Electrochemical studies and sensing of iodate, periodate and sulphite ions at carbon nanotubes/ Prussian blue films modified platinum electrode

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Nutrient composition of watermelon (Citrullis lanatus (Thunb.) Matsum.&Nakai) and egusi melon (Citrullus colocynthis (L.) Schrad.) seeds

This study investigated the nutrient composition of the seeds of two cultivars of Citrullis lanatus (\u27Rhotmas\u27 and \u27Sugar Baby\u27) and compared it with Citrullus colocynthis. The moisture content, ash, crude fiber, ether extract, crude protein and true protein ranged from 5.43 to 6.82, 2.78 to 3.72, 1.66 to 3.94, 55.7 to 58.7, 19.16 to 25.18 and 10.8 to 13%, respectively. The starch content, total sugar and reducing sugar varied between 143.7 and 172.7, 53.7 and 96.5, 5.6 and 9.5 mg/g, respectively. Iron, copper, zinc, calcium and magnesium ranged from 191 to 211, 20.12 to 35.03, 68.97 to 92.57, 98.79 to 233, and 79.75 to 123.9 mg/kg, respectively. Heavy metals (lead and cadmium) and antinutrients (phytate, oxalate and cyanide) were below deleterious levels. Arginine, glutamic acid and aspartic acids were the most abundant amino acids, whereas lysine was the limiting amino acid. It is concluded that watermelon seeds were better in nutritional value compared to egusi melon seeds and therefore could be regarded as a potential sources of food if exploited

Electrocatalysis of Lindane Using Antimony Oxide Nanoparticles Based-SWCNT/PANI Nanocomposites

This work describes the chemical synthesis of antimony oxide nanoparticles (AONPs), polyaniline (PANI), acid functionalized single-walled carbon nanotubes (fSWCNTs), and the nanocomposite (AONP-PANI-SWCNT) as catalyst for the trace detection of lindane. Successful synthesis of the nanomaterials was confirmed by Fourier transform infrared (FT-IR) spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, x-ray diffraction (XRD) spectroscopy, and scanning electron microscopy (SEM). Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used for investigating the electrochemical behavior of the modified electrodes in the ferrocyanide/ferricyanide ([Fe(CN)6]4−/[Fe(CN)6]3−) redox probe. GCE-AONP-PANI-SWCNT exhibited faster electron transport properties as well as higher electroactivity as compared to bare-GCE, GCE-AONPs, GCE-PANI, and GCE-SWCNT electrodes. Electrocatalytic studies further showed that GCE-AONP-PANI-SWCNT modified electrode was stable (after 20 scans) with only a small current drop in lindane (0.57%). The GCE-AONP-PANI-SWCNT electrode with low detection limit of 2.01 nM performed better toward the detection of lindane as compared to other studies in literature. The GCE-AONP-PANI-SWCNT electrode is highly selective toward the detection of lindane in the presence of various organic and inorganic interfering species. Real sample analysis of river water and tap water samples using the developed sensor gave satisfactory percentage recoveries therefore confirming the potential of the proposed sensor for practical application

Voltammetric and impedance studies of phenols and Its derivatives at carbon nanotubes/Prussian bluefilms platinum modified electrode

The electrochemical oxidation of phenol (Ph), 4-chlorophenol (4-ClPh) and 4-nitrophenol (4-NPh) at a platinum electrode modified with and without multi-walled carbon nanotubes/Prussian blue nanocomposite in a pH 7.0 phosphate buffer electrolyte was investigated by cyclic voltammetry (CV) and impedance measurements. The modified electrodes were characterised using techniques such as transmission electron microscopy (TEM), electron X-ray dispersive spectroscopy (XRD), cyclic voltammetry (CVs) and electrochemical impedance spectroscopy (EIS)..

Electrocatalytic properties of prussian blue nanoparticles supported on poly(m-aminobenzenesulfonic acid)–functionalized single-walled carbon nanotubes toward the detection of dopamine

Edged plane pyrolytic graphite electrode (EPPGE) was modified with and without Prussian blue (PB) nanoparticles and polyaminobenzene sulphonated single-walled carbon nanotubes (SWCNTPABS) using the chemical deposition method. The electrodes were characterised using microscopy, spectroscopy and electrochemical techniques. Results showed that edged plane pyrolytic graphite-single-walled carbon nanotubes-prussian blue (EPPGE-SWCNT-PB) electrode gave the best dopamine (DA) current response which increases with increasing PB layers

