Photonic crystals in biology

Poster Session, Tuesday, June 15
Theme A1 - B702
OPTICAL CHEMICAL SENSOR BASED ON POLYMER NANOFIBERS FOR
SILVER(I) ION DETECTION
Sibel Kaçmaz 1* , Kadriye Ertekin 1 , Yavuz Ergün 1 , Mehtap Özdemir 2 , Ümit Cöcen 2
1 University of Dokuz Eylul, Faculty of Arts and Sciences, Department of Chemistry, 35160, Izmir,Turkey
2 University of Dokuz Eylul, Faculty Engineering, Department of Metallurgical and Materials Engineering, 35160, Izmir,Turkey
Abstract- In this work, Ag + sensing nanofibers were produced by electrospinning of composites containing Y-5
(4(dimethylamino)benzaldehyde2-[[4(dimethylamino)phenyl]methylene]hydrazone) dye, ethyl cellulose (EC) and/or polymethyl-methacrylate
(PMMA). The fluorescence spectra of the embedded dyes in fiber and thin film form were recorded.
Presence of ionic liquid in the matrix material enhanced electrospinning process providing ionic conductivity.
Results of the studies performed in liquid phase
provide valuable information for researchers;
however, they remain far from applications in sensor
technology at this stage. The integration of liquid
components with solid state optics is not practical and
molecule-based solid state approaches employing
polymeric media should be developed.
In this context, recently, a number of ultrasensitive
fluorescent optical sensors for a variety of analytes
have been demonstrated; new strategies are still being
developed [1-3].
Electrospinning is a relatively simple and versatile
method for creating high-surface-area polymeric
fibrous membranes. In a typical process, a large static
voltage is applied to a polymer solution to generate
fine jets of solution that dry into an interconnected
membrane like web of small fibers [4]. Electrospun
fibres can be functionalized by the use of proper
indicator and auxiliary additives for desired purposes.
In this work, we reported the use of electrospun
polymer fibers as highly responsive fluorescent
optical sensors for Ag+ ions.
A series of Ag + sensitive nanofibers with various
compositions of poly-methyl-methacrylate (PMMA),
ethyl cellulose (EC), plasticizer and ionic liquid (1-
ethyl-3-methylimidazolium tetrafluoroborate) were
produced and characterized by Scanning Electron
Microscopy (SEM). The Ag + sensitive dye Y-5
4(dimethylamin)benzaldehyde2[[4(dimethylamino)ph
enyl]methylene]hydrazone dyes has been used as
sensing agent. (See Fig.1).
The fiber diameters were measured between 480-
680 nm for 40% DOP, 10% IL and 50% EC
containing composites and 1.72-2.43 μm for 25%
DOP, 25% IL and 50% PMMA containing
composites.
Upon exposure to Ag + ions the Y-5 dye exhibited
fluorescence quenching based response at 580 nm.
Fig. 3 reveals response of the sensing agent to Ag+
ions in the concentration range of 3.51×10 -07 -
1.43×10 -02 M.
Figure 2. Scanning electron microscopy (SEM) images of
EC (40% DOP, 10% IL) based nanofiber.
300
250
200
150
100
50
g
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f
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400 500 600 700
Wavelength (nm)
H 3 C
C
H 3
N
N
N
Figure 1. Chemical structure of Y-5 dye
N
CH 3
CH 3
Electrospinning was performed at 25 kV voltage
and at 0.3 mL/h flow rate. SEM micrograph of EC
based nanofibers were shown in Fig. 2.
Figure 3. Response of EC based sensing nanofibers to Ag+
ions.
*Corresponding author: sibel.kacmaz@ogr.deu.edu.tr
[1]. J. S. Yang, and T. M. Swager, J. Am. Chem. Soc., 120,
11864-11873(1998).
[2] L. H. Chen, D. W. Mcbranch, H. L. Wang, R. Helgeson,
F. Wudl, and D. G. Whitten, Proc. Natl. Acad. Sci., 96,
12287-12292 (1999).
[3] C. Fan, K. W. Plaxco, A. J. Heeger, J. Am. Chem. Soc.,
124, 5642-5643 (2002).
[4] D. H. Reneker, and I. Chun, Nanotechnology, 7, 215
(1996).
6th Nanoscience and Nanotechnology Conference, zmir, 2010 387