Toward the interpretation of electroreflectance spectral profiles

Hemin adsorbed on an HOPG electrode revisited

Takamasa Sagara, Hidekazu Murase, Masaharu Komatsu, Naotoshi Nakashima

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

The features of the potential-modulated UV-visible reflectance (electroreflectance) spectrum at an electrode/solution interface are discussed by comparing experimental and simulated spectra. At a basal plane of a highly oriented pyrolytic graphite (HOPG) electrode covered with a molecular layer of heroin in 0.1 M Na2B4O7 aqueous solution, the electroreflectance signal was confirmed to be proportional to the amount of adsorbed hemin interconverted between oxidized and reduced forms. The electroreflectance spectrum in response to p-polarized incident light depended little on the incident angle, and the spectral profile was different from the difference absorption spectrum between oxidized and reduced hemin in solution phase. The spectral feature of the simulated electroreflectance spectrum with the use of Fresnel equations for a stratified three-phase optical model with a thin-layer approximation was markedly different from the experimental spectrum in regard to spectral profile and incident angle dependence. These results may suggest that refinement of the optical model to predict the reflectance spectrum at an electrode surface covered with a molecular layer is necessary for the interpretation of electroreflectance spectral profiles.

Original languageEnglish
Pages (from-to)316-323
Number of pages8
JournalApplied Spectroscopy
Volume54
Issue number2
DOIs
Publication statusPublished - Jan 1 2000

Fingerprint

Hemin
Graphite electrodes
pyrolytic graphite
electrodes
profiles
Electrodes
Heroin
Absorption spectra
reflectance
aqueous solutions
absorption spectra
approximation

All Science Journal Classification (ASJC) codes

  • Instrumentation
  • Spectroscopy

Cite this

Toward the interpretation of electroreflectance spectral profiles : Hemin adsorbed on an HOPG electrode revisited. / Sagara, Takamasa; Murase, Hidekazu; Komatsu, Masaharu; Nakashima, Naotoshi.

In: Applied Spectroscopy, Vol. 54, No. 2, 01.01.2000, p. 316-323.

Research output: Contribution to journalArticle

Sagara, Takamasa ; Murase, Hidekazu ; Komatsu, Masaharu ; Nakashima, Naotoshi. / Toward the interpretation of electroreflectance spectral profiles : Hemin adsorbed on an HOPG electrode revisited. In: Applied Spectroscopy. 2000 ; Vol. 54, No. 2. pp. 316-323.
@article{6c42714d1bb84d7f850324f223544a08,
title = "Toward the interpretation of electroreflectance spectral profiles: Hemin adsorbed on an HOPG electrode revisited",
abstract = "The features of the potential-modulated UV-visible reflectance (electroreflectance) spectrum at an electrode/solution interface are discussed by comparing experimental and simulated spectra. At a basal plane of a highly oriented pyrolytic graphite (HOPG) electrode covered with a molecular layer of heroin in 0.1 M Na2B4O7 aqueous solution, the electroreflectance signal was confirmed to be proportional to the amount of adsorbed hemin interconverted between oxidized and reduced forms. The electroreflectance spectrum in response to p-polarized incident light depended little on the incident angle, and the spectral profile was different from the difference absorption spectrum between oxidized and reduced hemin in solution phase. The spectral feature of the simulated electroreflectance spectrum with the use of Fresnel equations for a stratified three-phase optical model with a thin-layer approximation was markedly different from the experimental spectrum in regard to spectral profile and incident angle dependence. These results may suggest that refinement of the optical model to predict the reflectance spectrum at an electrode surface covered with a molecular layer is necessary for the interpretation of electroreflectance spectral profiles.",
author = "Takamasa Sagara and Hidekazu Murase and Masaharu Komatsu and Naotoshi Nakashima",
year = "2000",
month = "1",
day = "1",
doi = "10.1366/0003702001949285",
language = "English",
volume = "54",
pages = "316--323",
journal = "Applied Spectroscopy",
issn = "0003-7028",
publisher = "Society for Applied Spectroscopy",
number = "2",

}

TY - JOUR

T1 - Toward the interpretation of electroreflectance spectral profiles

T2 - Hemin adsorbed on an HOPG electrode revisited

AU - Sagara, Takamasa

AU - Murase, Hidekazu

AU - Komatsu, Masaharu

AU - Nakashima, Naotoshi

PY - 2000/1/1

Y1 - 2000/1/1

N2 - The features of the potential-modulated UV-visible reflectance (electroreflectance) spectrum at an electrode/solution interface are discussed by comparing experimental and simulated spectra. At a basal plane of a highly oriented pyrolytic graphite (HOPG) electrode covered with a molecular layer of heroin in 0.1 M Na2B4O7 aqueous solution, the electroreflectance signal was confirmed to be proportional to the amount of adsorbed hemin interconverted between oxidized and reduced forms. The electroreflectance spectrum in response to p-polarized incident light depended little on the incident angle, and the spectral profile was different from the difference absorption spectrum between oxidized and reduced hemin in solution phase. The spectral feature of the simulated electroreflectance spectrum with the use of Fresnel equations for a stratified three-phase optical model with a thin-layer approximation was markedly different from the experimental spectrum in regard to spectral profile and incident angle dependence. These results may suggest that refinement of the optical model to predict the reflectance spectrum at an electrode surface covered with a molecular layer is necessary for the interpretation of electroreflectance spectral profiles.

AB - The features of the potential-modulated UV-visible reflectance (electroreflectance) spectrum at an electrode/solution interface are discussed by comparing experimental and simulated spectra. At a basal plane of a highly oriented pyrolytic graphite (HOPG) electrode covered with a molecular layer of heroin in 0.1 M Na2B4O7 aqueous solution, the electroreflectance signal was confirmed to be proportional to the amount of adsorbed hemin interconverted between oxidized and reduced forms. The electroreflectance spectrum in response to p-polarized incident light depended little on the incident angle, and the spectral profile was different from the difference absorption spectrum between oxidized and reduced hemin in solution phase. The spectral feature of the simulated electroreflectance spectrum with the use of Fresnel equations for a stratified three-phase optical model with a thin-layer approximation was markedly different from the experimental spectrum in regard to spectral profile and incident angle dependence. These results may suggest that refinement of the optical model to predict the reflectance spectrum at an electrode surface covered with a molecular layer is necessary for the interpretation of electroreflectance spectral profiles.

UR - http://www.scopus.com/inward/record.url?scp=0033904537&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0033904537&partnerID=8YFLogxK

U2 - 10.1366/0003702001949285

DO - 10.1366/0003702001949285

M3 - Article

VL - 54

SP - 316

EP - 323

JO - Applied Spectroscopy

JF - Applied Spectroscopy

SN - 0003-7028

IS - 2

ER -