1
|
Sebabi M, Mabuba N, Pillay K, Malinga SP. Hyperbranched-Polyethylenimine-Functionalized Coal Fly Ash as an Adsorbent for the Removal of Hexavalent Chromium and Reuse as a Dye Photocatalyst. ACS Omega 2024; 9:8954-8972. [PMID: 38434891 PMCID: PMC10905742 DOI: 10.1021/acsomega.3c06491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 12/27/2023] [Accepted: 01/10/2024] [Indexed: 03/05/2024]
Abstract
Coal fly ash (CFA) has been extensively researched as an adsorbent for heavy metals, but its application is limited by its low adsorption capacity. The modification of CFA with hyperbranched polymers results in improved adsorption capacities. Hyperbranched polyethylenimine (HPEI) is a hyperbranched polymer containing NH2 groups that can bind with heavy metal ions through complexation or electrostatic interactions. In this study, CFA-HPEI adsorbents with various HPEI loadings (1-5%) were prepared and evaluated for the removal of Cr(VI). The successful incorporation of HPEI onto CFA was confirmed using Fourier transform infrared, elemental analysis, and X-ray photoelectron spectroscopy (XPS). The 3% CFA-HPEI loaded adsorbent resulted in optimum results when the effect of pH and adsorbent dosage was studied. The pseudo-second-order kinetics model best described the adsorption kinetics at an initial concentration of 20 mg/L. The Freundlich adsorption isotherm model best fitted the equilibrium adsorption data with a maximum adsorption capacity of 85.93 mg/g. The Cr-loaded adsorbent was reused as a photocatalyst to degrade methylene blue (MB) in the presence of visible light. The loaded adsorbent degraded 98.9% of MB (5 mg/L) within 180 min and was accompanied by compounds with m/z of 173 and 234, corresponding to the intermediate degradation of Azure A. The XPS analysis confirmed the coexistence of Cr(III) and Cr(VI) on the surface of the adsorbent. In addition, the loaded adsorbent exhibited good stability following MB degradation with no structural changes observed. Thus, CFA-HPEI adsorbents can be utilized as low-cost adsorbents for the remediation of toxic Cr(VI) from water and wastewater. The Cr-loaded CFA-HPEI adsorbent can be effectively reused as a photocatalyst, thus reducing environmental pollution.
Collapse
Affiliation(s)
- Molahlegi
Orienda Sebabi
- Department
of Chemical Sciences, University of Johannesburg, P.O. Box 17011, Doornfontein 2028, South Africa
- Spectrum, University
of Johannesburg, P.O. Box 524, Auckland Park 2006, South Africa
| | - Nonhlangabezo Mabuba
- Department
of Chemical Sciences, University of Johannesburg, P.O. Box 17011, Doornfontein 2028, South Africa
| | - Kriveshini Pillay
- Department
of Chemical Sciences, University of Johannesburg, P.O. Box 17011, Doornfontein 2028, South Africa
| | - Soraya Phumzile Malinga
- Department
of Chemical Sciences, University of Johannesburg, P.O. Box 17011, Doornfontein 2028, South Africa
| |
Collapse
|
2
|
Bopape DA, Tetana Z, Mabuba N, Motaung DE, Hintsho-Mbita NC. Biosynthesis of TiO2 nanoparticles using Commelina benghanlensis for the photodegradation of methylene blue dye and antibiotics: Effect of plant concentration. Results in Chemistry 2023. [DOI: 10.1016/j.rechem.2023.100825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
|
3
|
Masekela D, Hintsho-Mbita NC, Sam S, Yusuf TL, Mabuba N. Application of BaTiO3-based catalysts for piezocatalytic, photocatalytic and piezo-photocatalytic degradation of organic pollutants and bacterial disinfection in wastewater: A comprehensive review. ARAB J CHEM 2022. [DOI: 10.1016/j.arabjc.2022.104473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
|
4
|
Ojo BO, Arotiba OA, Mabuba N. Sonoelectrochemical oxidation of sulfamethoxazole in simulated and actual wastewater on a piezo-polarizable FTO/BaZr x Ti (1-x)O 3 electrode: reaction kinetics, mechanism and reaction pathway studies. RSC Adv 2022; 12:30892-30905. [PMID: 36349008 PMCID: PMC9614641 DOI: 10.1039/d2ra04876k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 10/13/2022] [Indexed: 11/14/2022] Open
Abstract
