Studies on electropolymerization of ortho-phenylenediamine on platinum microelectrode and its detection of hydrogen peroxide and ascorbic acid using electrochemical impedance spectroscopy / Aziah Ahmad Ariffin

Poly-ortho-phenylenediatnine (PoPD) has been successfully electropolymerized and characterized on Platinum disk (125 urn internal diameters) using Electrochemical Impedance Spectroscopy (EIS) and Cyclic Voltammetry (CY). oPD was first prepared using CV by dissolving oPD monomer into Phosphate Buffer...

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Main Author:	Ahmad Ariffin, Aziah
Format:	Thesis
Language:	English
Published:	2015
Online Access:	https://ir.uitm.edu.my/id/eprint/16366/1/TM_AZIAH%20AHMAD%20ARIFFIN%20AS%2015_5.pdf
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spelling	my-uitm-ir.163662022-03-10T05:05:58Z Studies on electropolymerization of ortho-phenylenediamine on platinum microelectrode and its detection of hydrogen peroxide and ascorbic acid using electrochemical impedance spectroscopy / Aziah Ahmad Ariffin 2015 Ahmad Ariffin, Aziah Poly-ortho-phenylenediatnine (PoPD) has been successfully electropolymerized and characterized on Platinum disk (125 urn internal diameters) using Electrochemical Impedance Spectroscopy (EIS) and Cyclic Voltammetry (CY). oPD was first prepared using CV by dissolving oPD monomer into Phosphate Buffer Saline (PBS) using various monomer concentration, pH of PBS and scan rate to determine the optimum condition. The optimum condition (300 mM oPD in pH 7.2 PBS with scan rate 100 mVs⁻¹ ) recorded oxidation potential E =500 mV at the highest anodic peak current, 9.16 x 10⁵ mA cm⁻². Electropolymerization of oPD was carried out by EIS with applying the optimum condition and oxidation potential to determine the redox-kinetic parameters and electrical behavior of the system. Up to our knowledge, oPD electropolymerization on Pt disk microelectrode is firstly reported in this work. Theredox-kinetic parameters of PoPD obtained from impedance data are charge transfer resistance, Rct (1.80x 10² kΩ), diffusion coefficient, D, (1.23 x 10⁵ cms⁻¹) and double-layer capacitance, Cdl, (0.14 µf). These parameters were obtained as the impedance spectra were fitted to three proposed equivalent circuit models beginning with simple Randles Model, (R(Q[RW]) to a more complex models such as ([R(RQ)([RW]Q)] and [R([RW]C)(RC)]. They showed chi square values, X² , less than zero indicating the models tits to the impedance spectra. The PoPD coated electrode was used as analytical probes towards the detection of Hydrogen Peroxide (H₂O₂) and Ascorbic Acid (AA). EIS used to investigate the blocking ability of PoPO to the ascorbic acid and hydrogen peroxide is also firstly reported in this work. In various analytes concentrations., the impedance value of AA higher (4.4 kΩ to 6.6 kΩ) than H₂O₂ (2.8 kΩ to 3.7 kΩ) indicated the larger size of AA species impeded by PoPD layer to theelectrode surface compared with smaller size of H202 species allowed to permeate. Meanwhile, dielectric constant values were also determined from the impedance data and exhibited higher values for ascorbic acid compared hydrogen peroxide as well. PoPD formation onto the electrode surface was confirmed by FESEM by exhibited a rough and crater-like surface fanned. 2015 Thesis https://ir.uitm.edu.my/id/eprint/16366/ https://ir.uitm.edu.my/id/eprint/16366/1/TM_AZIAH%20AHMAD%20ARIFFIN%20AS%2015_5.pdf text en public mphil masters Universiti Teknologi MARA Faculty of Applied Sciences
institution	Universiti Teknologi MARA
collection	UiTM Institutional Repository
language	English
