Photonic crystals in biology

Poster Session, Tuesday, June 15
Theme A1 - B702
Electroc hemical inve stigations of the interac tion of Albumin with Cibac ron Blue F3GA
chemically immobilized on a modified glas sy carbon electrode as a nanofilm
Sümeyra Akkaya 1 * , Mustafa Uçar 1 ,Remziye Güzel 2 , 3 , 4 and Ali Osman Solak 4
1 Afyon Kocatepe University, Faculty of Arts and Sciences, Dept. Of Chemistry, Afyonkarahisar, Turkey
2
3 mistry, Kütahya, Turkey
4 Ankara University, Faculty of Science, Department of Chemistry, Ankara, Turkey
Abstract- Benzoic acid modified glassy carbon electrode was prepared at a glassy carbon surface by the electrochemical reduction of
diazobenzoic acid tetrafluoroborate salt. Subsequently, albumin from an albumin suspension was attached to the benzoic acid modified
surface to prepare a benzoic acid-albumin nano composite film. Onto the nanocomposite film, Cibacron Blue F3GA molecules were
deposited by self-assembling technique to form GC-BA/Alb/CB-Dye surfaces. These surfaces were characterized by cyclic voltammetry,
electrochemical impedance spectroscopy , X-ray photoelectron spectroscopy, reflectance-absorption infrared spectroscopy in each step during
the fabrication process.
Human serum albumin (HSA) consists of a single
polypeptide chain containing 585 amino acid residues and is
the major soluble protein component in serum. It has many
physiological functions which contributes to colloid osmotic
blood pressure and aids in the transport, distribution, and
metabolism of many endogenous and exogenous substances
[1,2]. Cibacron Blue F3GA is a monochlorotriazine dye and
has the group specificity for albumin, dehydrogenase and
lysozyme [3]. Via the nucleophilic reaction between chloride
of its triazine ring and reactive groups of the supports
including hydroxyl or amino, Cibacron Blue F3GA can be
immobilized onto the supports for protein affinity adsorption
[4].
In this study the glassy carbon electrode surfaces were
modified with the electrochemical reduction of diazonium
salt of benzoic acid by cyclic voltammetry (CV) in the
potential range of +0.2 V and -0.8 V at a scan rate of 200
mVs -1 for ten cycles vs. Ag/AgNO 3 electrode in acetonitrile
containing 0.1 M tetrabutylammoniumtetraflouro-borate
(TBATFB).
Modification voltammogram recorded is very characteristic
for the reduction of diazonium salt, in which an irreversible
reduction CV wave of diazonium salt is indicative of the loss
of N and the formation of a diazobenzoic acid radical
2
followed by covalent binding to the carbon surface [5-6].
Modified electrodes were characterized electrochemically
using redox probes of ferricyanide, dopamine and ferrocene
by CV and electrochemical impedence spectrpscopy (EIS).
In BA modified GC electrodes, carboxylic acid groups of the
BA film were further activated by covering the GC surface
with 10 μL of 4 mM EDC/ 1 mM NHS in 10 mM PBS (pH
7.6) and incubated at room temperature for 1 h, followed by a
rinse with deionized water. After that, 4 μL of albumin in BR
buffer solution was placed on the BA-GC electrode surface as
dropping with micropipettes and dried at 4 ºC overnight. The
albumin-BA modified GC electrode was then rinsed
throughly with 10 mM PBS (pH 7.6) to remove the weakly
adsorbed protein.
Electrochemical impedance spectroscopy were used to
investigate the formation of GC-BA, GC-BA/Alb and GC-
BA/Alb/Cibacron Blue F3GA. Here, EIS was used to
monitor the fabrication process of the benzoic acid surface
modification of GC, the albumin attachment and self
assembling of organic dye layers to modified surfaces. To
investigate the interaction between albumin and dye, the
Nyquist plots of bare GC, GC-BA, GC-BA/Alb and GC-
BA/Alb/CB-Dye surfaces were recorded for the redox couple
of 1 mM Fe(CN) 3-/4- 6 mixture prepared in BR buffer of pH 2
and 6,7.
NH
O
C
CB-Dye
O NH
C
Figure 1. Schematic figure of nanofilm product.
I would like to thank Prof. Dr. Ali Osman SOLAK who
presenting us his research laboratory for our experiments.
*Corresponding author: sakkaya@aku.edu.tr
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Saunders,Philadelphia.
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aryl diaznium salt: The impact of the electrode materials on the
rate of heterogenous electron transfer. Chemical Physics, 319:
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[6] Ustundag, Z., Solak, A-O. 2009. EDTA modified galssy
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Acta, 54: 6426-6432.
6th Nanoscience and Nanotechnology Conference, zmir, 2010 381