The sonoelectrochemical (SEC) oxidation of sulfamethoxazole (SMX) in simulated and actual wastewater on FTO/BaZr(0.1)Ti(0.9)O3, FTO/BaZr(0.05)Ti(0.95)O3 and FTO/BaTiO3 electrodes is hereby presented. Electrodes from piezo-polarizable BaZr(0.1)Ti(0.9)O3, BaZr(0.05)Ti(0.95)O3, and BaTiO3 materials were prepared by immobilizing these materials on fluorine-doped tin dioxide (FTO) glass. Electrochemical characterization performed on the electrodes using chronoamperometry and electrochemical impedance spectroscopy techniques revealed that the FTO/BaZr(0.1)Ti(0.9)O3 anode displayed the highest sonocurrent density response of 2.33 mA cm-2 and the lowest charge transfer resistance of 57 Ω. Compared to other electrodes, these responses signaled a superior mass transfer on the FTO/BaZr(0.1)Ti(0.9)O3 anode occasioned by an acoustic streaming effect. Moreover, a degradation efficiency of 86.16% (in simulated wastewater), and total organic carbon (TOC) removal efficiency of 63.16% (in simulated wastewater) and 41.47% (in actual wastewater) were obtained upon applying the FTO/BaZr(0.1)Ti(0.9)O3 electrode for SEC oxidation of SMX. The piezo-polarizable impact of the FTO/BaZr(0.1)Ti(0.9)O3 electrode was further established by the higher rate constant obtained for the FTO/BaZr(0.1)Ti(0.9)O3 electrode as compared to the other electrodes during SEC oxidation of SMX under optimum operational conditions. The piezo-potential effect displayed by the FTO/BaZr(0.1)Ti(0.9)O3 electrode can be said to have impacted the generation of reactive species, with hydroxyl radicals playing a predominant role in the degradation of SMX in the SEC system. Additionally, a positive synergistic index obtained for the electrode revealed that the piezo-polarization effect of the FTO/BaZr(0.1)Ti(0.9)O3 electrode activated during sonocatalysis combined with the electrochemical oxidation process during SEC oxidation can be advantageous for the decomposition of pharmaceuticals and other organic pollutants in water.
Collapse
Affiliation(s)
- Babatope O. Ojo
- Department of Chemical Sciences, University of JohannesburgDoornfontein 2028JohannesburgSouth Africa
| | - Omotayo A. Arotiba
- Department of Chemical Sciences, University of JohannesburgDoornfontein 2028JohannesburgSouth Africa,Centre for Nanomaterials Science Research, University of JohannesburgSouth Africa
| | - Nonhlangabezo Mabuba
- Department of Chemical Sciences, University of JohannesburgDoornfontein 2028JohannesburgSouth Africa,Centre for Nanomaterials Science Research, University of JohannesburgSouth Africa
| |
Collapse
|
5
|
Ojo BO, Arotiba OA, Mabuba N. Evaluation of FTO-BaTiO3/NiTiO3 electrode towards sonoelectrochemical degradation of emerging pharmaceutical contaminants in water. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2022.129201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
6
|
Masekela D, Hintsho-Mbita NC, Ntsendwana B, Mabuba N. Thin Films (FTO/BaTiO 3/AgNPs) for Enhanced Piezo-Photocatalytic Degradation of Methylene Blue and Ciprofloxacin in Wastewater. ACS Omega 2022; 7:24329-24343. [PMID: 35874262 PMCID: PMC9301950 DOI: 10.1021/acsomega.2c01699] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
In this study, we investigate the ability of barium titanate/silver nanoparticles (BaTiO3/AgNPs) composites deposited on a fluorine-doped tin oxide (FTO) glass using tape-casting method to produce piezoelectric thin film (FTO/BaTiO3/AgNPs) for piezocatalytic, photocatalytic, and piezo-photocatalytic degradation of methylene blue (MB) and ciprofloxacin (CIP) in wastewater. The prepared piezoelectric materials (BaTiO3 and BaTiO3/AgNPs) were characterized using XRD, SEM, TEM, EDS, UV-DRS, TGA, PL, BET, EIS, and chronoamperometry. The UV-DRS showed the surface plasmon resonance (SPR) of Ag nanoparticles on the surface of BaTiO3 at a wavelength of 505 nm. The TEM images revealed the average Ag nanoparticle size deposited on the surface of BaTiO3 to be in the range of 10-15 nm. The chronoamperometry showed that the photoreduction of silver nanoparticles (AgNPs) onto BaTiO3 (BTO) resulted in a piezo-electrochemical current enhancement from 0.24 to 0.38 mA. The composites (FTO/BaTiO3/AgNPs) achieved a higher degradation of MB and CIP when the photocatalysis and piezocatalysis processes were merged. Under both ultrasonic vibration and UV light exposure, FTO/BTO/AgNPs degraded about 72 and 98% of CIP and MB from wastewater, respectively. These piezoelectric thin films were shown to be efficient and reusable even after five cycles, suggesting that they are highly stable. Furthermore, the reactive oxygen species studies demonstrated that hydroxyl radicals (·OH) were the most effective species during degradation of MB, with minor superoxide radicals (·O2 -) and holes (h+). From this study, we were able to show that these materials can be used as multifunctional materials as they were able to degrade both the dye and pharmaceutical pollutants. Moreover, they were more efficient through the piezo-photocatalytic process.
