
