description	Poly-ortho-phenylenediatnine (PoPD) has been successfully electropolymerized and characterized on Platinum disk (125 urn internal diameters) using Electrochemical Impedance Spectroscopy (EIS) and Cyclic Voltammetry (CY). oPD was first prepared using CV by dissolving oPD monomer into Phosphate Buffer Saline (PBS) using various monomer concentration, pH of PBS and scan rate to determine the optimum condition. The optimum condition (300 mM oPD in pH 7.2 PBS with scan rate 100 mVs⁻¹ ) recorded oxidation potential E =500 mV at the highest anodic peak current, 9.16 x 10⁵ mA cm⁻². Electropolymerization of oPD was carried out by EIS with applying the optimum condition and oxidation potential to determine the redox-kinetic parameters and electrical behavior of the system. Up to our knowledge, oPD electropolymerization on Pt disk microelectrode is firstly reported in this work. Theredox-kinetic parameters of PoPD obtained from impedance data are charge transfer resistance, Rct (1.80x 10² kΩ), diffusion coefficient, D, (1.23 x 10⁵ cms⁻¹) and double-layer capacitance, Cdl, (0.14 µf). These parameters were obtained as the impedance spectra were fitted to three proposed equivalent circuit models beginning with simple Randles Model, (R(Q[RW]) to a more complex models such as ([R(RQ)([RW]Q)] and [R([RW]C)(RC)]. They showed chi square values, X² , less than zero indicating the models tits to the impedance spectra. The PoPD coated electrode was used as analytical probes towards the detection of Hydrogen Peroxide (H₂O₂) and Ascorbic Acid (AA). EIS used to investigate the blocking ability of PoPO to the ascorbic acid and hydrogen peroxide is also firstly reported in this work. In various analytes concentrations., the impedance value of AA higher (4.4 kΩ to 6.6 kΩ) than H₂O₂ (2.8 kΩ to 3.7 kΩ) indicated the larger size of AA species impeded by PoPD layer to theelectrode surface compared with smaller size of H202 species allowed to permeate. Meanwhile, dielectric constant values were also determined from the impedance data and exhibited higher values for ascorbic acid compared hydrogen peroxide as well. PoPD formation onto the electrode surface was confirmed by FESEM by exhibited a rough and crater-like surface fanned.
format	Thesis
qualification_name	Master of Philosophy (M.Phil.)
qualification_level	Master's degree
author	Ahmad Ariffin, Aziah
spellingShingle	Ahmad Ariffin, Aziah Studies on electropolymerization of ortho-phenylenediamine on platinum microelectrode and its detection of hydrogen peroxide and ascorbic acid using electrochemical impedance spectroscopy / Aziah Ahmad Ariffin
author_facet	Ahmad Ariffin, Aziah
author_sort	Ahmad Ariffin, Aziah
title	Studies on electropolymerization of ortho-phenylenediamine on platinum microelectrode and its detection of hydrogen peroxide and ascorbic acid using electrochemical impedance spectroscopy / Aziah Ahmad Ariffin
title_short	Studies on electropolymerization of ortho-phenylenediamine on platinum microelectrode and its detection of hydrogen peroxide and ascorbic acid using electrochemical impedance spectroscopy / Aziah Ahmad Ariffin
title_full	Studies on electropolymerization of ortho-phenylenediamine on platinum microelectrode and its detection of hydrogen peroxide and ascorbic acid using electrochemical impedance spectroscopy / Aziah Ahmad Ariffin
title_fullStr	Studies on electropolymerization of ortho-phenylenediamine on platinum microelectrode and its detection of hydrogen peroxide and ascorbic acid using electrochemical impedance spectroscopy / Aziah Ahmad Ariffin
title_full_unstemmed	Studies on electropolymerization of ortho-phenylenediamine on platinum microelectrode and its detection of hydrogen peroxide and ascorbic acid using electrochemical impedance spectroscopy / Aziah Ahmad Ariffin
title_sort	studies on electropolymerization of ortho-phenylenediamine on platinum microelectrode and its detection of hydrogen peroxide and ascorbic acid using electrochemical impedance spectroscopy / aziah ahmad ariffin
granting_institution	Universiti Teknologi MARA
granting_department	Faculty of Applied Sciences
publishDate	2015
url	https://ir.uitm.edu.my/id/eprint/16366/1/TM_AZIAH%20AHMAD%20ARIFFIN%20AS%2015_5.pdf
_version_	1783733513194831872

Studies on electropolymerization of ortho-phenylenediamine on platinum microelectrode and its detection of hydrogen peroxide and ascorbic acid using electrochemical impedance spectroscopy / Aziah Ahmad Ariffin

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