Collapse
Affiliation(s)
- Daniel Masekela
- Department
of Chemical Sciences (formerly known as Applied Chemistry), University of Johannesburg, P.O Box 17011, Doornfontein, Johannesburg 2028, South Africa
| | | | - Bulelwa Ntsendwana
- Energy,
Water, Environmental and Food Sustainable Technologies (EWEF-SusTech), Johannesburg 1709, South Africa
| | - Nonhlangabezo Mabuba
- Department
of Chemical Sciences (formerly known as Applied Chemistry), University of Johannesburg, P.O Box 17011, Doornfontein, Johannesburg 2028, South Africa
| |
Collapse
|
7
|
Yusuf TL, Orimolade BO, Masekela D, Mamba B, Mabuba N. The application of photoelectrocatalysis in the degradation of rhodamine B in aqueous solutions: a review. RSC Adv 2022; 12:26176-26191. [PMID: 36275103 PMCID: PMC9490539 DOI: 10.1039/d2ra04236c] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 09/07/2022] [Indexed: 12/14/2022] Open
Abstract
The pollution of the water environment by industrial effluents is an ongoing challenge due to the rate of industrialisation and globalisation. Photoelectrocatalysis (PEC), an electrochemical advanced oxidation process, has proven to be an effective method for removing organics from wastewater. Photoelectrocatalysis is environmentally benign, cost-effective and easy to operate. In this present review, we examine the recent progress in the removal of rhodamine B dye, a common constituent of textile effluent released into the environment, through photoelectrocatalytic degradation. We present a detailed discussion on the use of different kinds of unmodified and modified photoanodes that have been explored for the photoelectrocatalytic removal of this dye. More importantly, discussions are presented on the mechanisms and kinetics of the degradation of rhodamine B dye using these photoanodes. Hence, this review will be beneficial for researchers in developing future projects in the area of wastewater treatments through photoelectrocatalysis. The pollution of the water environment by industrial effluents is an ongoing challenge due to the rate of industrialisation and globalisation.![]()
Collapse
Affiliation(s)
- Tunde Lewis Yusuf
- Department of Chemical Sciences, University of Johannesburg, Doornfontein, P.O. BOX 17011, 2028 Johannesburg, South Africa
| | - Benjamin O. Orimolade
- Institute for Nanotechnology and Water Sustainability (iNanoWS), College of Science, Engineering and Technology, University of South Africa, Private Bag X6, Florida Science Campus, 1709 Johannesburg, South Africa
| | - Daniel Masekela
- Department of Chemical Sciences, University of Johannesburg, Doornfontein, P.O. BOX 17011, 2028 Johannesburg, South Africa
| | - Bhekie Mamba
- Institute for Nanotechnology and Water Sustainability (iNanoWS), College of Science, Engineering and Technology, University of South Africa, Private Bag X6, Florida Science Campus, 1709 Johannesburg, South Africa
| | - Nonhlangabezo Mabuba
- Department of Chemical Sciences, University of Johannesburg, Doornfontein, P.O. BOX 17011, 2028 Johannesburg, South Africa
| |
Collapse
|
8
|
Yusuf T, Oladipo SD, Zamisa S, Kumalo HM, Lawal IA, Lawal MM, Mabuba N. Design of New Schiff-Base Copper(II) Complexes: Synthesis, Crystal Structures, DFT Study, and Binding Potency toward Cytochrome P450 3A4. ACS Omega 2021; 6:13704-13718. [PMID: 34095663 PMCID: PMC8173565 DOI: 10.1021/acsomega.1c00906] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 04/07/2021] [Indexed: 06/01/2023]
Abstract