The Potential of Some Non-Conventional Vegetable Oils in Biodiesel Applications

This work studied the potentials of some non-conventional oils biodiesel as an alternative to biodiesel made from a conventional seed oil (palm kernel oil), and petroleum-based diesel. The fruits of three non-conventional oilseeds, namely:PerseaAmericana (Avocado pear), Irvingiagabonenses (Dica nut) and Darcryodesedulis (Native pear)were obtained from local markets in Ile-Ife, Osun State Nigeria while petroleum-based diesel (PBD) used for comparative study was obtained commercially.The outer fleshylayers of the fruitswere separated from the seeds while both were air-dried for some days and later milled. The oils extracted from the milled samples were esterified to produce biodiesel usingmethanol in the presence of NaOH as catalyst. The biodiesels were analyzed for their fuel properties using standard methods.Results showed that the biodiesel yield ofIrvingiagabonensisoil diesel (IGOD),Darcryodesedulisoil diesel (DEOD) and Persia americanaoil diesel (PAOD) were94%, 82% and 96% respectively. These values compared favourably with that of palm kernel oil diesel (PKOD) (91%) produced under same conditions, and with the literature standard yield of 96.5% set for biodiesel. The pour pointsof PKOD, PAOD and DEOD were3, -6 and 1oC,respectively, with PAOD pour point very close to that of PBD (≥-10oC) obtained under similar experimental conditions. Except for IGOD, all the oils have pour points within the standard range of -15 to 16oC set for biodiesel suggesting the suitability of the oils for biodiesel applications.The iodine values of the biodiesel ranged between 9.64 and 16.52 meq/kg and agreed closely with 12-18 meq/kg reported in literature for PKOD. The biodiesel blend with PBD in the ratio 10:90, 20:80, 30:70 and 40:60 demonstratedimprovedphysico-chemical properties (including smoke point, flash point, cloud point, pour point, density, viscosity and acid value) that could meet the fluidity requirements for biodiesel applications

Supercapacitive properties of symmetry and the asymmetry two electrode coin type supercapacitor cells made from MWCNTS/nickel oxide nanocomposite

Please read abstract in article.http://www.electrochemsci.orgnf201

Comparative supercapacitive properties of asymmetry two electrode coin type supercapacitor cells made from MWCNTS/cobalt oxide and MWCNTs/iron oxide nanocomposite

Supercapacitive properties of synthesized metal oxide nanoparticles (MO) vis a vis iron oxides (Fe2O3) and cobalt oxide (Co3O4) nanoparticles integrated with multi-walled carbon nanotubes (MWCNT) in a two-electrode coin cell type asymmetry supercapacitor assembly was investigated. The synthesised MO and nanocomposite films were characterised using techniques such as transmission electron microscopy (TEM), scan electron microscopy (SEM), electron dispersive X-ray spectroscopy (EDX) and X-ray diffraction spectroscopy (XRD). The supercapacitance of the asymmetry MWCNT-MO based supercapacitor in 1 M H2SO4 and 1 M Na2SO4 electrolytes was measured using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic constant current charge-discharge (CD) techniques. The asymmetry supercapacitors MWCNT-Fe2O3|MWCNT and MWCNT-Co3O4|MWCNT gave the highest specific capacitance (SC) values of 439.94 mFcm-2 (or 64.74 Fg-1) and 425.83 mFcm-2 (or 45.79 Fg−1) respectively in 1 M H2SO4 using charge-discharge technique. Results obtained from charge-discharge experiment are much higher compared with those obtained using the CV technique since it is the most reliable and accurate method. The values compared favorably and higher compared to those reported in literature using similar technique. MWCNT-Fe2O3|MWCNT cell gave specific power (SP) and specific energy (SE) of 19.31 Wkg-1 and 2.68 WhKg-1 respectively in 1 M H2SO4, while the energy deliverable efficiency (/%) of the cell is 99.6 and 91.3% in 1 M H2SO4 and 1 M Na2SO4 respectively.http://www.electrochemsci.orgam201

Development of Electrochemical Nanosensor for the Detection of Malaria Parasite in Clinical Samples

In this study, electrochemical nanosensors were developed from the synthesized metal oxide (MO) nanoparticles by supporting it on a gold electrode (Au). The activity of the developed nanosensor toward the detection of malaria biomarker (β-hematin) was determined and the optimum conditions at which the maximum detection and quantification occurred were established. β-Hematin current response at the sensors was higher when compared with the bare Au electrode and followed the order Au-CuO (C) > Au-CuO (M) > Au-Fe2O3 (M) > Au-Fe2O3 (C) > Au-Al2O3 (M) > Au-Al2O3 (C) > bare Au. The developed sensors were stable with a relatively low current drop (10.61–17.35 %) in the analyte. Au-CuO sensor had the best performance toward the biomarker and quantitatively detected P. berghei in infected mice's serum samples at 3.60–4.8 mM and P. falciparum in human blood serum samples at 0.65–1.35 mM concentration