We report the synthesis and crystal structures of three new copper(II) Schiff-base complexes. The complexes have been characterized by elemental analysis and Fourier transform infrared (FT-IR) and UV-visible spectroscopies. The X-ray diffraction (XRD) analysis reveals that complexes 1 and 3 crystallize in a monoclinic space group C2/c and 2 in a triclinic space group P1̅, each adopting a square planar geometry around the metal center. We use a density functional theory method to explore the quantum chemical properties of these complexes. The calculation proceeds with the three-dimensional (3D) crystal structure characterization of the complexes in which the calculated IR and UV-vis values are comparable to the experimental results. Charge distribution and molecular orbital analyses enabled quantum chemical property prediction of these complexes. We study the drug-likeness properties and binding potentials of the synthesized complexes. The in silico outcome showed that they could serve as permeability-glycoprotein (P-gp) and different cytochrome P450 substrates. Our calculations showed that the complexes significantly bind to cytochrome P450 3A4.
Collapse
Affiliation(s)
- Tunde
L. Yusuf
- Department
of Chemical Sciences, University of Johannesburg, Doornfontein, P.O.
Box 17011, Johannesburg 2028, South Africa
| | - Segun D. Oladipo
- Department
of Chemical Sciences, Olabisi Onabanjo University, P. M. B., 2002 Ago-Iwoye, Nigeria
| | - Sizwe Zamisa
- School
of Chemistry and Physics, University of
KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa
| | - Hezekiel M. Kumalo
- Discipline
of Medical Biochemistry, School of Laboratory Medicine and Medical
Sciences, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South
Africa
| | - Isiaka A. Lawal
- Chemistry
Department, Faculty of Applied and Computer Science, Vaal University of Technology, Vanderbijlpark Campus, Boulevard, 1900 Vanderbijlpark, South Africa
| | - Monsurat M. Lawal
- Discipline
of Medical Biochemistry, School of Laboratory Medicine and Medical
Sciences, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South
Africa
| | - Nonhlangabezo Mabuba
- Department
of Chemical Sciences, University of Johannesburg, Doornfontein, P.O.
Box 17011, Johannesburg 2028, South Africa
| |
Collapse
|
9
|
Sam S, Malinga SP, Mabuba N. Carbon Nanodots Embedded on a Polyethersulfone Membrane for Cadmium(II) Removal from Water. Membranes (Basel) 2021; 11:114. [PMID: 33562886 PMCID: PMC7915239 DOI: 10.3390/membranes11020114] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 01/28/2021] [Accepted: 02/01/2021] [Indexed: 12/02/2022]
Abstract
Cadmium(II) is a toxic heavy metal in aquatic systems. As a potential solution, green carbon nanodots (CNDs) were synthesized from oats and embedded on polyethersulfone membrane (PES) via phase inversion for the adsorption of Cd2+ from water. Characterization techniques for the CNDs and PES membranes were transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), Raman spectroscopy, atomic force microscopy (AFM), contact angle and a pure water flux assessment system operated at 300 kPa. TEM results showed that the CNDs were well dispersed with a uniform shape and size (6.7 ± 2.8 nm). Raman spectroscopy revealed that the CNDs were embedded on the PES and the ID/IG ratio slightly increased, showing that the membranes maintained good structural integrity.The CNDs/PES proved to be more hydrophilic than PES. The glassy carbon electrode (GCE) in anodic stripping voltammetry (ASV) technique detected 99.78% Cd2+ removal by 0.5% CNDs/PES at optimum conditions: 30 min. contact time, at pH 5 and 0.5 ppm Cd2+ solution. The 0.5% CNDs/PES removed Cd(II) due to the hydroxyl group (-OH) and carboxyl group (-COO-) on the membrane composite. It was established that Cu2+ and Pb2+ have a significant interfering effect during the analysis of Cd2+ using GCE in ASV technique. The 0.5% CNDs/PES is recyclable because it removed above 95% of cd2+ in four cycles. In a spiked tap water sample, 58.38% of Cd2+ was sensed by GCE of which 95% was in agreement with the value obtained from inductively coupled plasma optical emission spectrometry (ICPOES).
Collapse
Affiliation(s)
| | | | - Nonhlangabezo Mabuba
- Department of Chemical Sciences (Formerly Known as Applied Chemistry), Doornfontein Campus, University of Johannesburg, P.O. Box 17011, Johannesburg 2028, South Africa; (S.S.); (S.P.M.)
| |
Collapse
|
10
|
Zwane BN, Mabuba N, Orimolade BO, Koiki BA, Arotiba OA. Photocatalytic degradation of ciprofloxacin and sulfamethoxazole on a carbon nanodot doped tungsten trioxide: degradation product study. Reac Kinet Mech Cat 2020. [DOI: 10.1007/s11144-020-01841-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
11
|
Fakude CT, Arotiba OA, Arduini F, Mabuba N. Flexible Polyester Screen‐printed Electrode Modified with Carbon Nanofibers for the Electrochemical Aptasensing of Cadmium (II). ELECTROANAL 2020. [DOI: 10.1002/elan.202060070] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Colani T Fakude
- Department of Chemical Sciences University of Johannesburg Doornfontein 2028 Johannesburg South Africa
| | - Omotayo A Arotiba
- Department of Chemical Sciences University of Johannesburg Doornfontein 2028 Johannesburg South Africa
- Centre for Nanomaterials Science Research University of Johannesburg 2028 Johannesburg South Africa
| | - Fabiana Arduini
- Department of Chemical Science and Technologies University of Rome “Tor Vergata” 00133 Rome Italy
| | - Nonhlangabezo Mabuba
- Department of Chemical Sciences University of Johannesburg Doornfontein 2028 Johannesburg South Africa
- Centre for Nanomaterials Science Research University of Johannesburg 2028 Johannesburg South Africa
| |
Collapse
|
12
|
Koiki BA, Orimolade BO, Zwane BN, Nkosi D, Mabuba N, Arotiba OA. Cu2O on anodised TiO2 nanotube arrays: A heterojunction photoanode for visible light assisted electrochemical degradation of pharmaceuticals in water. Electrochim Acta 2020. [DOI: 10.1016/j.electacta.2020.135944] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
|
13
|
|
14
|
Malefane ME, Ntsendwana B, Mafa PJ, Mabuba N, Feleni U, Kuvarega AT. In‐Situ Synthesis of Tetraphenylporphyrin/Tungsten (VI) Oxide/Reduced Graphene Oxide (TPP/WO
3
/RGO) Nanocomposite for Visible Light Photocatalytic Degradation of Acid Blue 25. ChemistrySelect 2019. [DOI: 10.1002/slct.201901589] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Mope E. Malefane
- Nanotechnology and Water Research UnitUniversity of South Africa, Florida, 1709, Rooderpoort South Africa
| | - Bulelwa Ntsendwana
- Nanotechnology and Water Research UnitUniversity of South Africa, Florida, 1709, Rooderpoort South Africa
| | - Potlako J. Mafa
- Nanotechnology and Water Research UnitUniversity of South Africa, Florida, 1709, Rooderpoort South Africa
| | - Nonhlangabezo Mabuba
- Department of Applied ChemistryUniversity of Johannesburg Doornfontein 2028, Johannesburg South Africa
| | - Usisipho Feleni
- Nanotechnology and Water Research UnitUniversity of South Africa, Florida, 1709, Rooderpoort South Africa
| | - Alex T. Kuvarega
- Nanotechnology and Water Research UnitUniversity of South Africa, Florida, 1709, Rooderpoort South Africa
| |
Collapse
|
15
|
Mushiana T, Mabuba N, Idris AO, Peleyeju GM, Orimolade BO, Nkosi D, Ajayi RF, Arotiba OA. An aptasensor for arsenic on a carbon‑gold bi-nanoparticle platform. Sensing and Bio-Sensing Research 2019. [DOI: 10.1016/j.sbsr.2019.100280] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
|
16
|
Idris AO, Mabuba N, Arotiba OA. An Exfoliated Graphite-Based Electrochemical Immunosensor on a Dendrimer/Carbon Nanodot Platform for the Detection of Carcinoembryonic Antigen Cancer Biomarker. Biosensors (Basel) 2019; 9:E39. [PMID: 30857164 PMCID: PMC6468524 DOI: 10.3390/bios9010039] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 03/01/2019] [Accepted: 03/03/2019] [Indexed: 11/17/2022]
Abstract
An electrochemical immunosensor for the quantification of carcinoembryonic antigen (CEA) using a nanocomposite of polypropylene imine dendrimer (PPI) and carbon nanodots (CNDTs) on an exfoliated graphite electrode (EG) is reported. The carbon nanodots were prepared by pyrolysis of oats. The nanocomposites (PPI and CNDTs) were characterized using X-ray powder diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), high-resolution transmission electron microscopy (HRTEM) and scanning electron microscopy (SEM). The proposed immunosensor was prepared on an exfoliated graphite electrode sequentially by drop coating CNDTs, the electrodeposition of G2-PPI (generation 2 poly (propylene imine) dendrimer), the immobilization of anti-CEA on the modified electrode for 80 min at 35 °C, and dropping of bovine serum albumin (BSA) to minimize non-specific binding sites. Cyclic voltammetry was used to characterize each stage of the fabrication of the immunosensor. The proposed immunosensor detected CEA within a concentration range of 0.005 to 300 ng/mL with a detection limit of 0.00145 ng/mL by using differential pulse voltammetry (DPV). The immunosensor displayed good stability and was also selective in the presence of some interference species such as ascorbic acid, glucose, alpha-fetoprotein, prostate-specific antigen and human immunoglobulin. Furthermore, the fabricated immunosensor was applied in the quantification of CEA in a human serum sample, indicating its potential for real sample analysis.
Collapse
Affiliation(s)
- Azeez O Idris
- Department of Applied Chemistry, University of Johannesburg, Doornfontein 2028, Johannesburg, South Africa.
| | - Nonhlangabezo Mabuba
- Department of Applied Chemistry, University of Johannesburg, Doornfontein 2028, Johannesburg, South Africa.
- Centre for Nanomaterials Science Research, University of Johannesburg, Doornfontein 2028, Johannesburg, South Africa.
| | - Omotayo A Arotiba
- Department of Applied Chemistry, University of Johannesburg, Doornfontein 2028, Johannesburg, South Africa.
- Centre for Nanomaterials Science Research, University of Johannesburg, Doornfontein 2028, Johannesburg, South Africa.
| |
Collapse
|
17
|
Orimolade BO, Koiki BA, Zwane BN, Peleyeju GM, Mabuba N, Arotiba OA. Interrogating solar photoelectrocatalysis on an exfoliated graphite–BiVO4/ZnO composite electrode towards water treatment. RSC Adv 2019; 9:16586-16595. [PMID: 35516409 PMCID: PMC9064408 DOI: 10.1039/c9ra02366f] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 05/20/2019] [Indexed: 01/11/2023] Open
Abstract
A novel photoanode consisting of an exfoliated graphite–BiVO4/ZnO heterostructured nanocomposite was fabricated. The material was characterised with scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and X-ray diffraction (XRD). Photoelectrochemical studies were carried out with cyclic/linear sweep voltammetry and chronoamperometry. The solar photoelectrochemical properties of the heterojunction photoanode were investigated through the degradation of rhodamine B in water. The results revealed that the nanoparticles of BiVO4 and ZnO were well entrapped within the interlayers of the exfoliated graphite (EG) sheets. Improved charge separation was achieved in the EG–BiVO4/ZnO composite electrode which resulted in superior photoelectrochemical performance than individual BiVO4 and ZnO electrodes. A higher degradation efficiency of 91% of rhodamine B was recorded using the composite electrode with the application of 10 mA cm−2 current density and a solution pH of 7. The highest total organic carbon removal of 74% was also recorded with the EG–BiVO4/ZnO. Data from scavenger studies were used to support the proposed mechanism of degradation. The electrode has high stability and reusability and hence lends itself to applications in photoelectrocatalysis, especially in water treatment. Band alignment between ZnO and BiVO4 on exfoliated graphite (EG) support.![]()
Collapse
Affiliation(s)
| | | | - Busisiwe N. Zwane
- Department of Applied Chemistry
- University of Johannesburg
- South Africa
| | | | - Nonhlangabezo Mabuba
- Department of Applied Chemistry
- University of Johannesburg
- South Africa
- Centre for Nanomaterials Science Research
- University of Johannesburg
| | - Omotayo A. Arotiba
- Department of Applied Chemistry
- University of Johannesburg
- South Africa
- Centre for Nanomaterials Science Research
- University of Johannesburg
| |
Collapse
|
18
|
Umukoro EH, Peleyeju MG, Idris AO, Ngila JC, Mabuba N, Rhyman L, Ramasami P, Arotiba OA. Photoelectrocatalytic application of palladium decorated zinc oxide-expanded graphite electrode for the removal of 4-nitrophenol: experimental and computational studies. RSC Adv 2018; 8:10255-10266. [PMID: 35540454 PMCID: PMC9078825 DOI: 10.1039/c8ra00180d] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Accepted: 03/08/2018] [Indexed: 12/24/2022] Open
Abstract
A novel Pd-ZnO-expanded graphite (EG) photoelectrode was constructed from a Pd-ZnO-EG nanocomposite synthesised by a hydrothermal method and characterised using various techniques such as X-ray diffractometry (XRD), Raman spectroscopy, UV-Vis diffuse reflectance spectroscopy, nitrogen adsorption-desorption analysis, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). Cyclic voltammetry and photocurrent response measurements were also carried out on the electrode. The Pd-ZnO-EG electrode was employed in the photoelectrocatalytic removal of 4-nitrophenol as a target water pollutant at a neutral pH and with a current density of 7 mA cm-2. Optical studies revealed that the Pd-ZnO-EG absorbed strongly in the visible light region. The Pd-ZnO-EG electrode showed improved photoelectrocatalytic activity in relation to ZnO-EG and EG electrodes for the removal of the 4-nitrophenol. The photocurrent responses showed that the Pd-ZnO-EG nanocomposite electrode could be employed as a good photoelectrode for photoelectrocatalytic processes and environmental remediation such as treatment of industrial waste waters. Density functional theory method was used to model the oxidative degradation of 4-nitrophenol by the hydroxyl radical which generates hydroquinone, benzoquinone, 4-nitrocatechol, 4-nitroresorcinol and the opening of the 4-nitrophenol ring. Furthermore, the hydroxyl radical is regenerated and can further oxidise the ring structure and initiate a new degradation process.
Collapse
Affiliation(s)
| | - Moses G Peleyeju
- Department of Applied Chemistry, University of Johannesburg South Africa
| | - Azeez O Idris
- Department of Applied Chemistry, University of Johannesburg South Africa
| | - Jane C Ngila
- Department of Applied Chemistry, University of Johannesburg South Africa
- Centre for Nanomaterials Science Research, University of Johannesburg South Africa
| | - Nonhlangabezo Mabuba
- Department of Applied Chemistry, University of Johannesburg South Africa
- Centre for Nanomaterials Science Research, University of Johannesburg South Africa
| | - Lydia Rhyman
- Department of Applied Chemistry, University of Johannesburg South Africa
- Computational Chemistry Group, Department of Chemistry, Faculty of Science, University of Mauritius Réduit 80837 Mauritius
| | - Ponnadurai Ramasami
- Department of Applied Chemistry, University of Johannesburg South Africa
- Computational Chemistry Group, Department of Chemistry, Faculty of Science, University of Mauritius Réduit 80837 Mauritius
| | - Omotayo A Arotiba
- Department of Applied Chemistry, University of Johannesburg South Africa
- Centre for Nanomaterials Science Research, University of Johannesburg South Africa
| |
Collapse
|
19
|
Idris AO, Mabuba N, Arotiba OA. Towards cancer diagnostics – an α-feto protein electrochemical immunosensor on a manganese(iv) oxide/gold nanocomposite immobilisation layer. RSC Adv 2018; 8:30683-30691. [PMID: 35548739 PMCID: PMC9085503 DOI: 10.1039/c8ra06135a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 08/24/2018] [Indexed: 11/25/2022] Open
Abstract
A novel electrochemical immunosensor for the quantification of α-feto protein (AFP) using a nanocomposite of manganese(iv) oxide nanorods (MnO2NRs) and gold nanoparticles (AuNPs) as the immobilisation layer is presented. The MnO2NRs was synthesised using a hydrothermal method and AuNPs were electrodeposited on a glassy carbon electrode surface. The MnO2NRs were characterised with scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM) and X-ray powder diffraction (XRD). Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to characterise the immunosensor at each stage of the biosensor preparation. The MnO2 nanorods and AuNPs were applied as the immobilisation layer to efficiently capture the antibodies and amplify the electrochemical signal. Under optimised conditions, the fabricated immunosensor was utilised for the quantification of AFP with a wide dynamic range of 0.005 to 500 ng mL−1 and detection limits of 0.00276 ng mL−1 and 0.00172 ng mL−1 (S/N = 3) were obtained from square wave anodic stripping voltammetry and EIS respectively. The nanocomposite modifier enhanced the immunosensor performance. More so, this label-free immunosensor possesses good stability over a period of two weeks when stored at 4 °C and was selective in the presence of some interfering species. A novel electrochemical immunosensor for the quantification of α-feto protein (AFP) using a nanocomposite of manganese(iv) oxide nanorods (MnO2NRs) and gold nanoparticles (AuNPs) as the immobilisation layer is presented.![]()
Collapse
Affiliation(s)
- Azeez O. Idris
- Department of Applied Chemistry
- University of Johannesburg
- South Africa
| | - Nonhlangabezo Mabuba
- Department of Applied Chemistry
- University of Johannesburg
- South Africa
- Centre for Nanomaterials Science Research
- University of Johannesburg
| | - Omotayo A. Arotiba
- Department of Applied Chemistry
- University of Johannesburg
- South Africa
- Centre for Nanomaterials Science Research
- University of Johannesburg
| |
Collapse
|
20
|
Idris AO, Mabuba N, Arotiba OA. A Dendrimer Supported Electrochemical Immunosensor for the Detection of Alpha-feto protein - a Cancer Biomarker. ELECTROANAL 2017. [DOI: 10.1002/elan.201700491] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Azeez O. Idris
- Department of Applied Chemistry; University of Johannesburg; Doornfontein 2028 Johannesburg South Africa
| | - Nonhlangabezo Mabuba
- Department of Applied Chemistry; University of Johannesburg; Doornfontein 2028 Johannesburg South Africa
- Centre for Nanomaterials Science Research; University of Johannesburg; South Africa
| | - Omotayo A. Arotiba
- Department of Applied Chemistry; University of Johannesburg; Doornfontein 2028 Johannesburg South Africa
- Centre for Nanomaterials Science Research; University of Johannesburg; South Africa
| |
Collapse
|
21
|
Idris AO, Mafa JP, Mabuba N, Arotiba OA. Nanogold modified glassy carbon electrode for the electrochemical detection of arsenic in water. RUSS J ELECTROCHEM+ 2017. [DOI: 10.1134/s1023193517020082] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
22
|
Magoda C, Nomngongo PN, Mabuba N. Magnetic iron–cobalt/silica nanocomposite as adsorbent in micro solid-phase extraction for preconcentration of arsenic in environmental samples. Microchem J 2016. [DOI: 10.1016/j.microc.2016.05.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
23
|
Affiliation(s)
- J. P. Mafa
- Department of Applied Chemistry; University of Johannesburg; Doornfontein 2028 South Africa
| | - N. Mabuba
- Department of Applied Chemistry; University of Johannesburg; Doornfontein 2028 South Africa
| | - O. A. Arotiba
- Department of Applied Chemistry; University of Johannesburg; Doornfontein 2028 South Africa
- Centre for Nanomaterials Science Research; University of Johannesburg; South Africa
| |
Collapse
|
24
|
Idris A, Mabuba N, Arotiba O. Electroanalysis of selenium in water on an electrodeposited gold-nanoparticle modified glassy carbon electrode. J Electroanal Chem (Lausanne) 2015. [DOI: 10.1016/j.jelechem.2015.10.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|